First Time Brewer - Sour Taste

[Aristotelian]

I am just getting started in brewing. Don't really know what I am doing and can use some help. The problem is I am getting a strong sour taste after two weeks fermentation. Looks and smells like beer, but a very strong vinegar taste. I am brewing 1 gallon batches using a Belgian Caramel Wit kit. Partial mash, primary fermentation only, going straight into bottles for conditioning.

First batch came out OK after 10 days fermentation and 3 weeks in bottles. A little on the sweet side and carbonation was inconsistent but otherwise OK.

Second batch, decided to try fermenting longer, went to 12 days. Everything looked good. Decided to put it in bottles after no visible activity for a week. This is when I got the first sour taste. I read that this could be a normal part of the process so I went ahead and bottled. They have been conditioning for over two weeks and the sour taste is still there.

Third batch has been fermenting 13 days. Decided to taste a small sample before bottling and the vinegar taste is back.

I read that this could be a normal byproduct and to keep fermenting, so I have added a pinch of sugar and pinch of yeast a few minutes ago. Activity is starting back up. Is this worth continuing or should I dump it?

Looking closely at my equipment, I am worried I have not been filling the airlock with enough water. Could that be the cause?

I'd appreciate any ideas for rescuing this batch and/or avoiding the issue in the future.

 

[Sammy86]

Well I'm just gonna say it for the veteran Brewers here...what was your recipe? What kind of yeast? What temp are you fermenting at? What kind of water are you using?

Details help to allow people to help you!

As for dumping it I wouldn't! There is a great thread I can't find right now by I believe Revvy where he left a bottle of beer that had an off taste from what I remember a year and it was beautiful...time is your friend unless it is an infection.

Anyway, more details and I'm sure a bunch of people will jump in to help!

 

[VT-NAV]

Does it taste sour sort of like vinegar does, or does it taste like actual vinegar?

If it's just sour in general, it is probably due to some sort of bacterial contamination, but it could have other causes.

If it tastes like actual vinegar, you definitely have bacterial contamination - specifically, a type of acetobacter.

I suspect you need to improve your sanitation practices. Once you've sanitized something, try to avoid contaminating it at all costs. I've no idea if you used an actual "pinch" of sugar and yeast, but if you use your hands to regularly manipulate your post-boil ingredients, then that is likely the source of your infection. Hands, even washed hands, are generally very filthy in the context of contaminating your brew, so try to never touch anything that will contact your beer without first being boiled.

In addition to improving future sanitation practices, I also recommend you do a deep-clean of all your equipment. I'd use a mild bleach solution on all non-stainless steel equipment. I don't normally recommend bleach as it is sort of the nuke-it-from-orbit option; however, in this case it is essential that you annihilate all the bacterial contamination on your equipment.

 

[Aristotelian]

Does it taste sour sort of like vinegar does, or does it taste like actual vinegar?

Yes, I would say the dominant taste is vinegar. It taste like vinegar with a beer aftertaste rather than beer with a vinegar aftertaste. However, no visible fungus, streaks, etc.

So...toss?

I will definitely work on sanitation. Thanks for the advice.

 

[Aristotelian]

By the way, "pinch" was not literal. I was getting ready to bottle, so sugar was dissolved in boiling water. Yeast was added directly from the packet.

Could the contamination be from the airlock being set up improperly? I think it may not have been filled up with enough water.

 

[Clonefan94]

By the way, "pinch" was not literal. I was getting ready to bottle, so sugar was dissolved in boiling water. Yeast was added directly from the packet.

Could the contamination be from the airlock being set up improperly? I think it may not have been filled up with enough water.

Possibly, but more than likely it's something that wasn't sanitized well enough. I say that, because once the yeast kick in, it's pretty tough to contaminate the beer at that time. You usually have enough CO2 going out that it prevents anything from getting in, even if the airlock isn't functioning quite right. I know of people who've had lids blow off during fermentation that had no issues with contamination.

Airlocks are most helpful after fermentation is complete, to keep anything from getting in when you have no offgassing of CO2.

Although, you did say "not have been filled up with enough water." I don't ever use water in my airlocks. I usually use cheap vodka or starsan to fill up my airlocks. WAter can harbor bacteria, that if you get any suckback it could pull that bacteria with the water. So, the water in the airlock could have been an issue.

 

[VT-NAV]

Sorry if that "don't touch things with your hands" came off as patronizing. This is the beginner's forum and you never know some times...

The way I interpret the problem, your first batch came out just fine, but the second and third batches got progressively worse.

I suspect your equipment was not fully cleaned and sanitized after the first batch. A little bacterial colony formed between the first and second batches, and grew larger between the second and third. In a case like this where there is massive acetobacter infection (and it would have to be pretty bad to convert ethanol to vinegar that quickly), it's usually the tubing or autosiphon housing the bacteria colony that's getting in the beer.

In any event, I'd recommend you hit the fermenter, tubing, and autosiphon with a strong bleach solution (2 tablespoons bleach per gallon of water) for twenty minutes - just make sure you rinse thoroughly afterwards.

Acetobacter is commonly carried by fruit flies. If your airlock was close to empty, it's entirely possible some fruit flies got into the fermenter. It's also possible that some fruit flies got into the wort as it was cooling. If you cooled the wort with the kitchen sink ice bath method that's commonly recommended to beginners, then it's very possible a few fruit flies buzzing around contaminated the wort. Sink drains are notorious breeding grounds for fruit flies. If you ever observe any fruit flies around your brewing space, it's best to postpone brewing until you can eliminate the fly problem.

 

[Aristotelian]

Interesting, we do get fruit flies at this time of year and I do remember seeing some buzzing around the carboy even though I had it in a spot outside of the kitchen (although I did not see any sign of them inside the carboy).

I don't think it is the tubing because I transfer the wort with a sanitized funnel, and it turned sour before before bottling. Never went through the tubing (although now the tubing is probably contaminated).

I will toss the last two batches and try again in the fall with everything sanitized.

Would it be a good idea to try a shorter fermentation period, 10 days or so like the first batch?

 

[flars]

What are you using for cleaning your equipment? What sanitizer are you using? Air locks are best when filled with strong alcohol or a sanitizer like Starsan solution.

Are you using glass carboys or plastic buckets? When you take a sample for a specific gravity reading, do you sanitize the top of the fermentor and the equipment for drawing a sample?

Fermentation is complete when the specific gravity remains stable. My beers will be in the fermentor for at least three weeks.

 

[Aristotelian]

I just wanted to update the thread and thank the forum for the advice. I brewed a new batch a couple weeks ago, paying much closer attention to sanitizing, including sanitized water in the airlock. (Probably should have been common sense but none of the instructions I was using said that explicitly and that may have been the problem). Anyway, I tasted a sample before bottling last night and it is much better! Also did not notice any fruit flies this time.