There are several options to consider when choosing a cleaning/sanitizing regiment for your home brewery.
This tutorial will provide a basic introduction to the most popular methods of cleaning/sanitizing, with advantages, and disadvantages of each option.
Firstly, the terms cleaning and sanitizing should never be lumped together. They are two separate, unique processes that accomplish different goals. With that being said, this author does not encourage the use of any type of dual cleaner/sanitizer chemical that is available to homebrewers. (And there are many).
In order to achieve proper sanitization levels within your brewery setting, cleaning is the first, and most vital step.
The chemicals used for killing the microbial organisms work by reacting with their cell walls. So if you have a hard to reach spot in your equipment that is coated in dirty deposits, chances are, that the grime is harboring some amount of micro organism contamination that your sanitizer cannot get to.
So, what are the best methods to remove this soiling? The answer is as varied as styles of beer, but here are the most common methods:
1) PBW (Powdered Brewery Wash) is a non-caustic alkali professional grade brewery equipment cleaner with surfactants and chelating agents (removes hard minerals). This type of cleaner is the greatest choice if it is handy. PBW removes organic soiling quickly and easily, and rinses clean. Soaking in PBW solution works well to clean heavily soiled items.
Concentration: 1 oz in 1 gal water (30mL/4L) for heavy washing. 1/2 to 3/4oz per gal for soaking, or light washing.
Storage: Solution can be stored in glass and plastic. I store some in my rinsed fermenters right after racking the beer off, so they are ready to be rinsed and sanitized right away, on the next brew day.
2) Acid cleaners: Removes inorganic soiling from hard minerals. Best for removing 'beer stone' deposits, but not an effective cleaner for heavy organic soiling.
3) Dish Detergent: Foamy surfactant. This cleaner works by emulsifying and rinsing organic residues away. Since it does not have alkali, so it does not actually break down the organic soiling. Rinsing time is therefore greater than with alkali based cleaners. Soaking time for heavily soiled items will have minimal effect, requiring more mechanical scrubbing.
4) Oxyclean: Alkali based cleaner (sodium percarbonate). Works by saponification (chemically changing the grime to make it rinse away) of organic residue. This is more effective than dish detergent, but does not include surfactant. Soaking and rinsing works better than detergent based cleaners, but the oxygen cleaning property will be depleted quickly.
Storage: Solution can be stored in glass. Since it contains perfumes, storage in plastic containers is not recommended.
Now that your equipment is thoroughly cleaned, and rinsed, you are ready to sanitize. Sanitization is the process of killing off unwanted micro organisms to a manageable level. This term is not to be confused with sterilization, which is the total destruction of all micro organisms on the surface.
Here are the most common methods of effective sanitizing in your brewery:
1) Bleach: A halogen (chlorine) based sanitizer with a high pH (about 12). 30 min contact time is required. Rinse withboiled water thoroughly to avoid off flavours getting into your beer. Bleach is the cheapest solution for homebrewing sanitization, but the disadvantages of extended contact time, and the requirement to rinse with sterilized water, are a big put off.
Concentration: 2 oz in 5 gal water.
Storage: Need about 50ppm to be effective. The chlorine volatizes quickly out of solution, so storage is not recommended. Chlorine test strips can be purchased from pool stores.
2) Iodophor: A halogen (iodine) based, low foaming, no rinse sanitizer, which offers no off tastes when mixed in the proper amounts. 1 minute contact time is sufficient for a sanitizing kill level. Iodophor mixes to a light brown/orange solution, which lets you know it's there. This property also can stain plastic equipment, which is entirely an aesthetic issue, however.
Concentration: 1oz in 5gal cold or lukewarm water provides 25ppm of titratable iodine.
Some useful conversions:
- 30mL in 19L water
- 1 Tablespoon in 10L water
- 1 Teaspoon in 3L water
- 5mL in 3L water
- 1 capful of the 4oz bottle sized cap in 3L water
- 3 capfuls in 10L water
Storage: Iodophor solution dissipates over time (though not as fast as bleach), so storage for more than a day is not advisable. If the solution is still light brown, then it is probably still effective.
3) Star San: A high foaming, acid anionic, no-rinse sanitizer, which offers no off tastes when mixed in the proper amounts. 1 minute contact time is sufficient for a sanitizing kill level. The foam is a put off for some people, though the chemical breaks down into what is essentially yeast nutrient in your brew.
Concentration: 1 oz/5 gal cold, or luke warm water.
Storage: If DI or distilled water is used to make a solution of Star San, then it can be stored for long periods of time, and will remain active. I keep a filled spray bottle by my kegarator at all times. If the solution becomes cloudy, discard.
A word about chemical concentrations
Increasing the concentration past the recommended levels can have several disadvantages. Firstly, it can take you out of no rinse category, which can effect your brew or your health.
Further, many of the chemicals used in homebrewing, are designed to hit a certain pH or concentration value. Changing the concentration, may therefore reduce the optimal activity of the chemical.
Lastly, excessive use of these chemicals simply costs us MONEY!
I hope this introductory article has helped clarify some basic issues with regards to common cleaning and sanitizing practices that are most applicable to the home brewer.
There certainly is no BEST method out there, but keeping in mind the proper cleaning and sanitizing procedures, mixing concentrations, and safety protocols, will allow every brewers method to be equally as effective.