# SDMB Brewers: name that contaminant! **URL:** \ **Category:** Cafe Society\ **Created:** [April 16, 2007, 7:52pm UTC](https://boards.straightdope.com/t/sdmb-brewers-name-that-contaminant/400377 "2007-04-16T19:52:27Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![capybara](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/capybara/32/202_2.png) [@capybara](https://boards.straightdope.com/u/capybara)\ **Post date:** [April 16, 2007, 7:52pm UTC](https://boards.straightdope.com/t/sdmb-brewers-name-that-contaminant/400377/1 "2007-04-16T19:52:27Z")
Ok, having a problem. This happened with several batches last year, but this year (different apartment but closeby) we’ve been ok until now, until the last batch. Sanitation: pretty good. Working from extracts with a tad of grain for flavor steeped first. Water filtered through carbon. Additives: Irish moss. 3/4 c dextrose for priming. Now, everything goes fine through primary and secondary, but then! Something happens at bottling (24 oz bottles, sanitized with one-step). A tart or sour taste enters (not particularly cabbagey, band-aidy, or sulphery, more like off-citrus?), which gets increasingly strong the longer it’s in the bottle. Doesn’t carbonate well, either. Any thoughts? The troubleshooting in my beer books doesn’t list anything exactly like this. ---
**Author:** ![WarmNPrickly](https://avatars.discourse-cdn.com/v4/letter/w/d78d45/32.png) [@WarmNPrickly](https://boards.straightdope.com/u/WarmNPrickly)\ **Post date:** [April 16, 2007, 9:14pm UTC](https://boards.straightdope.com/t/sdmb-brewers-name-that-contaminant/400377/2 "2007-04-16T21:14:50Z")
Don’t know what it is but I know what to do about it. Relabel it as a lambic and get snoby when people complain that its sour. They’ll think your a pro. ---
**Author:** ![Gatopescado](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/gatopescado/32/5711_2.png) [@Gatopescado](https://boards.straightdope.com/u/Gatopescado)\ **Post date:** [April 16, 2007, 9:20pm UTC](https://boards.straightdope.com/t/sdmb-brewers-name-that-contaminant/400377/3 "2007-04-16T21:20:56Z")
[QUOTE=Christopher] Don’t know what it is but I know what to do about it. [/QUOTE] Me too, or Me neither. Use a generous heap of MaltoDextrin in the boil, dry-hop big in the secondary, use cornsugar to bottle. Never have a tart brew again. ---
**Author:** ![WarmNPrickly](https://avatars.discourse-cdn.com/v4/letter/w/d78d45/32.png) [@WarmNPrickly](https://boards.straightdope.com/u/WarmNPrickly)\ **Post date:** [April 16, 2007, 9:23pm UTC](https://boards.straightdope.com/t/sdmb-brewers-name-that-contaminant/400377/4 "2007-04-16T21:23:15Z")
Computer fart. Double post ---
**Author:** ![Balance](https://avatars.discourse-cdn.com/v4/letter/b/ccd318/32.png) [@Balance](https://boards.straightdope.com/u/Balance)\ **Post date:** [April 16, 2007, 9:35pm UTC](https://boards.straightdope.com/t/sdmb-brewers-name-that-contaminant/400377/5 "2007-04-16T21:35:14Z")
I would guess that your brew is suffering from a bacterial infection–possibly acetobacter, which produces acetic acid. If so, the brew will start developing a vinegar flavor. If it’s not a vinegary sourness, it might be lactobacillus, or any number of other bacteria. Here’s a [nifty quick-reference on Beer Faults](http://www.bjcp.org/faults.html) I stumbled across. It doesn’t specify particular types of infection or how to check for them, though. I don’t know if there’s anything you can do about your current brew except, as **Christopher** said, relabel it :). The best course for the future is probably to be really fanatical about sanitizing all of your brewing equipment. Disclaimer: I neither brew nor drink beer–I make mead and wine, mostly. ---
**Author:** ![silenus](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/silenus/32/166_2.png) [@silenus](https://boards.straightdope.com/u/silenus)\ **Post date:** [April 16, 2007, 9:37pm UTC](https://boards.straightdope.com/t/sdmb-brewers-name-that-contaminant/400377/6 "2007-04-16T21:37:57Z")
Yep. A citrus-y taste is a sign of bacterial infection. Check your hoses and general sanitation procedures. Replace all airlocks and stoppers. Examine secondaries for scratches, replace as needed. Dump the batch and bottles. ---
**Author:** ![capybara](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/capybara/32/202_2.png) [@capybara](https://boards.straightdope.com/u/capybara)\ **Post date:** [April 16, 2007, 10:22pm UTC](https://boards.straightdope.com/t/sdmb-brewers-name-that-contaminant/400377/7 "2007-04-16T22:22:21Z")
Alas. Ok, I’m sort of thinking that lactobacillus is a good option, because it does remind me of the lambic tart more than anything (and I recall that it’s added purposefully to some of those?) (I wonder if I’ve spent so much time drinking the stuff in Belgium that lactobacillus and Bruxellensis yeast exudes from my pores? Rodenbach’s one of my favorite beers… .). So sad. ---
**Author:** ![silenus](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/silenus/32/166_2.png) [@silenus](https://boards.straightdope.com/u/silenus)\ **Post date:** [April 16, 2007, 10:40pm UTC](https://boards.straightdope.com/t/sdmb-brewers-name-that-contaminant/400377/8 "2007-04-16T22:40:19Z")
Consider yourself lucky. The one time my equipment got contaminated it was by a slime mold, which turned 2 batches into something resembling 10W-30, and about as appetizing. I had to totally replace my whole system (well, everything post-boil.) I didn’t trust any of it. ---
**Author:** ![Qadgop\_the\_Mercotan](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/qadgop_the_mercotan/32/83_2.png) [@Qadgop\_the\_Mercotan](https://boards.straightdope.com/u/Qadgop_the_Mercotan)\ **Post date:** [April 16, 2007, 10:44pm UTC](https://boards.straightdope.com/t/sdmb-brewers-name-that-contaminant/400377/9 "2007-04-16T22:44:31Z")
Paging **August West**. ---
**Author:** ![silenus](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/silenus/32/166_2.png) [@silenus](https://boards.straightdope.com/u/silenus)\ **Post date:** [April 16, 2007, 10:50pm UTC](https://boards.straightdope.com/t/sdmb-brewers-name-that-contaminant/400377/10 "2007-04-16T22:50:52Z")
What, you don’t trust my credentials as a homebrewer? I’m BJCP Certified, I am! 😃 ---
**Author:** ![Mike\_Fun](https://avatars.discourse-cdn.com/v4/letter/m/a9adbd/32.png) [@Mike\_Fun](https://boards.straightdope.com/u/Mike_Fun)\ **Post date:** [April 16, 2007, 10:53pm UTC](https://boards.straightdope.com/t/sdmb-brewers-name-that-contaminant/400377/11 "2007-04-16T22:53:04Z")
Tart like a green apple? It could actually be the cornsugar used at bottling. Try using extra light dry extract instead, I’ve been having better luck with this instead. ---
**Author:** ![Qadgop\_the\_Mercotan](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/qadgop_the_mercotan/32/83_2.png) [@Qadgop\_the\_Mercotan](https://boards.straightdope.com/u/Qadgop_the_Mercotan)\ **Post date:** [April 17, 2007, 12:04am UTC](https://boards.straightdope.com/t/sdmb-brewers-name-that-contaminant/400377/12 "2007-04-17T00:04:28Z")
[QUOTE=silenus] What, you don’t trust my credentials as a homebrewer? I’m BJCP Certified, I am! 😃 [/QUOTE] I know, but **Augie** is a homie of mine, and works in the industry. Gotta give him his chance for input! You don’t rely on me only, do you? I always like to have **karlGauss** and **Doc\_Paprika** and **DoctorJ** chiming in too! ---
**Author:** ![butler1850](https://avatars.discourse-cdn.com/v4/letter/b/779978/32.png) [@butler1850](https://boards.straightdope.com/u/butler1850)\ **Post date:** [April 17, 2007, 4:03pm UTC](https://boards.straightdope.com/t/sdmb-brewers-name-that-contaminant/400377/13 "2007-04-17T16:03:53Z")
How are you adding the priming sugar? Are you adding to some water, and bringing to a boil (then cooling) prior to adding to the bottling bucket? If not, you may be introducing an infection via the corn sugar. Sanitation - there is no “pretty good.” There is do, or do not. \ Get a good sanitizer and do it right. (You’re using one step, are you using the correct concentrations?) ---
**Author:** ![August\_West](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/august_west/32/18069_2.png) [@August\_West](https://boards.straightdope.com/u/August_West)\ **Post date:** [April 17, 2007, 4:25pm UTC](https://boards.straightdope.com/t/sdmb-brewers-name-that-contaminant/400377/14 "2007-04-17T16:25:51Z")
Hello! My advice is always the same when it comes to identifying spoilage organisms. It doesn’t matter. To expand on that, it doesnt matter what the spoiler is, the mere presence of a spoiler indicates a breakdown somewhere in your sanitation procedure. All of the steps **silenus** laid out are a good start. Since it only seems to be appearing in the bottles I would tear apart your bottling system and re-examine your bottle sterilizing technique. ---
**Author:** ![capybara](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/capybara/32/202_2.png) [@capybara](https://boards.straightdope.com/u/capybara)\ **Post date:** [April 17, 2007, 7:29pm UTC](https://boards.straightdope.com/t/sdmb-brewers-name-that-contaminant/400377/15 "2007-04-17T19:29:39Z")
I suspect I’m not using enough of the one-step. It occurs now to me that the problem only happens when _I_ and not my spouse cleans the bottles. . . Me: “How much of that stuff do you use?” Him: “A shitload.” I don’t think I use a shitload. So I look on the thing for suggested concentrations and think again about how much a liter is and how much a teaspoon is and think “Oh. Hell.” ---
**Author:** ![Mike\_Fun](https://avatars.discourse-cdn.com/v4/letter/m/a9adbd/32.png) [@Mike\_Fun](https://boards.straightdope.com/u/Mike_Fun)\ **Post date:** [April 18, 2007, 12:47am UTC](https://boards.straightdope.com/t/sdmb-brewers-name-that-contaminant/400377/16 "2007-04-18T00:47:23Z")
So what’s everyone else currently brewing? I’ve got: a “Fin du Monde” clone aging in the bottle for about a month so far a blueberry wheat in the secondary; should be ready for kegging in 2 weeks or so and a “Fat Tire” clone in the primary that was brewed on Sunday. There was a light ale after the Trippel and before the wheat ale, but it was kegged and already consumed! ---
**Author:** ![capybara](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/capybara/32/202_2.png) [@capybara](https://boards.straightdope.com/u/capybara)\ **Post date:** [April 18, 2007, 1:54am UTC](https://boards.straightdope.com/t/sdmb-brewers-name-that-contaminant/400377/17 "2007-04-18T01:54:08Z")
I have another batch-- a wheat-- ready to head into secondary. I’ll be more careful with the bottles this time. . . ---
**Author:** ![WarmNPrickly](https://avatars.discourse-cdn.com/v4/letter/w/d78d45/32.png) [@WarmNPrickly](https://boards.straightdope.com/u/WarmNPrickly)\ **Post date:** [April 18, 2007, 2:29am UTC](https://boards.straightdope.com/t/sdmb-brewers-name-that-contaminant/400377/18 "2007-04-18T02:29:52Z")
> [@](#): > > My advice is always the same when it comes to identifying spoilage organisms. It doesn’t matter. It matters to me. I love lambics, and intend to add these little beasties on purpose. If I were you I would let it sour a bit longer, maybe a full year. Yum yum. ---
**Author:** ![August\_West](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/august_west/32/18069_2.png) [@August\_West](https://boards.straightdope.com/u/August_West)\ **Post date:** [April 18, 2007, 1:33pm UTC](https://boards.straightdope.com/t/sdmb-brewers-name-that-contaminant/400377/19 "2007-04-18T13:33:59Z")
**Christopher** , I wouldn’t be so sure that the spoilage organism in **capybara** ’s beer is going to make a nice tart gueze. It could just as easily turn into big ropy strands of slime. Just calling any contaminated homebrew a “lambic” is an old joke in homebrewing circles, but it does a bit of disservice to the style. ---
**Author:** ![silenus](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/silenus/32/166_2.png) [@silenus](https://boards.straightdope.com/u/silenus)\ **Post date:** [April 18, 2007, 2:01pm UTC](https://boards.straightdope.com/t/sdmb-brewers-name-that-contaminant/400377/20 "2007-04-18T14:01:17Z")
For a good lambic you really need all the cultures. _Brettanomyces bruxellensis_ in particular. [Next page](https://boards.straightdope.com/t/sdmb-brewers-name-that-contaminant/400377.md?page=2)