Q&A Session at Meeting - Sanitation

[ChriStovall]

Starting a thread to provide additional info from our Q&A Session at our regular SBL meeting. At the last meeting, there was a tech talk on sanitation. There was a great amount of back & forth on the topic. Below is info from our BJCP class that may provide additional information. Feel free to add add'l points. I'm thinking this will be a good thing to add each month to the forum as a depository for information and a platform for additional discussion.

Face It. You can’t stop all microorganisms from getting into your beer. There are a myriad of bacteria and wild yeast everywhere in the environment (air, kitchen counter, floor, and your uncleaned unsanitized brewing equipment). However, by properly cleaning and sanitizing your equipment , you can eliminate major causes of contamination or a least reduce to negligible levels where their growth will not appreciably affect the beer and brew beer free of off-flavors and off-aromas produced by non-brewing organisms.

Bacteria
About the time (late 1860’s) Louis Pasteur discovered yeast caused fermentation of beer, he also discovered that bacteria and/or wild yeasts could spoil beer. Furthermore, he found that large amounts of healthy yeast could overcome relatively small amounts of bacteria to prevent spoilage, thus limiting (not eliminating) bacteria was the key.

There are many types of bacteria, but only a few are encountered in brewing due to high alcohol & low pH making an inhospitable environment for them, and no pathogenic bacteria can survive in beer (so you won’t die or get sick from drinking a beer – well, at least appropriate amounts of beer – tainted with bacteria, but tainted beer is crappy beer all the same). Bacteria are typically categorized by whether they are stained by gentian violet (Gram Stain).
• Gram Positive bacteria include Pediococcus and Lactobacillus, which form lactic acid bacteria that operate anaerobically, ferment simple sugars and have a big impact on protein. Pediococcus produces turbidity, undersirable taste & odor, and acetic acid. Lactobacillus produce sourness and turbidity, but no odor. They typically show up as ropy or gelatinous slime on top of your primary fermenter. Lactobacillus delbruckii metabolizes glucose and yields lactic acid without the other by-products and can be brought out by an extended acid rest of 95 º but care must be taken that it not become overactive in the mash and over-sour. It is used in Berliner weisse to promote the sourness of the style. Gram-positive bacteria are inhibited by isohumulones from the hops and do not typically survive in very bitter wort or beer.
• Gram negative bacteria come from coliforms. Clostridium butyricum (butyric acid bacteria) are thick anaerobic rods that putrefy the mash by forming rancid-smelling ethylactic acid active below 112º. Acetic acid bacteria taint mashes below 122 º giving sour-fruit vinegary taste & odor. Coliform bacteria (such as Escherichia Coli) contribute cooked or spoiled vegetable, sulfury odors, typically coming from unboiled tap water and produce during lag phase. Hafnia strains produce sourness and smell like parsnips or celery but do not survive in acidic conditions. Zymomonas anaerobia come from ground water & produce banana or rotten egg odor.

Three Levels of “Clean”
Clean: Free of dirt, grime or other grub (where bacteria can harbor) – does not mean sanitary.
Sanitized: the killing of sensitive vegetative cells but not heat-resistant spores – still not sterilized. Can’t sanitize without being clean first, though. “Disinfected” is a legal/regulatory term for sanitized, meaning that a product will sanitize within 10 min.
Sterile: eliminating all life of any kind. This can be accomplished through heat, gas, chemical solutions or irradiation.
**All homebrewers typically need to do is properly clean and sanitize. Sterilization is overkill.
Basically if it’s going to touch the wort after its cooled, it needs to be sanitized. Beforehand, clean is typically fine.


Methods of Cleaning
Detergent – use unscented mild varieties for general cleanup (Ivory or similar). Make sure no additives that may leave a residue. Make sure to rinse thoroughly (“squeaky clean”).
TSP – TriSodium Phosphate – reduces odors and built-up gunk, cheap. Available in paint section at hardware store. Phosphates are an environmental concern. 1-2 tbsp per gallon and rinse well.
Bleach – cleans and sanitizes, very cheap. 5.25% Sodium Hypochlorite solution. Unscented, generic is best. Forms caustic solution in cold water good for breaking up deposits. Must be thoroughly rinsed afterward and can leave odor on plastic, corrosive to stainless steel >2hrs. Copper & brass will blacken through oxidation. 1 tbsp per gallon for 20 minutes to sanitize. Is volatile and will lose effectiveness within a few days at diluted state.
Sodium Percarbonate - (sodium carbonate – which is becoming the base for many laundry detergents & hydrogen peroxide active ingredient). B-Brite, OxyClean, PBW are all brand names. Cleans and sanitizes, though best to use a separate sanitizer with it. More expensive than bleach or TSP. Reduces odors well and not environmentally damaging. Good for plastic, glass and metal. 1 tbspn per gallon. Claims 15 minutes to sanitize. PBW is good for beer stone allowed to soak for 4 hours, then rinse w/ acid wash or CLR. One-Step is another brand name that combines acids to clean and sanitize.
Strong Acid or Caustic Solution – Acetic acid (white distilled vinegar – 5% per volume) is an effective cleaner for copper and can help clean stainless (don’t use cider or wine vinegar). Stronger acids and caustic solutions are dangerous. Very hazardous to skin/eyes and can be toxic. Sodium hydroxide (lye) can be used with proper protective gear (goggles, gloves) but not recommended. Oven cleaner or drain cleaner is a slightly diluted form. Use on stubborn scorched-on spots on brewpots. Spray on and rinse thoroughly with some vinegar and rinse again. Lye is very corrosive to aluminum and brass but o.k. on copper & st. steel (as long as not heated).
Dishwashers – due to small openings in bottles, cleaning doesn’t necessarily occur. Using for heat sanitizing is a good use, though. Go through full wash and heat dry cycle with no detergents or additives (Jet Dry).

Methods of Sanitizing
Bleach, Percarbonates, Dishwasher
Iodophor – iodine with polymer – keeps amount of free iodine low that makes it safe to handle. Very effective at sanitizing a clean surface. Solution of 1 tbspn to 5 gallons (12.5 ppm) of cold water (never hot) will sanitize in 2 minutes. Hospital grade in 10 minutes. No rinse when used at proper concentrations. If water is amber, sufficient iodine present. Very stable in pure form but degrades over time in water mixture (tho more stable than chlorine). Stains plastic.
Dry/Moist Heat – can’t use dry heat (oven) with most plastics. Bake for 60 minutes at 338 degrees or 12 hours at 250 degrees to sterilize. Some say 30 minutes at 250 will sanitize – wet bottles work great (steam). Boiling water good for glass, metal and some hoses. Autoclave/pressure cooker use heat and pressure in moist environment to sterilize – 20 minutes @ 257F @ 20 psi.
Alcohol – limited use in brewing (ironically) & actually not sure how it works – either by denaturing cell proteins or interfering with cellular metabolism. 70% alch/water mixture best. Typically less than 5 minutes, but 10 min. recommended. Does not kill bacterial spores or viruses (except after long exposure). Flammable. Best use is for yeast culturing equipment/bottles. Isopropyl (rubbing) and methyl alcohols are more effective sanitizers, but toxic and give off-flavors. Ethyl is best used for drinking – while sanitizing with a different method.
StarSan is an acid mixture (phosphoric/sulfonic & isopropyl alch) – 30 seconds to sanitize – opens cell walls and ruptures. 1 oz. per 5 gallons. No rinse (inactive above pH=3.5).

Methods of Sterilization
Dry/Moist Heat a la autoclave
Chemicals/gases: formaldehyde, ethylene oxide, or B-propiolactone
Ultrviolet or Gamma Irradiation
Mechanical: filtration and centrifugation





Reads: http://www.beer-brewing.com/brewery_cle ... tation.htm ;
http://www.brewery.org/brewery/library/sanitize.html ;
http://www.franklinbrew.org/brewinfo/sanitation.html
http://www.howtobrew.com

[mtripka]

Let me be the first........

NO, NADA, NYET,

DO NOT USE BLEACH.

[FJRussoNC]

Outstanding Job. Congrats.

[srmatt]

Ditto on the presentation.

I used bleach to brighten up a dingy fermenter recently, mostly because I'm too cheap to spring for another. Several ounces in a fermenter full of water allowed to sit with lid on for an hour or two does it. Rinse, rinse, rinse, wipe dry, air dry, then 'sniff test'. If you smell it much at all rinse again and air dry. It's a good method if you think you have bugs infecting your fermenters because it will kill anything. Keep in mind that plastic will absorb any type of cleaner if soaked too long. One of the very best sanitation techniques is to wash things well with an appropriate cleaner and air dry in the sun, letting the UV do it's thing. You will always sanitize just prior to use, of course.

[dplittle]

I used bleach to brighten up a dingy fermenter recently, mostly because I'm too cheap to spring for another.

I've gotten fond of OxiClean as a poor man's PBW to clean stubborn stains. I use it to clean carboys too. After fermentation I put a scoop in the carboy and fill it to the very top with warm water. A day of soaking and everything just rinses away. I haven't had to use my carboy brush in a long time. Just make sure you get OxiClean Free which doesn't have any dyes or fragrances.