Knights of the Mashing Fork

CLEAN AND SANITARY

by Michael Froehlich, Homebrewer at Large or a Large Homebrewer

Hello all! Today's lesson focuses on cleaning and sanitizing bottles, carboys, other fermentation vessels, and any equipment that comes in contact with cooled wort. Cleaning and sanitizing processes are completely different. You can have one without the other. A surface can be cleaned of dirt and grime but there still may be active bacteria present and likewise, a surface can be heat sanitized but there may be an inert chemical residue that can screw up your beer. For better brewing, both cleaning and sanitizing must be part of your brewing process. Even though it is the most unpleasant, it is the most important.

I would like to start out by explaining the differences between the terms: clean, sanitary, and sterile. A clean surface is free of dirt, grime, or other gore. It is easy to clean a surface but cleaning doesn't mean sanitizing.

Sanitization is generally thought of as killing the more sensitive vegetative cells but not heat-resistant spores. Sanitization does not necessarily include sterilization, although some processes of sanitization accomplish sterilization.

Sterilization means the freeing of any object or substance from all life of any kind, this includes heat resistant spores. For microbiological purposes microorganisms may be killed in situ (In place) by heat, gases (such as formaldehyde, ethylene oxide, or B-propiolactone), solutions of various chemicals, or ultraviolet or gamma irradiation.

The primary methods of cleaning for a homebrewer are:

  • TSP - Tri Sodium Phosphate
  • Bleach
  • B-Brite
  • Strong acid or caustic solution
  • Scrub like a mad dog
TSP is a favorite for cleaning because it is great at reducing odors and built-up gunk on previously used fermentation vessels. It is also relatively inexpensive. Problems with TSP include: It's hard to find real TSP (they removed the phosphate agent in the TSP brand--the one in the orange box--available at the grocery store. Look for real TSP in Home Depot's paint section); it produces a hard- to-remove white film on equipment that is soaked for a long time in a strong solution; and, lastly, it may cause possible environmental disposal concerns. To use TSP correctly, use about 1-2 tablespoons per gallon of water, and rinse well after cleaning.

Bleach is effective in cleaning and sanitizing and is very inexpensive. Use unscented bleach; the cheapest brand will work fine. Problems with bleach include: it turns clothing white fast; it requires a thorough rinsing after cleaning (bleach contains chlorine, and chlorine compounds don't make the greatest beers); it's more harmful to the environment than TSP (don't water lawn with bleach water = dead grass); it's very corrosive to stainless steel (maximum time in contact less than 2 hours); and, finally, it's not as effective at reducing odors. Use 1 tablespoon per gallon of water. Soak equipment at least 20 minutes for effective sanitization, and rinse well with water or cheap beer.

B-Brite is very effective in cleaning and sanitizing, but it does cost more than TSP and bleach. B-Brite has the active ingredient, Sodium Percarbonate. This is a mixture of sodium carbonate and hydrogen peroxide. The sodium carbonate is for cleaning and the hydrogen peroxide (H2O2) provides the sanitization. The sanitizing time for B-Brite is 15 minutes. B-Brite is also very effective at reducing odors and is not environmentally damaging. Use as directed.

Strong acid or caustic solutions are very dangerous to use and are not recommended for the average homebrewer. However, for cleaning out a counterflow wort chiller (clean every 5 batches or so), run a solution of 1 teaspoon of Red Devil (a commonly available drain cleaner) and 1 gallon of warm water through your wort chiller. Then flush the solution down a toilet. Be sure to rinse thoroughly.

Scrubbing like a mad dog will work at cleaning surfaces, but you will not be able to reduce odors/gunk to levels that will not affect your beer without some type of chemical solution. Get comfortable with using chemicals, and remember that properly used chemicals are not harmful to the environment.

The following are the preferred methods of sanitizing:

  • Bleach
  • B-Brite
  • Iodophor
  • Dry heat, steam, or hot solutions (Actually, using these methods you can effectively achieve sterilization.)

As you may noticed, bleach and B-Brite are common to both areas. These chemicals were discussed above.

Iodophor is very effective at sanitizing a clean surface. A solution of 1 tablespoon in 5 gallons of cold water--never use hot-- will sanitize equipment in 2 minutes. Remove equipment and let air dry. Equipment is now ready for use. No need to rinse surface. Great stuff, but it's also more expensive than bleach. There is another benefit besides the short contact time: As long as the solution is amber colored, there's sufficient iodine present to sanitize.

Dry heat, steam, or hot solutions are also very effective at sterilizing surfaces. Pure heat (i.e., flame or radiative heat from an oven) can be used only with metal or glass. Glass bottles can be effectively sterilized by placing clean bottles in an oven with aluminum foil over bottle opening (wet bottles work great; steam is very effective), setting oven to 250 degrees F., letting them bake for 30 minutes (once the temperature has stabilized), and then turning off the oven and allowing the bottles to cool slowly. Boiling wort or water can sterilize very well and has been used on hoses (watch type of hosing, make sure it's heat resistant to 210 degrees F) and wort chillers.

As you can see, there are many methods to clean, sanitize, and even sterilize brewing equipment, and new methods are invented everyday. All methods require patience and understanding in order to be effective. If you are careful with your cleaning and sanitizing procedures, your beers will always taste "clean," i.e., there'll be no off-flavors that can be attributed to infections from poorly cleaned and sanitized equipment.


Definitions:

Sanitization:
Sanitization is generally thought of as killing the more sensitive vegetative cells but not heat-resistant spores. Sanitization does not necessarily include sterilization, although some processes of sanitization accomplish sterilization. Sanitization is usually accomplished by chemicals such as phenol, formaldehyde, chlorine, iodine, or bichloride of mercury.
Sterilization:
In microbiology, sterilization means the freeing of any object or substance from all life of any kind, this includes spores. For microbiological purposes microorganisms may be killed in situ by heat, gases (such as formaldehyde, ethylene oxide, or B-propiolactone), solutions of various chemicals, or ultraviolet or gamma irradiation. Sterilization can also be accomplished through mechanical means, such as filtration and centrifugation.

Michael Froehlich, froeh@thor.naa.rockwell.com 12/16/94
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