Cleaning requires a certain amount of scrubbing, brushing and elbow grease. It is necessary because a dirty surface can never be a completely sanitized one. Grungy deposits can harbor bacteria that will ultimately contaminate your beer. The ability of a sanitizing agent to kill bacteria is reduced by the presence of any extra organic matter, so prior cleaning is necessary to assure complete sanitization. Several cleaning products available to the homebrewer are discussed below. Cleaning recommendations for the equipment you will be using follow.
Dish and laundry detergents and cleansers should be used with caution when cleaning your brewing equipment. These products often contain perfumes that can be adsorbed onto plastic equipment and released back into the beer. In addition, some detergents and cleansers do not rinse completely and often leave behind a film that can be tasted in the beer. Several rinses with hot water may be necessary to remove all traces of the detergent. Detergents containing phosphates generally rinse more easily than those without, but because phosphates are pollutants, they are slowly being phased out. A mild unscented dish washing detergent like Ivory is a good choice for most of your routine equipment cleaning needs. Only stubborn stains or burnt-on deposits will require something stronger.
Bleach is one of the most versatile cleaners available to the homebrewer. When dissolved in cold water, it forms a caustic solution that is good at breaking up organic deposits like food stains and brewing gunk. Bleach is an aqueous solution of chlorine, chlorides and hypochlorites. These chemical agents all contribute to bleach's bactericidal and cleaning powers, but are also corrosive to a number of metals used in brewing equipment. Bleach should not be used for cleaning brass and copper because it causes blackening and excessive corrosion. Bleach can be used to clean stainless steel, but you need to be careful to prevent corrosion and pitting.
There are a few simple guidelines to keep in mind when using bleach to clean stainless steel.
- Do not leave the metal in contact with chlorinated water for extended periods of time (no more than an hour).
- Fill vessels completely so corrosion does not occur at the waterline.
- After the cleaning or sanitizing treatment, rinse the item with boiled water and dry the item completely.
Sodium percarbonate is sodium carbonate (i.e. Arm and Hammer Super Washing Soda) reacted with hydrogen peroxide and it is a very effective cleaner for all types of brewing equipment. It rinses easily. Several products (e.g. Straight-A, Powder Brewery Wash, B-Brite, and One-Step) are approved by the FDA as cleaners in food-manufacturing facilities. One-Step is labeled as a light cleaner and final rinse agent, and produces hydrogen peroxide in solution. Hydrogen peroxide will effectively sanitize surfaces and containers that are already clean. As with all sanitizers, the effectiveness of hydrogen peroxide as a sanitizing agent is comprimised by organic soil. Use these cleaners according to the manufacturer's instructions, but generally use one tablespoon per gallon (4 ml per liter) and rinse after cleaning.
In my opinion, percarbonate-based cleaners are the best choice for equipment cleaning, and Straight-A from Logic Inc., and Powder Brewery Wash (PBW) from Five Star Chemicals, Inc. are the best of them. These products combine sodium metasilicate with the percarbonate in a stable form which increases its effectivity and prevents the corrosion of metals like copper and aluminum that strong alkaline solutions can cause.
Trisodium phosphate (TSP) and chlorinated TSP (CTSP) are very effective cleaners for post-fermentation brewing deposits and the chlorinated form is also a sanitizer. TSP and CTSP are becoming harder to find, but are still available at hardware stores in the paint section. (Painters use it for washing walls because it can be rinsed away completely.) The recommended usage is one tablespoon per gallon of hot water. Solutions of TSP and CTSP should not be left to soak for more than an hour because a white mineral film can sometimes deposit on glass and metal which requires an acid (vinegar) solution to remove. This is not usually a problem however.
Using dishwashers to clean equipment and bottles is a popular idea among homebrewers but there are a few limitations:
- The narrow openings of hoses, racking canes and bottles usually prevent the water jets and detergent from effectively cleaning inside.
- If detergent does get inside these items, there is no guarantee that it will get rinsed out again.
- Dishwasher drying additives (Jet Dry, for example) can ruin the head retention of beer. Drying additives work by putting a chemical film on the items that allows them to be fully wetted by the water so droplets don't form; preventing spots. The wetting action destabilizes the proteins that form the bubbles.
With the exceptions of spoons, measuring cups and wide mouth jars, it is probably best to only use automatic dishwashers for heat sanitizing, not cleaning. Heat sanitizing is discussed later in this chapter.
Commonly known as lye, sodium hydroxide (NaOH) is the caustic main ingredient of most heavy-duty cleaners like oven and drain cleaner. Potassium hydroxide (KOH) is also commonly used. Even in moderate concentrations, these chemicals are very hazardous to skin and should only be used when wearing rubber gloves and goggle-type eye protection. Vinegar is useful for neutralizing sodium hydroxide that gets on your skin, but if sodium hydroxide gets in your eyes it could cause severe burns or blindness. Spray-on oven cleaner is the safest and most convenient way to use sodium hydroxide. Brewers often scorch the bottoms of their brewpots resulting in a black, burned wort area that is difficult to remove for fear of scouring a hole in the pot. The easiest solution is to apply oven cleaner and allow it to dissolve the stain. After the burned-on area has been removed, it is important to thoroughly rinse the area of any oven cleaner residue to prevent subsequent corrosion of the metal.
Sodium hydroxide is very corrosive to aluminum and brass. Copper and stainless steel are generally resistant. Pure sodium hydroxide should not be used to clean aluminum brewpots because the high pH causes the dissolution of the protective oxides, and a subsequent batch of beer might have a metallic taste. Oven cleaner should not affect aluminum adversely if it is used properly.