Section 2 – Brewing with Extract and Steeped Grain
Chapter 12 - Understanding Malted Barley and Adjuncts
What is Barley and Why do we Malt it?
Barley is a member of the grass family Poaceae, and the fifth largest cultivated cereal crop in the world. It was domesticated about the same time as wheat and has been cultivated for about 8000 years. There are three varieties of barley: 2 row, 4 row, and 6 row – referring to the arrangement of the kernels around the shaft. Only two and six row are used for brewing. The kernels of six row are physically smaller than those of two row, but higher in protein. Two row has historically been considered to be superior to six row for malting and brewing, but modern malting varieties of six row make excellent beer.
[figure 76 – malting process, spraying]
Barley is harvested in the field, sorted, dried, cleaned, and stored. The malting process begins when the highest grade barley, brewing grade, is steeped in water until it has absorbed almost 50% of its initial weight in water. The barley is then drained and moved to a germination room where the actual malting process occurs. The barley is held at controlled humidity and periodically turned/moved to keep the temperature in the grainbed uniform. At this stage it is referred to as green malt. After germination, the green malt is moved to a kiln where it is carefully dried at low temperatures of 122-158°F (50-70°C) to about 4% moisture. This malt is typically referred to as base malt or lager malt.
[figure 77 – malting process, (barley)]
[figure 78 – mix and twirl tank]
The malting process allows the grain to partially germinate, making the seed’s resources available to the brewer. During germination, enzymes in the aleurone layer (See Figure 75) are released, and new enzymes are created, that break down the endosperm’s protein/carbohydrate matrix into smaller carbohydrates, amino acids and lipids, and open up the seed’s starch reserves. The endosperm is composed of large and small starch granules that are packed like bags of jellybeans in a box. The cell walls (bags) within the matrix holding the starch granules (jellybeans) are primarily composed of beta-glucans (a type of cellulose), some pentosans (gummy polysaccharide), and some protein. The box in this metaphor is the outer husk. The degree to which the enzymes tear open the bags and start unpacking the starch granules (i.e. breakdown the endosperm) for use by the growing plant (or brewers in our case) is referred to as the “modification.” One visual indicator that a maltster uses to judge the degree of modification is the length of the acrospire (plant shoot) which grows underneath the husk. The length of the acrospire in a fully modified malt will typically be 75–100% of the seed length. (Actually, the most commonly used indicator is squeezing the kernel between your fingers. A fully modified kernel will be relatively soft and yielding all over; there aren’t any hard bits left in the endosperm.) If germination continued, a plant would grow, and all of the starches that the brewer hoped to use would be used by the plant. So, the maltster gauges the germination carefully and stops the process by drying when he judges he has the proper balance between resources converted by the acrospire and resources consumed by the acrospire. [figure 79 – diagram of malting barleycorn]
The purpose of malting is to create these enzymes, break down the matrix surrounding the starch granules, prepare the starches for conversion, and then stop this action until the brewer is ready to utilize the grain. After modification, the grain is dried and the rootlets are knocked off by tumbling. The kiln drying of the new malt denatures (destroys) a lot of the different enzymes, but several types remain, including the ones necessary for starch conversion. The amount of enzymatic starch conversion potential that a malt has is referred to as its “diastatic power”. Malted barley is the principal source of the sugars (principally maltose) that are fermented into beer. From a brewer’s point of view, there are basically two kinds of malts, those that need to be mashed and those that don’t. Mashing is the hot water soaking process that provides the right conditions for the enzymes to convert the grain starches into fermentable sugars. The basic light colored malts such as pale ale malt, pilsener malt and malted wheat need to be mashed to convert the starches into fermentable sugars. These malts make up the bulk of the wort’s fermentable sugars. Some of these light malts are kilned or toasted at higher temperatures to lend different tastes e.g., Biscuit, Vienna, Munich, Brown. The toasting destroys some of their diastatic power. The diastatic power of a particular malt will vary with the type of barley it is made from. Two row barley is preferred variety for all-malt beers, having a bit higher yield per pound, lower protein levels, and claiming a more refined flavor than six row. However, six row has a little higher diastatic power than two row. Historically, the higher protein level of six row barley (which can produce a very heavy bodied beer) led brewers to thin the wort with low protein grains like corn and rice. Brewers were able to take advantage of six row barley’s higher diastatic power to achieve full conversion of the mash in spite of the non-enzymatic starch sources (adjuncts). Besides the lighter-colored base and toasted malts, there is a group of malts that don’t need to be mashed, and these are often referred to as “specialty malts.” They are used for flavoring and have no diastatic power whatsoever. Some of these malts have undergone special heating processes in which the starches are converted to sugars by heat and moisture right inside the hull. As a result, they contain more complex sugars, most of which do not ferment, leaving a pleasant caramel-like sweetness. These pre-converted malts (called caramel or crystal malts) are available in different roasts or colors (denoted by the color unit Lovibond), each having a different degree of fermentability and characteristic sweetness (e.g., Crystal 40°L, Crystal 60°L). Also within the specialty malt group are the roasted malts. These malts are produced by roasting at high temperatures, giving them a deep red/brown or black color (e.g. Chocolate malt 350°L). None of the specialty malts need to be mashed, they can simply be steeped in hot water to release their character. These grains are very useful to the extract brewer, making it easy to increase the complexity of the wort without much effort. Roasted malts do not contribute fermentable sugars, just flavor compounds.Lastly, there are fermentables not derived from malted barley that are called “adjuncts.” Adjuncts are any starch or sugar source that doesn’t come from malted grain. They include refined sugars, corn and rice syrups, un-malted rye and wheat, and unmalted barley. They are not to be scorned; some adjuncts like wheat and unmalted roasted barley are essential to certain beer styles. Whole brewing traditions like Belgian Lambic, American Lager, and Irish Stout depend on the use of adjuncts. Adjuncts made from unmalted grains must be mashed with enzymatic malts to convert their starches to fermentable sugars. Roasted Barley is an exception to this rule because its starches have been converted by high roasting, and can be steeped.
[figure 78 – mix and twirl tank]
The malting process allows the grain to partially germinate, making the seed’s resources available to the brewer. During germination, enzymes in the aleurone layer (See Figure 75) are released, and new enzymes are created, that break down the endosperm’s protein/carbohydrate matrix into smaller carbohydrates, amino acids and lipids, and open up the seed’s starch reserves. The endosperm is composed of large and small starch granules that are packed like bags of jellybeans in a box. The cell walls (bags) within the matrix holding the starch granules (jellybeans) are primarily composed of beta-glucans (a type of cellulose), some pentosans (gummy polysaccharide), and some protein. The box in this metaphor is the outer husk. The degree to which the enzymes tear open the bags and start unpacking the starch granules (i.e. breakdown the endosperm) for use by the growing plant (or brewers in our case) is referred to as the “modification.” One visual indicator that a maltster uses to judge the degree of modification is the length of the acrospire (plant shoot) which grows underneath the husk. The length of the acrospire in a fully modified malt will typically be 75–100% of the seed length. (Actually, the most commonly used indicator is squeezing the kernel between your fingers. A fully modified kernel will be relatively soft and yielding all over; there aren’t any hard bits left in the endosperm.) If germination continued, a plant would grow, and all of the starches that the brewer hoped to use would be used by the plant. So, the maltster gauges the germination carefully and stops the process by drying when he judges he has the proper balance between resources converted by the acrospire and resources consumed by the acrospire. [figure 79 – diagram of malting barleycorn]
The purpose of malting is to create these enzymes, break down the matrix surrounding the starch granules, prepare the starches for conversion, and then stop this action until the brewer is ready to utilize the grain. After modification, the grain is dried and the rootlets are knocked off by tumbling. The kiln drying of the new malt denatures (destroys) a lot of the different enzymes, but several types remain, including the ones necessary for starch conversion. The amount of enzymatic starch conversion potential that a malt has is referred to as its “diastatic power”. Malted barley is the principal source of the sugars (principally maltose) that are fermented into beer. From a brewer’s point of view, there are basically two kinds of malts, those that need to be mashed and those that don’t. Mashing is the hot water soaking process that provides the right conditions for the enzymes to convert the grain starches into fermentable sugars. The basic light colored malts such as pale ale malt, pilsener malt and malted wheat need to be mashed to convert the starches into fermentable sugars. These malts make up the bulk of the wort’s fermentable sugars. Some of these light malts are kilned or toasted at higher temperatures to lend different tastes e.g., Biscuit, Vienna, Munich, Brown. The toasting destroys some of their diastatic power. The diastatic power of a particular malt will vary with the type of barley it is made from. Two row barley is preferred variety for all-malt beers, having a bit higher yield per pound, lower protein levels, and claiming a more refined flavor than six row. However, six row has a little higher diastatic power than two row. Historically, the higher protein level of six row barley (which can produce a very heavy bodied beer) led brewers to thin the wort with low protein grains like corn and rice. Brewers were able to take advantage of six row barley’s higher diastatic power to achieve full conversion of the mash in spite of the non-enzymatic starch sources (adjuncts). Besides the lighter-colored base and toasted malts, there is a group of malts that don’t need to be mashed, and these are often referred to as “specialty malts.” They are used for flavoring and have no diastatic power whatsoever. Some of these malts have undergone special heating processes in which the starches are converted to sugars by heat and moisture right inside the hull. As a result, they contain more complex sugars, most of which do not ferment, leaving a pleasant caramel-like sweetness. These pre-converted malts (called caramel or crystal malts) are available in different roasts or colors (denoted by the color unit Lovibond), each having a different degree of fermentability and characteristic sweetness (e.g., Crystal 40°L, Crystal 60°L). Also within the specialty malt group are the roasted malts. These malts are produced by roasting at high temperatures, giving them a deep red/brown or black color (e.g. Chocolate malt 350°L). None of the specialty malts need to be mashed, they can simply be steeped in hot water to release their character. These grains are very useful to the extract brewer, making it easy to increase the complexity of the wort without much effort. Roasted malts do not contribute fermentable sugars, just flavor compounds.Lastly, there are fermentables not derived from malted barley that are called “adjuncts.” Adjuncts are any starch or sugar source that doesn’t come from malted grain. They include refined sugars, corn and rice syrups, un-malted rye and wheat, and unmalted barley. They are not to be scorned; some adjuncts like wheat and unmalted roasted barley are essential to certain beer styles. Whole brewing traditions like Belgian Lambic, American Lager, and Irish Stout depend on the use of adjuncts. Adjuncts made from unmalted grains must be mashed with enzymatic malts to convert their starches to fermentable sugars. Roasted Barley is an exception to this rule because its starches have been converted by high roasting, and can be steeped.
Malt Flavor Development
[Figure 80 – The colors of malt.]
Maltsters usually divide the malt world into four types: base malts, kilned malts (including highly kilned), roasted, and kilned & roasted. Varying the moisture level, time, and temperature develops the characteristic flavors and colors of each specialty malt. Caramelization and Maillard reactions both play a role in the development of the wide variety of flavors in these malts and the beers made from them.
Caramelization is the thermal decomposition of sugar and it occurs at high temperatures (see sidebar). It is a sugar-to-sugar reaction and depends on low moisture to occur. Maillard reactions are different and can occur at a range of temperatures, starting as low as 120°F, up through 450°F (48-230°C). Maillard reactions occur between an amino acid and a sugar, producing volatile low molecular weight flavor compounds and higher molecular weight compounds like reductones and melanoidins. Reductones can oxidize and bind oxygen to improve flavor stability. Melanoidins are the browning aspect of the Maillard reaction.
Both types of reactions can generate some of the same flavors like toffee, molasses and raisin, but generally caramelization reactions are responsible for the toffee sweet caramel flavors in malt, while Maillard reactions are responsible for the malty, toasty, biscuity flavors associated with baking. The low temperature, high moisture Maillard reactions produce malty and fresh bread flavors, and the high temperature, low moisture Maillard reactions produce the toasty and biscuit flavors. The kilned malts like pale ale malt, and Vienna malt are heated dry (3-10% moisture) at low temperatures (120-160°F/50-70°C) to retain their diastatic enzymes. The flavors expressed are lightly grainy with hints of toast and warmth. Aromatic and Munich malt are kilned at higher temperatures (195-220°F/ 90-105°C) to produce richly malty and bready flavors. Only Maillard reactions are involved.[figure 81 – drum oven]
The caramel malts like Caramel 60L and Caramel 120L, are produced by roasting green malt, i.e., malt that was not dried by kilning after germination. These malts are put into a roaster and heated to the starch conversion range of 150-158°F (65-70°C). The converted sugars are in a semi-liquid state inside the kernel. After conversion, these malts are roasted at higher temperatures of 220-320°F (105-160°C), depending on the degree of color wanted. Roasting at these temperatures causes the sugars inside the kernels to caramelize, breaking them down and re-combining them into less-fermentable forms. Maillard reactions are also occurring and cause darkening of the sugars. The lighter caramel malts have a light honey to caramel flavor, while the darker caramel malts have a richer caramel and toffee flavor with hints of burnt sugar and raisin at the darkest roasts. The kilned-and-roasted malts are Amber, Brown, Chocolate, and Black malt. These malts start out green like the caramel malts above but are kilned to a lower percentage of moisture (5-15%) before roasting. Amber malts are produced by roasting fully kilned pale ale malt at temperatures up to 335°F (170°C). These temperatures give the malt the characteristic toasty, biscuity, and nutty flavors. Brown malts are roasted longer than amber malts and achieve a very dry dark toast flavor, with color equal to that of the caramel malts. Chocolate malt starts out with more moisture than Brown malt does, but less than caramel malt as it goes to roasting. The roasting process begins at about 165°F (75°C) and is steadily increased to over 325°F (160°C). At this point the malt begins fuming, and as the temperature is raised further to 420°F (215°C), the fumes turn blue, and the malt develops chocolately flavors. Some degree of caramelization occurs, but the majority of the flavors are from Maillard reactions. Black (Patent) malts are roasted to slightly higher temperatures of 428-437°F (220-225°C) producing coffee-like flavors. The malt will actually burn at temperatures exceeding 480°F (250°C), so the trick is to spray the roasted malt with water at the critical point in time, and this was the basis of the invention of Black Patent malt. Roast barley is produced in a similar manner, but the difference is that it was never malted to begin with. To summarize, kilning produces bread-like flavors from the low temperature, low moisture Maillard reactions. Roasting dry malts increases the Maillard reactions and accentuates the malt flavors of biscuit and toast. Roasting green malt causes both Maillard and caramelization reactions that produce sweet toffee flavors. Kilning and roasting of green malt at high temperatures produces the chocolate and coffee-like flavors.
The caramel malts like Caramel 60L and Caramel 120L, are produced by roasting green malt, i.e., malt that was not dried by kilning after germination. These malts are put into a roaster and heated to the starch conversion range of 150-158°F (65-70°C). The converted sugars are in a semi-liquid state inside the kernel. After conversion, these malts are roasted at higher temperatures of 220-320°F (105-160°C), depending on the degree of color wanted. Roasting at these temperatures causes the sugars inside the kernels to caramelize, breaking them down and re-combining them into less-fermentable forms. Maillard reactions are also occurring and cause darkening of the sugars. The lighter caramel malts have a light honey to caramel flavor, while the darker caramel malts have a richer caramel and toffee flavor with hints of burnt sugar and raisin at the darkest roasts. The kilned-and-roasted malts are Amber, Brown, Chocolate, and Black malt. These malts start out green like the caramel malts above but are kilned to a lower percentage of moisture (5-15%) before roasting. Amber malts are produced by roasting fully kilned pale ale malt at temperatures up to 335°F (170°C). These temperatures give the malt the characteristic toasty, biscuity, and nutty flavors. Brown malts are roasted longer than amber malts and achieve a very dry dark toast flavor, with color equal to that of the caramel malts. Chocolate malt starts out with more moisture than Brown malt does, but less than caramel malt as it goes to roasting. The roasting process begins at about 165°F (75°C) and is steadily increased to over 325°F (160°C). At this point the malt begins fuming, and as the temperature is raised further to 420°F (215°C), the fumes turn blue, and the malt develops chocolately flavors. Some degree of caramelization occurs, but the majority of the flavors are from Maillard reactions. Black (Patent) malts are roasted to slightly higher temperatures of 428-437°F (220-225°C) producing coffee-like flavors. The malt will actually burn at temperatures exceeding 480°F (250°C), so the trick is to spray the roasted malt with water at the critical point in time, and this was the basis of the invention of Black Patent malt. Roast barley is produced in a similar manner, but the difference is that it was never malted to begin with. To summarize, kilning produces bread-like flavors from the low temperature, low moisture Maillard reactions. Roasting dry malts increases the Maillard reactions and accentuates the malt flavors of biscuit and toast. Roasting green malt causes both Maillard and caramelization reactions that produce sweet toffee flavors. Kilning and roasting of green malt at high temperatures produces the chocolate and coffee-like flavors.
Common Malt Types and Usages
Note: There are a few trademarked products in the following list. I have listed them because they best represent a particular style of malt that is commonly used for a particular flavor or purpose. But this is an incomplete list; every malting house has their own specialties and I don’t come close to listing every malt. Typical Lovibond color values are listed as °L.
Base Malts – (need to be mashed)
Lager /Pilsener Malt 2°L
The name comes from the fact that pale lagers are the most common style of beer and this is the type of malt used to produce them. Lager malt can be used for brewing nearly every other style as well. More lager malt is produced than all other types combined; it is the base malt for the world of beer.The barley can be either 2 row or 6 row, although the label “Pilsener malt” is usually reserved for 2 row varieties. “Pilsener” may also indicate a malt with lower modification compared to other base malt products from the same maltster. After germination, lager malt is carefully heated in a kiln to 90°F for the first day, withered at 120–140°F for 12-20 hours and then cured at 175-185°F for 4–48 hours depending on the maltster. This produces a malt with fine mild flavor and excellent enzyme potential.
Pale Ale Malt 3°L
This malt type is kilned at higher temperatures than lager malt, giving a slightly toastier malt flavor well suited to Pale Ales and will produce a golden to pale amber beer.
Wheat Malt 3°L
Wheat has been used for brewing beer nearly as long as barley and has equal diastatic power. Malted wheat is used for 5–70% of the mash depending on the style. Wheat has no outer husk and therefore has fewer tannins than barley. It is generally smaller than barley and contributes more protein to the beer, aiding in head retention. But it is much stickier than barley due to the higher protein content and may cause lautering problems if not given a protein rest during the mash. Rice hulls are commonly added to the mash to help with lautering.
Rye Malt 3°L
Malted rye is not common but is gaining in popularity. It can be used as 5–10% of the grain bill for a rye “spicy” note. It is even stickier in the mash than wheat and should be handled accordingly.
Kilned Malts – (need to be mashed)
These malts are commonly produced by increasing the curing temperatures used for base malt production, but they can also be made at home by toasting base malt in the oven. Suggested times and temperatures are given in Chapter 21.
Vienna Malt 4°L
This malt is lighter and sweeter than Munich malt and is a principal ingredient of light amber beers. Retains enough enzymatic power to convert itself but is often used with a base malt in the mash. Typically used as 10-40% of the grainbill, depending on beer style.
Munich Malt 10°L
This malt has an amber color and gives a very malty flavor. This malt has just enough diastatic power to convert itself but is usually used in conjunction with a base malt in the mash. This malt is used as 10-60% for Oktoberfests, Bocks, and many others, including pale ales.
Aromatic™ Malt 20°L (aka Melanoidin Malt)
This malt is similar to a dark Munich 20°L, and in some cases probably is literally that. Very low diastatic power, but wonderful rich malt flavor and aromas. It contributes a deep amber or walnut brown color to beer. Use as 5-10% of the grainbill for accent.
Amber Malt 25°L (aka Biscuit™, Victory™)
This fully toasted, lightly roasted malt is used to give the beer a bread and biscuits flavor. It is typically used as 10% of the grainbill. Gives a deep amber color to the beer.
Brown Malt 60°L
This malt is getting hard to find because it only used in a couple styles like Old Ale, Porter, and Stout. It has a very dry, roasted character that is between Amber and Chocolate Malt, but it is not sweet. Kind of like pure bread crust. Use as 5-10% depending on style.
Caramel Malts – (may be steeped or mashed)
Caramel malts (aka. Crystal malt) have undergone a special heat “stewing” process after the malting which converts the starches and liquefies the sugar inside the kernels. These malts are roasted at various temperatures to caramelize the sugars to different degrees and yield a range of flavors, from honey sweet to toffee to dark caramel. The same color rating from different maltsters can have different flavors due to individual techniques; malting is as much of an art as brewing. Caramel malts are used to some degree in most beer styles. They are ideal for adding aroma and body to extract beers by steeping, but it is possible to overdo it and make the beer cloyingly sweet. Caramel malts are typically added in half pound amounts to a total of 5–15% of the grain bill for a 5 gallon batch.
Carapils Malt 3°L (Briess) Also known as Dextrin Malt. This malt is used at 1-5% of the grain bill and enhances the body, mouthfeel and foam stability of the beer, without affecting the color or flavor. A common amount for a five gallon batch is a half pound. Carapils is very hard and difficult to crush. Consequently, it does not give a good yield from steeping even though it is fully converted like other caramel malts.
Caramel 10 10°L This malt adds a light honey-like sweetness and some body to the finished beer.
Honey Malt 25°L Also known as Brumalt, this malt has a rich honey flavor that is very versatile.
Caramel 40 40°L The additional color and light caramel sweetness of this malt is perfect for pale ales and amber lagers.
Caramel 60 60°L This is the most commonly used caramel malt, also known as medium crystal. It is well suited for pale ales, English style bitters, porters and stouts. It adds a full caramel taste and body to the beer.
Caramel 80 80°L This malt is used for making reddish colored beers and gives a lightly-bittersweet caramel flavor.
Caramel 120 120°L This malt adds a lot of color. It has a toasted, bittersweet caramel flavor, with hints of burnt sugar and raisin. Useful in small amounts to add complexity or in greater amounts for old ales, barleywines and doppelbocks.
Special B 150°L (Cargill) This unique Belgian malt has a definite roasty/toasty flavor consisting of dark caramel and raisin. Used in moderation (1⁄4–1⁄2 lb.), it is very good in brown ales, porter, and doppelbocks. Larger amounts, i.e., more than a half pound in a 5 gallon batch, will lend a plum-like flavor to Abbey Ale styles like Dubbel.
Carapils Malt 3°L (Briess) Also known as Dextrin Malt. This malt is used at 1-5% of the grain bill and enhances the body, mouthfeel and foam stability of the beer, without affecting the color or flavor. A common amount for a five gallon batch is a half pound. Carapils is very hard and difficult to crush. Consequently, it does not give a good yield from steeping even though it is fully converted like other caramel malts.
Caramel 10 10°L This malt adds a light honey-like sweetness and some body to the finished beer.
Honey Malt 25°L Also known as Brumalt, this malt has a rich honey flavor that is very versatile.
Caramel 40 40°L The additional color and light caramel sweetness of this malt is perfect for pale ales and amber lagers.
Caramel 60 60°L This is the most commonly used caramel malt, also known as medium crystal. It is well suited for pale ales, English style bitters, porters and stouts. It adds a full caramel taste and body to the beer.
Caramel 80 80°L This malt is used for making reddish colored beers and gives a lightly-bittersweet caramel flavor.
Caramel 120 120°L This malt adds a lot of color. It has a toasted, bittersweet caramel flavor, with hints of burnt sugar and raisin. Useful in small amounts to add complexity or in greater amounts for old ales, barleywines and doppelbocks.
Special B 150°L (Cargill) This unique Belgian malt has a definite roasty/toasty flavor consisting of dark caramel and raisin. Used in moderation (1⁄4–1⁄2 lb.), it is very good in brown ales, porter, and doppelbocks. Larger amounts, i.e., more than a half pound in a 5 gallon batch, will lend a plum-like flavor to Abbey Ale styles like Dubbel.
Roasted Malts – (may be steeped or mashed)
These highly roasted malts contribute a bitter chocolate, coffee, or burnt toast flavor to brown ales, porters, and stouts. Obviously these malts should be used in moderation. Some brewers recommend that they be added towards the end of the mash to reduce the acrid bite that these malts can contribute. This practice will produce a smoother beer for people brewing with naturally “soft” or low bicarbonate water. These malts are typically used in small amounts and may be ground finely to achieve a better color contribution with a smaller addition.
Rostmalz 300-500°L
This group of German roast malts are generally smoother in roast character than their North American counterparts. The malts range from a light Chocolate-type malt to a Black Malt suitable for Munich Dunkel and Schwarzbier.
Chocolate Malt 300-400L
Used in small amounts (1⁄2 lb. for 5 gal.) for brown ale and extensively (1 lb.) in porters and stouts, this malt has a bittersweet chocolate flavor, pleasant roast character, and contributes a deep ruby black color. Using too much will dominate the character of the beer.
De-bittered Black Malt 500L
This special roast malt has had 60% of the husk removed prior to malting, creating a much smoother roasted character in the beer.
Roast Barley 500L
This is not actually a malt, but highly roasted plain barley. It has a dry, distinct coffee taste and is the signature flavor of Irish/dry Stouts. It has less of a charcoal bite to it than Black Patent. Use about 1⁄2-1 lb. per 5 gallons for Stout.
Black (Patent) Malt 500-600L
This is the blackest of the black. It should be used sparingly, generally less than a 1⁄2 lb. per 5 gallons. It contributes a highly roasted flavor that can actually be quite unpleasant if used in excess. It is useful for contributing color and/or setting a “limit” on the sweetness of other beer styles using a lot of caramel malt; one or two ounces is useful for this purpose.
[figure 82 – Flaked grains]Figure 82—Some of the common flaked adjuncts: (from top, left to right) flaked oats, flaked wheat, flaked rye, flaked barley, flaked corn, and flaked rice.
Other Grains and Adjuncts
As I may have mentioned earlier, an adjunct is any fermentable starch source or sugar that doesn't from malted grain. Starch adjuncts would be added to the mash, sugar adjuncts could be added to the mash or directly to the kettle. There are two types of starch adjuncts: grits and flakes. Flaked grains are pre-gelatinized – they have been pre-cooked with steam. They can be added directly to the mash but will convert better if milled with the rest of the grains. Grits are grain that has been de-germed and coarse ground. They need to be cooked, like on the stove, before adding to the mash. Corn grits are commonly available as corn meal and hominy grits.
Flaked Oats
Oats are wonderful in a porter or stout. Oatmeal lends a smooth, silky mouthfeel and a creaminess to a stout that must be tasted to be understood. Oats are available whole, steel-cut (i.e. grits), rolled, and flaked. Rolled and flaked oats have had their starches gelatinized (made soluble) by heat and pressure, and are most readily available as “Instant Oatmeal” in the grocery store. Whole oats and “Old Fashioned Rolled Oats” have not had the degree of gelatinization that Instant have had and must be cooked before adding to the mash. “Quick” oatmeal has had a degree of gelatinization but does benefit from being cooked before adding to the mash. Cook according to the directions on the box (but add more water) to ensure that the starches will be fully utilized. Use 0.5-1.5 lb. per 5 gal batch. Oats need to be mashed with barley malt (and its enzymes) for conversion.
Flaked Corn (Maize)
Flaked corn is a common adjunct in British bitters and milds and used to be used extensively in American light lager (although today corn grits are more common). Properly used, corn will lighten the color and body of the beer without overpowering the flavor. Use 0.5-2 lb. per 5 gal batch. Corn must be mashed with base malt.
Flaked Barley
Flaked unmalted barley is often used in Stouts to provide protein for head retention and body. It can also be used in other strong ale styles. Use 0.5-1 lb. per 5 gal batch. Flaked barley must be mashed with base malt.
Flaked Wheat
Unmalted wheat is a common ingredient in wheat beers, and is essential to styles like Belgian Lambic and Wit. It can add starch haze and higher levels of protein than malted wheat. Flaked wheat also imparts more wheat flavor “sharpness” and a thicker mouthfeel than malted wheat. Use 0.5-2 lb. per 5 gal batch or up to 50% in classic witbier or lambic recipes. Must be mashed with base malt.
Flaked Rice
Rice is the other principal adjunct used in American and Japanese light lagers. Rice has very little flavor and makes for a drier tasting beer than corn. Use 0.5-2 lb. per 5 gal batch. It must be mashed with base malt. Whole rice needs to be cooked in a cereal mash to effectively utilize it in the mash.
Oat and Rice Hulls
Not an adjunct per se, the hulls of oats and rice are not fermentable, but they can be useful in the mash. The hulls provide bulk and help prevent the mash from settling and becoming stuck during the sparge. This can be very helpful when making wheat or rye beers with a low percentage of barley malt and barley husks. Use 2-4 quarts of oat or rice hulls for 6-10 lbs. of wheat if doing an all-wheat beer. The barley hull is 5% of the kernels weight, so 5% of the adjunct weight is a good place to start. Do not exceed 3% by weight of the total grainbill or you will start tasting them as astringency in the beer.
Figure 76 – At the beginning of malting, the barley is steeped for a total of 38-46 hours. (photo courtesy of Briess Malting Co.)
Figure 77 - The end of steeping is signaled by the emergence of the rootlets, or “chits.” Once the barley is chitted, it must be moved to the germination tank where it will have more oxygen. (photo courtesy of Briess Malting Co.)
Figure 78—After steeping, the malt is moved to a germination bed where it is aerated and turned over several days to obtain uniform growth. The malt spends about 4 days there before it is dried in a kiln room. (photo courtesy of Briess Malting Co.)
Determining % Extract Yield with Congress Mash
In a Congress mash, 50 grams of finely ground malt is infused with 200 milliliters of warm distilled water to reach a temperature of 45 °C (113 °F). The beaker is placed in a warm water bath to maintain that temperature for 30 minutes. The mash beaker is then heated at a rate of 1 °C per minute to 70 °C (158 °F) and infused with 100 milliliters of 70 °C water.
The mash is held at 70 °C for 60 minutes, and then gradually cooled to room temperature by the addition of cold water. The total weight of the mash is adjusted to 450 grams with more distilled water, and drained through filter paper. The wort is measured for specific gravity to an accuracy of 0.00001 and then converted to %Extract As-Is (FGAI) by means of the ASBC Reference Tables for Extract Determination of Malt and Cereals. The percent moisture is determined from another sample of malt from the same lot, and that measurement is used to calculate the %Extract–Fine Grind, Dry Basis (FGDB).
Figure 79—A simplified diagram of a barley kernel during malting, showing a progressive picture of how the acrospire (the plant shoot) grows along one side of the kernel. As it grows, pre-existing enzymes are released and new enzymes are created in the aleurone layer, which “modify” the endosperm (the protein/carbohydrate matrix starch reserve) for the acrospire’s use.
Table 14 – Caramelization Temperatures
Caramelization is a non-enzymatic browning reaction, like Maillard Reactions, but occurs at much higher temperatures. It involves the breakdown of the sugar molecule into components that then react to form aroma and flavor compounds. Maillards are lower temperature reactions of a sugar and an amino acid.
Figure 80 - The many colors of malt.
Figure 81 – After kilning, specialty malts like Caramel and Chocolate are roasted at high temperatures to produce caramelization and Maillard reactions for distinctive flavors. (photo courtesy of Briess Malting Co.)
Table 15 – Example Malt Analysis Numbers
How to Read a Malt Analysis Sheet
Every batch of malt is unique, so every lot is tested, sometimes multiple times to check the consistency of large batches. The requirements differ across the various types of malt, depending on the primary usage and individual customer needs. At a minimum, each lot is tested for % Moisture, Yield, and Color. There are two ways of measuring the yield, %Extract and Hot Water Extract. The other malt testing parameters are typically: size characterization, protein levels, modification, diastatic power, and color. Example values for various malt types are given in Table 15 for comparison.
Extract—Fine Grind, Dry Basis A malt analysis sheet does not give the malt’s yield in points per pound per gallon. Instead, what you will most likely see for North American and European malts is a weight percentage called % Extract– Fine Grind, Dry Basis (FGDB). This percentage is the maximum soluble extract that the malt will yield when mashed, and is typically 80% for base malt. This soluble extract percentage equates to 37 PPG.When a malting house analyzes a malt sample to determine its extract yield, it conducts a “Congress mash” (named for the European Brewing Convention (EBC) of 1975 which standardized the procedure). A Congress mash consists of a multi-infusion mash using a standard weight of finely ground malt (i.e., flour). The mash is continually stirred over a two hour period and then drained for another hour. These times may not seem remarkable until you consider that the malt test sample is only 50 grams! This procedure yields the maximum soluble extract as a weight percentage of the original sample. This yield is known as the %Extract–Fine Grind, As-Is (FGAI). It is called “As-Is” because properly kilned malt contains about 4% moisture by weight. To compare different lots of malt with different moisture levels, this weight needs to be accounted for in the extract calculation. Therefore the basis of comparison, and the number you will most consistently see on an analysis, is the Fine Grind, Dry Basis (FGDB)— corresponding to a malt that has been oven-dried to zero moisture. Extract yield will be discussed further in Chapter 18.
The moisture content for the lot should be listed on the certificate of analysis, and should be 2- 4% for base and kilned malts. Caramel and roast malts typically have more moisture at 5-6%, but it should always be less than 6%.
Extract– Coarse Grind, As-Is and Dry BasisCoarse Grind represents a mill setting that is closer to what many professional breweries would use. The same Congress mash method is used to determine the %Extract–Coarse Grind, As-Is (CGAI), and the moisture is measured to calculate the Dry Basis value. The CGAI is a slightly more realistic number for gauging the extract potential of a malt, but it’s still a maximum that very few professional breweries would attain.Extract–Coarse Grind is not measured for most specialty malts due to the extra time and effort it takes. Professional brewers are not as concerned about the yield of specialty malts because they usually only represent a small percentage of the grain bill. Thus, the standard parameter of FGDB is the only value that is determined for specialty malts like Caramel, Chocolate, and Roast.
Fine/Coarse DifferenceThe F/C Difference value is simply the percent difference between the fine and coarse grind numbers (both As-Is and Dry Basis—same difference). This value allows the brewer to quickly convert between the two parameters. For example, looking at the numbers for Munich Malt in Table 15, the % Extract for Coarse Grind, Dry Basis, is 2% less than the %Extract Fine Grind, Dry Basis, as indicated by F/C. The F/C Difference also serves as an indicator of malt modification, although the soluble/total protein ratio is most often used.
Hot Water Extract (HWE)This parameter may be seen on malt analyses from the UK and Australia, where they utilize a single temperature infusion mash method that differs from the ASBC and EBC Congress mash methods. The main difference is that the malt sample is mashed at 65°C/ 149°F for 1 hour. HWE (As-Is) is measured as Liter•Degrees/Kilogram, and as a unit, it is equivalent to PPG when the metric conversion factors for volume and weight are applied. (Note: points/pound/gallon = gallon•degrees/pound). The conversion factor is HWE = 8.345 x PPG. However, the grind/mash procedures for HWE and %Extract differ enough that the measurements are not actually equivalent, even though they are close. The best analogy I can think of is the trying to compare the power ratings of a racecar to a farm tractor—power is power, but the way it is expressed and utilized is different. That being said, if you get a malt sheet for Pale Ale malt with an HWE (As-Is) of 308 liter°/kg, the conversion of that number by 8.345 to 37 PPG is close enough for homebrewing purposes.
ColorHistorically, the color of beer and brewing malts has been rated as degrees Lovibond (°L). This system was created in 1883 by J.W. Lovibond, and consisted of glass slides of various shades that could be combined to produce a range of colors. In 1950, the American Society of Brewing Chemists (ASBC) adopted the utilization of optical spectrophotometers to measure the absorptance of a specific wavelength of light (430 nanometers) through a standard-sized sample and the Standard Reference Method (°SRM) for determining color was born. The SRM method was originally set up to approximate the Lovibond scale and the two scales can be considered to be nearly identical for most of their range. However, the resolution of a spectrophotometer diminishes greatly as the worts darken and very little light can penetrate the sample to reach the detector. The human eye is better than a spectrophotometer at distinguishing very narrow differences in color when provided with consistent, precise references. More information is conveyed from the variety of wavelengths of visible light coming from a sample than can be conveyed by a single wavelength. There is less variation in a single wavelength measurement, but there is also a corresponding loss in range. For this reason, the Lovibond scale is still in use today, in the form of precision visual comparators. The use of the comparator is most prevalent in the malting industry, and thus the color of malts is discussed as °L, while beer color is discussed as °SRM, though the basis (absorptance at 430 nm) is the same. See Figure 76 and the °SRM color samples on the inside of the front cover. Prior to 1990, the European Brewing Congress (EBC) used a different wavelength for measuring absorptance, and conversion between the two methods was an approximation. Today, the EBC scale uses the same wavelength for measurement, but uses a smaller sample glass. The current EBC scale for rating beer color is about twice (1.97X) the °SRM rating. See Appendix B for more information on beer color.
SizeThe average size of the kernels and the distribution is important to the brewer because it affects how well the malt is crushed by the roller mills. If a significant proportion of the kernels are small, then those kernels will not be crushed well and the extract from the mash and lauter will decrease. Kernel size and distribution are measured by sieving. The ASBC method uses standard sieves with mesh sizes of 7/64”, 6/64”, and 5/64”. Kernels that pass thru the 5/64” sieve are caught in a pan and classified as “thru”. The sum of the percentages captured by the 7/64 and 6/64 sieves is often described on the malt analysis sheet as “% Plump.” Typically, malt is required to have 80 or 90% of the batch be Plump. The percentage that passes thru the 5/64 is often labeled “% Thin,” and the requirement is typically 2% maximum. In Europe and the UK, the sieve sizes are very slightly larger, being: 2.8 mm, 2.5 mm, and 2.2 mm.
ProteinThe protein measurement in malt is actually an approximation, based on chemical analysis of the total amount of nitrogen in a malt sample. Every 1% of nitrogen is assumed to represent 6.25% of protein. You may see Total Nitrogen on an analysis instead of Total Protein.American barley varieties are usually higher in protein than European varieties. The range of protein for 2 row varieties is 11-13% for North American varieties, European and Australian are 9.5-12%. Six row averages a little higher at 12-13.5%. Barley with total protein measuring over 13.5% is not used for malting.
S/T RatioThe Soluble-to-Total-Protein Ratio (S/T ratio), also known as the Kolbach Index, is the most commonly used indicator of malt modification. During the malting process, the proteolytic enzymes in barley cleave the large insoluble proteins into smaller soluble proteins. About 38-45% of the malt protein (as measured by nitrogen as total protein above) is converted to soluble protein, including enzymes, foam-positive proteins and amino acids. The ratio of soluble nitrogen to total nitrogen for the malt describes the extent of unlocking of the endosperm. To generalize, a ratio of 36-40% is a less-modified malt, 40-44% is a well-modified malt, and 44-48% is a highly modified malt. Soluble protein levels below 35% can result in low extraction due to inacessibility of the starch matrix, and difficulty in lautering due to higher beta glucan levels. Soluble protein levels exceeding 55% will lead to excessive darkening during wort boiling, beer haze, and loss of body in the beer. See Chapter 14 for more explanation of malt modification.
Diastatic PowerThe diastatic power of a malt is a measure of the starch conversion capability in degrees Lintner (°L). Diastatic power is measured by evaluating the effects of all the diastatic enzymes in the malt. The diastatic enzymes in malt are degraded by kilning, and thus the diastatic power of highly kilned malts like Munich and Vienna is less than that of lager malt. Malts with DP of 40 or greater are able to convert themselves. Munich typically has a DP of 40-50, Pale Ale malt is about 80. Lager malt generally has a DP of 100-140, and wheat malt and 6 row brewers malt can have a DP as high as 165 °L. High diastatic power is most useful when brewing with starch adjuncts. You can determine the conversion potential of an adjunct mash by calculating the dilution of the enzymatic malts and their diastatic power. In other words, a six row brewers malt could support a dilution ratio of 2/3 adjuncts and still have an equivalent DP of 55 for the mash. The only caveat is that low DP mashes will take longer to convert, and there is the risk that all of the beta amylase will be denatured by the mashing temperature before conversion is finished. See Chapter 14 for more information on starch conversion. (An extensive search of both printed references and the Internet did not reveal just what a Lintner unit consists of. Perhaps named after Carl Lintner 1828-1900, director of the brewing school at Weihenstephan.)
Summary
The malting process allows the grain to partially germinate, making the seed’s resources available to the brewer. Malted barley is the principal source of the sugars that are fermented into beer. From a homebrewer’s point of view, there are basically two kinds of malts, those that need to be mashed and those that don’t. Mashing is the hot water soaking process that provides the right conditions for the enzymes to convert the grain starches into fermentable sugars. The basic light-colored malts such as pilsener malt, pale ale malt, and Munich have sufficient diastatic power to convert their starches into fermentable sugars. Highly kilned malts like Amber and Brown malt do not have significant diastatic power and need to be mashed with base malts.
Specialty malts are non-enzymatic malts that can be divided into two groups, and are used for flavor and coloring. Caramel malts have had their starches converted to sugars by heat and moisture right inside the hull, and can be steeped or mashed. The sugars in caramel malts have a pleasant caramel-like sweetness. The sugars in kilned & roasted malts have bitter chocolate and coffee-like flavors. These malts can also be steeped or mashed.
Lastly, there are non-enzymatic fermentables that are not derived from malted barley, that are called “adjuncts.” Adjuncts include refined sugars, corn, rice, un-malted rye and wheat, and unmalted barley. Adjuncts made from unmalted grains must be mashed with enzymatic malts to convert their starches to fermentable sugars.
In the next chapter, we will steep some specialty malts to make porter.