rexbanner said:
Not to be a dick, but I scrubbed the **** out of all my plastic buckets the first few times I brewed. 3 years later, I'm using the same buckets and have never had a single infection in nearly 40 batches. I've heard this same story before, and it almost caused me to replace my buckets, but if it ain't broke...
What did you scrub it with? And what kind of beers did you make? Scratches would definitely create an issue, although the people who say it needs to be thrown out after 5-6, or 8-10, or however many uses are off their rocker, as far as I'm concerned.
One great thing about beer, is that it is often harder to infect than many people realize. I just opened my first bottle today of a bigger and even hoppier version of Pliny the Elder. I used leaf hops in a 4gal kettle at the time, and it caused so many problems and was clogging up everything, to the point where I just got a nylon mesh dryhop bag (literally as big as the bucket itself, and stretches around the sides) and dumped the wort/hops in it. Very little wort came out as the hops had absorbed it all, and I was so frustrated at that point, that, not even rinsing my hands, I just grabbed the bag squeezed all the wort right out of the hops, with all the wort flowing slowly over my hands.
10 weeks later, and the beer tastes amazing, despite being so exposed to bacteria that the only thing I could probably have done worse is spit in it. But the gigantic starter I made definitely helped by letting the yeast get a quick start on eventually producing 11% ABV, and as a IIPA, the antibacterial properties of the hops doubtlessly played a role as well. Had I done the same with an English mild, I probably wouldn't have been so lucky.
But if you ARE creating scratches in the fermentor, it's only a matter of time - each beer made in it is only going to create more bacteria in it, and cleaners/sanitizers can't properly tackle that. Keep in mind, even tiny scratches are like the grand canyon to those little critters, and they can grow to pretty significant numbers just in the shelter it provides. Eventually, there are enough of them in numerous scratches in the bucket, and you make a weaker beer, or use a yeast that gets a particularly slow start, and they gain a decent foothold. And once the beer is infected, it's no problem for them to cram into every single microscopic nook and cranny that the beer contacts, and that is why it's a really bad idea to re-use plastic equipment once it's been used with infected beer.
What you're scrubbing with also makes a difference. Some things aren't as bad as others, and if you stop scrubbing with something after only a few times, you'll probably get away with it - though I would probably repurpose a bucket for grain storage or something if I saw visible scratches somewhere that is in contact with beer. But, for example, using a carboy scrubber (meant for glass) on a Better Bottle or plastic bucket is much more likely to create problems than a rag/washcloth, and a soft sponge is a lot better than using the abrasive side of a sponge.
In the OP's case, it's impossible to be certain about how the original owner cleaned and in general treated the equipment, or if it's even been used with infected batches. In his case, especially considering the way the equipment seems to have been treated, it's impossible to tell if it ain't broke or if it is, and it would suck for a new brewer to waste time and money, and more importantly, be discouraged because some asshat was offloading his infected equipment on Craigslist or something instead of throwing it out.