Monday, March 12, 2012


Sanitation is everything in homebrewing. I don't know how many times I have 'politely' explained to new brewers that just using hot water, One-Step, and their favorite scrubby pad isn't going to kill all the contaminates hiding in their carboy and fermenting buckets. You would think that for as often as new brewers complain how their beer tastes like crap - or ask why they have a "harmless white film" growing on top of their fermenter - that they would realize their sanitation procedure might just have something do with it. However, considering the number of homebrewers that are seemingly content drinking infected beer, proper sanitation still has a long ways to go. StarSan and Idophor are cheap and easy enough to use, that everyone who dabbles in homebrewing should be using them.

I am normally obsessive to a "T" about cleanliness and proper sanitation, but I do screw up on occasion. Case in point, my latest batch of Scottish "session" ale or 70/-. This batch got off to a good start, I sanitized the heck out of all my equipment and didn't expose the fermenting beer to any possible contaminates. And unlike some people, I try to avoid peeking into the bucket or taking a hydrometer sample each and every day. However, I made a crucial mistake with this batch. Instead of spending an extra few minutes to fill the airlock with vodka or StarSan, like I normally do, I was lazy and just filled it with tap water. I wasn't worried about suck-back. Well, fast forward three weeks later. I went to move the fermenter and sure enough I accidently hit the lid with my arm... draining the airlock liquid back into the beer. **** ~ ! Hoping that nothing bad would come of it, I let the beer sit another week. I was greeted with this awful sight a few days later...

It really pisses me off to think that all my hard work, time, and money was completely wasted because I was too lazy to walk up the stairs and grab the vodak. (Quite possibly the only time in history when bad things happened because someone DIDN'T use the vodka!). Six hours of brewing and three weeks of fermenting undone in an instant. From the looks and smell of it, I believe I have some type of lacto infection going on. It is sorta interesting that the infection is growing on top of the krausen, never seen that before. I tired a small sample of the beer and it tasted pretty good for the state it was in. Had I not screwed this beer up, I'd probably be enjoying a few pints of it from the cask by now. In the hope of salvaging some of my investment, I racked two gallons of the infected beer into a large glass jug and pitched a whole bunch of Russian River and Jolly Pumpkin sour dregs. If the beer shows any promise within a month or two, I'll keep it around. 

A few obvious 'pointers' for keeping your beer infection free:

1) Sanitize, sanitize, and sanitize. Use a good stanitizer - not just a cleanser - and make sure that everything and anything that touches the beer has been adequately treated. This means your racking cane, bucket, carboy, lid, spoons, ect...

2) Try to avoid exposing the fermenting beer to the elments. This includes the time it takes to cool and transfer your wort from the brew kettle. The fewer times you open the lid on the fermenting beer, for whatever reason, the better. Don't take excessive hydrometer samples. I've gotten to the point where I take one when the beer goes into the fermenter and one when it comes out. Until then, the beer lid/carboy plug stays closed.

3) Keep a fresh spray bottle of sanitizing liquid on hand. And remember, change out the liquid frequently. If using Star San, distilled water is best and Idophor doesn't have a long shelf life when mixed. Some breweries change out their sanitizer a few times over the course of the brew-day. 

4) Throw out or don't use any plastic materials with deep scratches. Change your plastic tubing regularly.

Lastly, while many people seem to think that beer infections are hard to get - or that many signs of an infection are just normal fermentation activity - they might be surprised to know that most infections go unnoticed. Generally speaking, any white film that covers the surface of the beer and breaks up into smaller pieces when agitated, is indicative of an infection. It's not "hop oils" or "sanitizer residue" or whatever else you want to believe it is. This picture below is of a slight lacto infection in a keg. Yeah, hard to believe, considering it shows very little signs of something wrong. It may even look somewhat normal. However, when we tested it in the lab, the results indicated otherwise.

The key here, is that not all infections result in terrible tasting beer. Most homebrew does contain bacteria, mold, and other stuff that never fully impacts the overall character of the beer. But it is better to know that it is in our beer and be able to recognize it, than just assume a beer is only truly infected when the surface looks like a murder scene. 


  1. That sucks...i'm surprised you got that kind of visible infection from the water in your airlock. It shouldn't be that prone to infection 3 weeks in after the alcohol levels are pretty much final. If that was the case, dry hopping should be a major risk but it doesn't seem to be. Also, the pellicle formed within a week of infection? Unless it was cloudy, rancid water the pitch rate is going to be pretty small. It just doesn't seem plausible that the airlock water is the cause. In any case, bubble airlocks are great when using plastic fermenters. Maybe Vancouver doesn't have as many nasty bugs floating around because so far I've been lucky (looks for wood to knock on). I did a wort stability test a few batches ago - I let it sit beside the fermenter for 3 weeks and it didn't ferment (still clear and it still tasted sweet).

    1. It was probably a combination of factors in addition to the suck back - cheap plastic bucket that I normally don't use, very low gravity/hopping, and I let it sit for over a month as I brewed it on 5 March. Could have been scratches in plastic too, though I didn't notice anything unusual until after the water got sucked in. Whatever exactly caused it, I can't say. However, I have seen fruit flies get caught in my airlocks before (though with vodka) that could have be a possibility...?

  2. Well, bad luck I must say. I've made some beers during my life and few times there was a suckback. I always use the tap water... cheap plastic buckets - never with any visible signs of infection (visual and during tasting)

  3. The distilled water with star san tip was one I'd not heard before. Makes sense, especially with the local water. Thanks.

  4. Sucks about the infection. But it is true; all beer has bacteria in it - sanitizer is sanitizer at best - not sterilizer. It gets 'bugs' to negligible levels, not zero. They're there, and the pitched yeast ususally win the war, but there are variables that cause the airborne/dormant surface-harbored bugs to multiply to noticeable levels, even if the pitched yeast win. And sometimes the pitched yeast still loose

    During fermentation I've been using santized 3 piece airlocks with no bubbler - reduces head pressure on the yeast, which reduces stress. CO2 they create is heavier than air, so once fermentation has started, no air is going down anyhow, barring extreme change in temp or something? I do add the bubbler piece and santizer after 4-5 days when fermentation has slowed.

    A lot of people emphasize santitization without realizing that a hardcore cleaning beforehand is just as important. Stained buckets should eventually be tossed. Even nice looking buckets should be cleaned 'chemically' to remove organic deposits with an intense alkaline solution such as washing soda, sodium percarbonate, or best yet a PBW soak - which will can also help loosen scale-based deposits that can harbor bacteria.

    Certain situations just make equipment santitization moot - like plastic that gets beyond the point of return (which is a bit of a grey area), and/or anything porous that has held or contacted lacto/brett cultures...those are best considered permanently infected and used only for a repeat fermentation with the same culture, if at all...

    It all comes down to risk and just how risky you are willing to be. Most people take a few steps back after an infected fermentation, which usually happens after they took one too many steps away from best practices.

    1. I don't remember the exact numbers, but one of the big homebrew clubs put out a piece on C02 production for 5 gallon batches and determined that the amount of top pressure caused by the C02 was so little it did not impact the fermentation. I used to do a lot of open fermentation, thinking the top pressure in the carboy would suppress esters, but the science says this isn't so. Still need to check it out a bit more tho.

      I ended up retiring all of my plastic buckets. Most were a few years old and I needn't take the risk again. However, funny enough the 'infected' beer that I racked into the jugs w/out dregs looks and tastes pretty good. No pellicle or anything. I'm not saying it wasn't infected, but the brunt of the infection may have on top of the krausen. We'll see in a month or so.

  5. Hey Will,

    Why don't you ditch the airlock and lid. Just use cling film to cover your fermenter. Use the rubber o-ring from the lid to hold the cling film on and from now on no more suck-back. Very popular method down here in Australia. CO2 easily escapes and as a side benefit you can keep an eye on krausen.

  6. LOLOLOLOL. My favorite part about this is how you describe how you are normally so careful. I don't understand that part. Are you explaining that this shouldn't happen to you? Are you saying that LOOK it can even happen to someone like me? I'm unsure what that adds at all to this saying you normally are so careful. If you screwed up you screwed up. It makes no sense giving an intro like you did. Because there are people I personally know who NEVER clean their stuff and NEVER get infections. So it works the opposite way as well. This was a bizarre article to say the least. It's like a guy who normally gets straight As goes out and parties all night the night before the final and then says, hey, give me a break I normally get straight As. Um, so what! Or the guy who is normally a great husband who beats his wife one night. What you've done in the past no impact on your current screw up.


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