The Sanitation Department

Keeping spoilage at bay

carboy filled with starsan s and a carboy cleaning brush

If cleaning is the act of eliminating soils, sanitation is the act of “eliminating” spoilage organisms (e.g., unwanted yeasts, Brettanomyces, Lactobacillus – anything other than our desired microbes – usually a single strain of Saccharomyces c.). For non-mixed culture brewing practices, we treat otherwise useful creatures as “weeds” — a.k.a., plants growing perchance where we don’t want them.

That second eliminating is in quotes for a reason. In an ideal world, we’d eliminate every last trace of spoilage mechanisms. We would suffer no Brettanomyces, Lactobacillus, Pediococcus, etc. to live. But that would be sterilization and true sterilization is impractical and generally out of reach for almost all brewing operations. Sterilization is good and achievable for lab work and the surgical suite, but for general brewing purposes, we can work with the less perfect and less demanding world of sanitation.

Side Note: One place homebrewers can practice “sterilization” is pressure canning starter wort. Drew’s a big fan of prepping gallons of wort into jars and running them through a pressure cooker at 15 psi for 15 minutes. The end result is growth media that’s as clean of bacteria and fungi as possible in a home setup.

The simplest thing you can do in terms of sanitation is nothing. Clean your fermenters well, pitch a massive quantity of fresh, happy, healthy yeast and stand back. “If it worked for our ancestors for millennia, then it’ll work for me.” You might be tempted to just add plenty of yeast and hope for the best, but please don’t roll the dice when there is no need to risk bad beer. We know about microbes and molecular structures — things our brewing ancestors didn’t.

Sanitation via Heat

Heat kills a lot of things. Boiling is, in fact, our primary sanitizer of wort (a.k.a., the reason we don’t use things like metabisulfite like wine and cider makers). Steam can be used to sanitize appropriate materials.

To be clear — heat should not be used to sanitize your hoses, glass carboys, plastic buckets or your washers. In a lab, there’s a whole slew of things that can be heat sanitized in an autoclave (a fancy version of a pressure cooker — and exactly what Drew was talking about with his starters). In Drew’s whole brewing career, the most effective thing to be boil sanitized were metal Sanke kegs being used as fermenters. Remove any and all pressure retaining devices, add a bit of reverse osmosis (RO)/distilled/deionized water, heat the keg and cap the opening with foil – instant sanitized keg ready for wort.

As a safety reminder: Steam is very, very dangerous. Steam under pressure is basically a bomb. Note in the keg example, Drew’s friends cover the keg opening with foil to avoid any pressure buildup or vacuum (on the cool down). Do not mess with steam unless you know what you’re doing. Also, follow our rule of no drinking while brewing!

In general, don’t use steam – use the stuff we’re about to talk about! Now that we’ve gotten through the tactics we don’t recommend, but if we hadn’t included would have been asked about.

Better brewing through chemistry

By far and away the easiest way to sanitize at home is through the judicious use of chemicals. Judicious in terms of dosage, action, and treatment. Just like with cleaning — too much of a compound is no more effective than the right amount. When we covered cleaning, we looked at items that dissolved chemical bonds and proteins. In sanitation, we’re typically looking at ways to kill bacteria by breaking cell walls. Violent, yes, but have you tasted an infected beer?

Of the sanitation chemicals we’ve used on the regular and going from cheapest to most expensive:

Bleach — sodium hypochlorite

It’s cheap, you can buy it at the local supermarket or corner bodega. It’s supremely effective. What’s not to love? Turns out that human palates are sensitive to chlorine flavors and aromas and bleach packs a punch. Used on its own at the rate of 1–2 oz. per gallon of water (8–16 mL per L), sanitation occurs in as little as one minute of contact with the surface. After that, you have to rinse and let air dry. The rinse should be done with boiled water lest you add bacteria back to your newly microbe barren landscape.

So why pay $$ for other compounds? Consistency of efficacy (is your bleach old and less effective?), lower risk of flavor impact, and chlorine is corrosive to stainless steel with prolonged exposure.

That’s what happens with bleach on its own. We haven’t played with a method recommended by Five Star Chemical’s Charlie Talley that promises to make bleach into a cheap and affordable no-rinse sanitizer: Into 5 gallons (19 L) of water mix 1 oz. (30 mL) of bleach and 1 oz. (30 mL) of white vinegar for a no-rinse, cheap sanitizer (don’t use on stainless steel). 

Warning – follow safe chemical practice and mix the bleach and vinegar into the water. Don’t mix the bleach and vinegar together first and then add it to the water.

The theory is that using bleach in a lower pH medium makes the chlorine more effective and thus allows you to use a lower overall concentration. The quicker action and the lower concentration pushes below the level of concern in terms of taste and lingering impacts.


When you were a kid, your mom may have reached for a stinging bottle of iodine to clean a scraped knee — the pain meant it was working. Iodophor is a combination of iodine, a surfactant for easier mixing and an acid (usually phosphoric). Note that iodine is in the same chemical family as other potent sanitizers like chlorine and fluorine.

Iodophor works quickly (~60 seconds) and when mixed at the proper concentration of 12.5 ppm (typically ½ oz. per 5 gallons/15 mL per 19 L of water) is rinse-free. It’s cheap as chips and is broadly effective. There are some concerns about how well it works against biofilms, but you cleaned the heck out of your surfaces, right? Ergo, that should not be a concern.

Unlike bleach, you won’t find iodophor in the grocery store but it is available through many homebrew stores. Also, iodophor is used across multiple food handling industries, so make sure the stuff you use is suitable for brewing. 

You may have heard that iodophor stains and when you see the yellowish solution floating in front of you, it’s easy to believe it. But with proper dilution levels and appropriate contact times, the staining and potential odor inclusion from iodophor is minimal. Particularly with iodophor, higher doses aren’t beneficial! And as long as the solution is yellow or a test strip gives the thumbs up — iodophor remains effective. 

Acid Sanitizer

Acid-based sanitizers use food-grade and homebrewer-safe acids to kill our unwanted microbes. They’re safe for hands and for beer with virtually no chance of “accidentally” contaminating the beer with off-flavors at any reasonable level of overdoing the concentration.

The biggest name in this game, as far as homebrewers are concerned, is Five Star Chemicals with their Star San. Easy to use and with lightning quick contact times, Star San also adds surfactants and a foaming agent to create bubbles that help ensure contact and complete wetting of the surface. (If the surface doesn’t get wet for a sufficient period of time, you’re not knocking out the bad guys.) The foaming properties are so dramatic and homebrewers worried enough that a motto has ensued – “Don’t Fear the Foam!” 

But if you use a system with a pump, the foam can actually get in the way. Big foam snakes are cool and all, but pumps usually prefer to move liquid around. If you want the acid-based goodness without the foam, Five Star has a product, Saniclean, which is effectively Star San without the foaming agent. It requires slightly more contact time and the onus is now on you to ensure you’ve gotten everywhere wet enough for long enough to ensure microbe murder. 

Both Five Star products will remain effective as long as the pH remains below 3. When mixed with distilled or RO water, that can be quite a while and allow you to really extend the timespan of efficacy for your sanitizer solution.


There are scads of different products at the homebrew level that your local homebrew shop might carry, but these are the ones we’ve played with. In the wine world metabisulfites are the primary sanitizing agent. At the professional level there are other compounds like Quats (Quaternary Ammonium) and PAA (Peroxyacetic Acid) that are regularly used. We haven’t seen much of these at the homebrew level as, like caustic in the cleaning discussion, they require more care when used.

One other thing we didn’t mention – each of these compounds has different strengths and weaknesses. Acid-based sanitizers, for instance, are less effective against mold where iodophor tends to be weaker where biofilms are involved. But for our general use case of “sanitize this surface I’ve thoroughly cleaned” — they all do the trick.

Mechanical Aids and Process

Just like when we talked cleaning, there are ways to make your sanitation duties easier. We’ve addressed concentration previously. Hot temperatures (which do a cleaner good) are generally a no-no with sanitizers as the compounds are generally meant to be used cold at the homebrew level. But agitation is again your friend! If you have a submersible pump or a keg/carboy cleaner — you can easily create a device that ensures your fluids are moving and getting all over those surfaces. 

If you’re frugally minded and want to use the minimum product needed, homebrewers can fill a spray bottle with a sanitizing solution and use it to soak surfaces. For Drew, he’ll do this for things like spigots, valves, hose connections at the last moment, but he still prefers soaking a complete vessel.

Issue: January-February 2023