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.