Chapter 2 - Brewing Preparations
2.2.2 Cleaning Your Equipment
Cleaning Plastic
There are basically three kinds of plastic that you will be cleaning: opaque white polypropylene, hard clear polycarbonate and clear soft vinyl tubing. You will often hear the polypropylene referred to as "food grade plastic", though all three of these plastics are. Polypropylene is used for utensils, fermenting buckets and fittings. Polycarbonate is used for racking canes and measuring cups. The vinyl tubing is used for siphons and the like.
The main thing to keep in mind when cleaning plastics is that they may adsorb odors and stains from the cleaning products you use. Dish detergents are your best bet for general cleaning, but scented detergents should be avoided. Bleach is useful for heavy duty cleaning, but the odor can remain and bleach tends to cloud vinyl tubing. Percarbonate cleaners have the benefit of cleaning as well as bleach without the odor and clouding problems.
Dishwashers are a convenient way to clean plastic items providing that the water can get inside. Also, the heat might warp polycarbonate items.
Cleaning Glass
Glass has the advantage of being inert to everything you might use to clean it with. The only considerations are the danger of breakage and the potential for stubborn lime deposits when using bleach and TSP in hard water areas. When it comes to cleaning your glass bottles and carboys, you will probably want to use bottle and carboy brushes so you can effectively clean the insides.
Cleaning Copper
For routine cleaning of copper and other metals, percarbonate-based cleaners like PBW are the best choice. For heavily oxidized conditions, acetic acid is very effective, especially when hot. Acetic acid is available in grocery stores as white distilled vinegar at a standard concentration of 5% acetic acid by volume. It is important to use only white distilled vinegar as opposed to cider or wine vinegar because these other types may contain live acetobacteria cultures, which are the last thing you want in your beer.
Brewers who use immersion wort chillers are always surprised how bright and shiny the chiller is the first time it comes out of the wort. If the chiller wasn't bright and shiny when it went into the wort, guess where the grime and oxides ended up? Yep, in your beer. The oxides of copper are more readily dissolved by the mildly acidic wort than is the copper itself. By cleaning copper tubing with acetic acid once before the first use and rinsing with water immediately after each use, the copper will remain clean with no oxide or wort deposits that could harbor bacteria. Cleaning copper with vinegar should only occasionally be necessary.
The best sanitizer for counterflow wort chillers is Star San'. It is acidic and can be used to clean copper as well as sanitize. Star San can be left in the chiller overnight to soak-clean the inside.
Cleaning and sanitizing copper with bleach solutions is not recommended. The chlorine and hypochlorites in bleach cause oxidation and blackening of copper and brass. If the oxides come in contact with the mildly acidic wort, the oxides will quickly dissolve, possibly exposing yeast to unhealthy levels of copper during fermentation.
Cleaning Brass
Some brewers use brass fittings in conjunction with their wort chillers or other brewing equipment and are concerned about the lead that is present in brass alloys. A solution of two parts white vinegar to one part hydrogen peroxide (common 3% solution) will remove tarnish and surface lead from brass parts when they are soaked for 15 minutes at room temperature. The brass will turn a buttery yellow color as it is cleaned. If the solution starts to turn green, then the parts have been soaking too long and the copper in the brass is beginning to dissolve. The solution has become contaminated and the part should be re-cleaned in a fresh solution.
Cleaning Stainless Steel and Aluminum
For general cleaning, mild detergents or percarbonate-based cleaners are best for steel and aluminum. Bleach should be avoided because the high pH of a bleach solution can cause corrosion of aluminum and to a lessor degree of stainless steel. Do not clean aluminum shiny bright or use bleach to clean an aluminum brewpot because this removes the protective oxides and can result in a metallic taste. This detectable level of aluminum is not hazardous. There is more aluminum in a common antacid tablet than would be present in a batch of beer made in an aluminum pot.
There are oxalic acid based cleansers available at the grocery store that are very effective for cleaning stubborn stains, deposits, and rust from stainless. They also work well for copper. One example is Revere Ware Copper and Stainless Cleanser and another is Kleen King Stainless Steel Cleanser. Use according to the manufacturer's directions and rinse thoroughly with water afterwards.
