Chapter 2 - Brewing Preparations
2.2.3 Sanitizing Your Equipment
Once your equipment is clean, it is time to sanitize it before use. Only items that will contact the wort after the boil need to be sanitized, namely: fermentor, lid, airlock, rubber stopper, yeast starter jar, thermometer, funnel, and siphon. Your bottles will need to be sanitized also, but that can wait until bottling day. There are two very convenient ways to sanitize your equipment: chemical and heat. When using chemical sanitizers, the solution can usually be prepared in the fermentor bucket and all the equipment can be soaked in there. Heat sanitizing methods depend on the type of material being sanitized.
The cheapest and most readily available sanitizing solution is made by adding 1 tablespoon of bleach to 1 gallon of water (4 ml per liter). Let the items soak for 20 minutes, and then drain. Rinsing is supposedly not necessary at this concentration, but many brewers, myself included, rinse with some boiled water anyway to be sure of no off-flavors from the chlorine.
Star San is an acidic sanitizer from the makers of PBW and was developed especially for sanitizing brewing equipment. It requires only 30 seconds of contact time and does not require rinsing. Unlike other no-rinse sanitizers, Star San will not contribute off-flavors at higher than recommended concentrations. The recommended usage is one fluid ounce per 5 gallons of water. The solution can be put in a spray bottle and used as a spray-on sanitizer for glassware or other items that are needed in a hurry. The foam is just as effective as immersion in the solution. Also, the surfactant used in Star San will not affect the head retention of beer like those used in detergents.
Star San is my preferred sanitizer for all usages except those that I can conveniently do in the dishwasher. A solution of Star San has a long usage life and an open bucket of it will remain active for several days. Keeping a solution of Star San in a closed container will increase its shelf life. The viability of the solution can be judged by its clarity; it turns cloudy as the viability diminishes.
One last note on this product: Because it is listed as a sanitizer and bactricide by the FDA and EPA, the container must list disposal warnings that are suitable for pesticides. Do not be alarmed, it is less hazardous to your skin than bleach.
Iodophor is a solution of iodine complexed with a polymer carrier that is very convenient to use. One tablespoon in 5 gallons of water (15ml in 19 l) is all that is needed to sanitize equipment with a two minute soak time. This produces a concentration of 12.5 ppm of titratable iodine. Soaking equipment longer, for 10 minutes, at the same concentration will disinfect surfaces to hospital standards. At 12.5 ppm the solution has a faint brown color that you can use to monitor the solution's viability. If the solution loses its color, it no longer contains enough free iodine to work. There is no advantage to using more than the specified amount of iodophor. In addition to wasting the product, you risk exposing yourself and your beer to excessive amounts of iodine.
Iodophor will stain plastic with long exposures, but that is only a cosmetic problem. The 12.5 ppm concentration does not need to be rinsed, but the item should be allowed to drain before use. Even though the recommended concentration is well below the taste threshold, I rinse everything with a little bit of cooled boiled water to avoid any chance of off-flavors, but that's me.
Heat is one of the few means by which the homebrewer can actually sterilize an item. Why would you need to sterilize an item? Homebrewers that grow and maintain their own yeast cultures want to sterilize their growth media to assure against contamination. When a microorganism is heated at a high enough temperature for a long enough time it is killed. Both dry heat (oven) and steam (autoclave, pressure cooker or dishwasher) can be used for sanitizing.
Dry heat is less effective than steam for sanitizing and sterilizing, but many brewers use it. The best place to do dry heat sterilization is in your oven. To sterilize an item, refer to the following table for temperatures and times required.
Table 3 - Dry Heat Sterilization
12 hours (Overnight)
The times indicated begin when the item has reached the indicated temperature. Although the durations seem long, remember this process kills all microorganisms, not just most as in sanitizing. To be sterilized, items need to be heat-proof at the given temperatures. Glass and metal items are prime candidates for heat sterilization.
Some homebrewers bake their bottles using this method and thus always have a supply of clean sterile bottles. The opening of the bottle can be covered with a piece of aluminum foil prior to heating to prevent contamination after cooling and during storage. They will remain sterile indefinitely if kept wrapped.
One note of caution: bottles made of soda lime glass are much more susceptible to thermal shock and breakage than those made of borosilicate glass and should be heated and cooled slowly (e.g. 5 °F per minute). You can assume all beer bottles are made of soda lime glass and that any glassware that says Pyrex or Kimax is made of borosilicate.
Autoclaves, Pressure Cookers and Dishwashers
Typically when we talk about using steam we are referring to the use of an autoclave or pressure cooker. These devices use steam under pressure to sterilize items. Because steam conducts heat more efficiently, the cycle time for such devices is much shorter than when using dry heat. The typical amount of time it takes to sterilize a piece of equipment in an autoclave or pressure cooker is 20 minutes at 257° F (125 °C) at 20 pounds per square inch (psi).
Dishwashers can be used to sanitize, as opposed to sterilize, most of your brewing equipment, you just need to be careful that you don't warp any plastic items. The steam from the drying cycle will effectively sanitize all surfaces. Bottles and other equipment with narrow openings should be pre-cleaned. Run the equipment through the full wash cycle without using any detergent or rinse agent. Dishwasher Rinse Agents will destroy the head retention on your glassware. If you pour a beer with carbonation and no head, this might be the cause.
Cleaning and Sanitizing Bottles
Table 4 - Cleaning and Sanitizing Summary Table
Dishwashers are great for cleaning the outside of bottles and heat sanitizing, but will not clean the insides effectively. If your bottles are dirty or moldy, soak them in a mild bleach solution or sodium percarbonate type cleaners (ex. PBW) for a day or two to soften the residue. You'll still need to scrub them thoroughly with a bottle brush to remove any stuck residue. To eliminate the need to scrub bottles in the future, rinse them thoroughly after each use.
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It is important to use unscented detergents that won't leave any perfumey odors behind. Be sure to rinse well.
1/4 cup per 5 gallons
(<1 Tbs per gallon)
Best all purpose cleaner for grunge on all brewing equipment. Most effective in warm water.
1 tablespoon per gallon.
Effective cleaner for grungy brewing deposits. Will not harm metals.
1 - 4 tablespoons per gallon.
Good cleaner for grungy brewing deposits.
Do not allow bleach to contact metals for more than an hour. Corrosion may occur.
1 tablespoon per gallon.
Good cleaner for grungy brewing deposits.
May often be found in paint and hardware stores.
Prolonged exposure times may cause mineral deposits.
Normal amount of automatic dishwater detergent
Recommended for utensils and glassware. Do not use scented detergents or those with rinse agents.
Follow product instructions.
Often the only way to dissolve burned-on sugar from a brewpot.
White Distilled Vinegar
Full Strength as necessary. Most effective when hot.
Useful for cleaning copper wort chillers. Cleansers made for Stainless Steel and Copper pots and pans are also useful.
2:1 volume ratio
of vinegar to peroxide
Use for removing surface lead and cleaning brass.
Oxalic Acid based
As Needed with Scrubby
Use for removing stains and oxides.
Table 5 - Sanitizers
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2 tablespoons per 5 gallons
Can be used via immersion or spraying. Will sanitize clean surfaces in 30 seconds. Allow to drain before use; does not need to be rinsed.
12.5 - 25 ppm
1 tablespoon per 5 gallons = 12.5 ppm.
Iodophor will sanitize in 10 minutes at 12.5 ppm and does not need to be rinsed. Allow to drain before use.
1 tablespoon per gallon.
Bleach will sanitize equipment in 20 minutes. It does not have to be rinsed, but probably should be to prevent chlorophenol flavors.
Full wash and Heat Dry cycle without detergent.
Bottles must be clean before being put in dishwasher for sanitizing. Place upside down on rack.
340°F for 1 hour
Renders bottles sterile, not just sanitized. Allow bottles to cool slowly to prevent thermal shock and cracking.
Clean all equipment as soon after use as possible. This means rinsing out the fermentor, tubing, etc. as soon as they are used. It is very easy to get distracted and come back to find that the syrup or yeast has dried hard as a rock and the equipment is stained. If you are pressed for time, keep a large container of water handy and just toss things in to soak until you can clean them later.
You can use different methods of cleaning and sanitizing for different types of equipment. You will need to decide which methods work best for you in your brewery. Good preparation will make each of the brewing processes easier and more successful.