I think my beer turned into vinegar. How do I know for sure

[Cro Magnon]

I made an Irish red....fermented for two weeks at around 22C using Fermoale AY3. Carbonated to 2.2 vols and let condition for one week. ( It's very warm where I am so 1 week has always given me great carbonation). Refridgerated for a day and just cracked one open. I can definitely get some sour notes. Doesn't taste awful but not great either. And it was hardly carbonated.

What do I do? Dump the whole batch? Let it condition for longer and see if the flavour improves? Is it safe to drink as is? If acetobacter did get in and make vinegar, well there's no remediation for that I guess. All advice greatly appreciated.

 

[VikeMan]

Well if it's actually sour, that would suggest a Pediococcus (lactic acid) , Lactobacillus (lactic acid and possibly acetic acid), or Acetobacter (acetic acid) infection. There's no cure for any of those, other than enjoying as a sour beer. Further (warm) conditioning would likely make it more sour.

 

[Cro Magnon]

Oh no..yes I suspected acetobacter. It's smelling very much like vinegar. You say I can enjoy it as a sour beer, but is it even beer? Doesn't the acetobacter convert all the ethanol into acetic acid? So, do I dump? It's not very enjoyable to drink TBH.

 

[VikeMan]

Doesn't the acetobacter convert all the ethanol into acetic acid?

It needs oxygen for that.

So, do I dump? It's not very enjoyable to drink TBH.

I suppose you could use it to make actual vinegar.

 

[Tobor_8thMan]

Oh, you'd know as there is NO question.

Now, if indeed, this did happen, need to 100% understand why this happened to prevent from happening again.

 

[VikeMan]

Oh, you'd know as there is NO question.

What do you mean by that? The taste threshold for acetic acid is about 60-100 mg/L. Let's say it's 80 for OP. Below 80, he wouldn't taste it at all. At 80, and a little above, it would be very subtle. A little higher, and it would be less subtle. And well above the threshold, it would be obvious.

 

[Tobor_8thMan]

Nope. IMO, vinegar is vinegar. Immediately obvious. I realize we all are different, but to me, vinegar is vinegar.

 

[Dinadan]

To me the smell of vinegar is distinctive. I do not recall ever tasting it. But does beer actually become vinegar? Wine, yes, but I never heard of beer doing that.

 

[VikeMan]

My point is that depending on concentrations, acetic acid (or any flavor compound) will be non-detectable, subtly/ambiguously detectable, or obvious. It's a continuous scale. Nobody has a magic palate that can circumvent this. If you have a lower than average threshold for acetic acid, the scale just moves down.

 

[VikeMan]

But does beer actually become vinegar? Wine, yes, but I never heard of beer doing that.

If you give it oxygen, it can. Some people make vinegar from beer intentionally. It's probably reasonable to say that a beer with acetic acid from an infection is partially vinegar.

 

[Tobor_8thMan]

To me the smell of vinegar is distinctive. I do not recall ever tasting it. But does beer actually become vinegar? Wine, yes, but I never heard of beer doing that.

Depends on the infection. Possible to make beer smelling similar to vinegar.

Astringent
Tastes/Smells Like:
Tart, vinegary, tannin, drying, puckering sensation, may feel powdery or metallic in the mouth, like sucking on a grape skin or a tea bag
Possible Causes:
Astringency can be caused by many different factors. Polyphenols or tannins are the number one cause of such flavors. Tannins are found in the skins or husks of the
grain as well as in the skin of fruit. Steeping grain for too long or grain that has been excessively milled or crushed can release tannins. When mashing, if the pH exceeds 5.2 – 5.6, astringent flavors can be produced. Over-hopping can also lend a hand in creating astringent qualities.
How to Avoid:
Avoid grain that has been “over-milled”. Grain should be cracked open but not crushed or shredded. When sparging, pay close attention to the temperature and the amount of the water used. When steeping grains, be sure to take them out before the water gets to a boil. Fruits should never be boiled in the wort; instead, they can be added to the fermenter or to water that is hot but not boiling for 15-30 minutes. Make sure that the amount and varieties of hops used are the correct types for the style of beer.

Sour/Acidic
Tastes/Smells Like:
Vinegary, acrid, felt on the sides of the tongue towards back of the mouth
Possible Causes:
Extremely sour or vinegary flavors are almost always the result of a bacterial or wild yeast infection. Lambic style beers are beers that have been purposely exposed to
specific types of wild yeast and bacteria to create the unmistakable cidery and sour flavors they are known for.
How to Avoid:
Bacteria and wild yeast are in the air, all around us, all of the time. Commonly referred to as “nasties” in the brewing world, these bacteria and yeast only fall downward – they will not crawl up an in. Make sure to thoroughly sanitize everything and anything that will be coming into contact with beer post boil. Cover your kettle when cooling your wort. Wort or beer that is under 180ºF is prime breeding ground for bacteria and wild yeast. Dirt cannot be sanitized so clean equipment prior to sanitizing if it is visibly dirty. If using a plastic fermenter check it for any scratches, as these are a great place for bacteria to hide. Only open the fermenter when necessary. Use high quality yeast and/or make a yeast starter. The faster the yeast starts to ferment, the more likely they will over power or push out any nasties. Proper sanitation is one of the most important things when it comes to making great home brew!

 

[Hoppy2bmerry]

To me the smell of vinegar is distinctive. I do not recall ever tasting it. But does beer actually become vinegar? Wine, yes, but I never heard of beer doing that.

Malt vinegar is a favorite on fish and chips, of course, there’s no hops andded which would change the flavor, but it would be your own so worth an experiment.

 

[Tobor_8thMan]

My point is that depending on concentrations, acetic acid (or any flavor compound) will be non-detectable, subtly/ambiguously detectable, or obvious. It's a continuous scale. Nobody has a magic palate that can circumvent this. If you have a lower than average threshold for acetic acid, the scale just moves down.

Everyone is different. Ask a friend whom is intolerant to cilantro. Until recently, I had never heard of such a thing.

 

[VikeMan]

Everyone is different. Ask a friend whom is intolerant to cilantro. Until recently, I had never heard of such a thing.

I think you are completely missing my point.

Does every beer taste like vinegar to you? Do you realize that every beer contains some acetic acid?

 

[Tobor_8thMan]

I think you are completely missing my point.

Does every beer taste like vinegar to you? Do you realize that every beer contains some acetic acid?

I'm missing zero point. I realize the components of our brews, but no beer, for the most part tastes like vinegar. If someone thinks all beers taste like vinegar then that's their personal problem. Time to get a helmet, bucket up and deal with their problems.

 

[VikeMan]

I'm missing zero point. I realize the components of our brews, but no beer, for the most part doesn't taste like vinegar. If someone thinks all beers taste like vinegar then that's their personal problem. Time to get a helmet, bucket up and deal with their problems.

So, you can taste vinegar at any level. And all beer has some. But most beers don't taste like vinegar to you. Got it.

 

[Qhrumphf]

Not sure what conversation you think you're having but you're the only one having it.

To the OP, acetobacter is finicky, it's an obligate aerobe IIRC, and unless you're aging beer in a barrel I'd say it's unlikely, especially on this timeframe. A lactic bacteria is possible. My wife thinks lactic acid tastes and smells vinegary. Also possible you're mistaking something else, an ester, acetaldehyde, oxidative compounds, something else that's, giving you the impression of vinegar without actually being acetic acid.

 

[Tobor_8thMan]

Man, you need help if most beer tastes like vinegar. Why even drink beer. Why even here? I'm sure there are some self help group for those "vinegar obsessed beer drinkers".

 

[VikeMan]

Man, you need help if most beer tastes like vinegar.

I haven't said that most beer tastes like vinegar. I recommend re-reading the posts in this thread, carefully, in order. G'night.

 

[Qhrumphf]

Again you're off in the corner talking to yourself.

All beer has acetic acid. That is vinegar. Full stop. All beer has DMS and all beer has diacetyl too. Every single one of em. But they're normally below threshold levels. Which means it can't be tasted.

 

[bracconiere]

(i love it when it comes to blows at HBT!) lol

 

[Cro Magnon]

Wow...I like where this has gone! Interesting, Vike you say all beer has acetic acid....so this means that aceto contamination is inevitable? And the degree to which you taste it is a function of how much the aceto has been allowed to multiply and/or convert ethanol into acetic acid?

Tobor thanks for all the info on the off flavours....It's hard to tell the diff between astringency, acidity and sourness at low levels (for me)....to me right now it smells, more than tastes...distinctly like vinegar.....or like vinegary-wine let's put it like that. It tastes like a 70% beer and 30% vinegar mix. Now whether it's some other off flavour compound giving me the impression of vinegar as you say...I can't know for sure. I have been trying out some new things as part of my process. Would be great to know if any one of these caused this.

1) I squuuuueezed the crap out of the brew bag. Actually until the stuff coming out of it had an oily consistency. But then again I did this for a stout and a hefeweizen before and I never had any off flavours (one would think at least in a hefeweizen it would become obvious).

2) Another thing I learned from another poster on HBT is with regard to wort cooling, cos I don't have a chiller. I pour the wort through a funnel filled with ice and this results in really fast cooling. However, I use sanitary ice (boiled, cooled and put in sanitized ice trays, collected in sanitized collection trays), and the funnel and the vessel I was pouring into were both sanitized...so again...I dunno...

3) When pouring the wort into the fermenter, I strain it through a muslin cloth or handkerchief (both sanitized) but because the hop residue clogs it up so quick...I have to squeeze it towards the end.....but I've sanitized my hands as well.

So I have no clue. But coming back to the off flavours discussion....when wild brewing....other than in intentional inoculation with brett...how does one know if there is additional inoculation with pedio, lacto and aceto? Is this only through the tasting of certain off flavours? Surely there is an overlap between these off flavours making it difficult to identify specifically which organism is causing it. So if mine is lacto infected....do I just let it go for months and see if it starts to get funky, grow mushrooms, unicorns etc? Or do I use this beer to sanitize my toilet bowl?

 

[Cro Magnon]

Not sure what conversation you think you're having but you're the only one having it.

To the OP, acetobacter is finicky, it's an obligate aerobe IIRC, and unless you're aging beer in a barrel I'd say it's unlikely, especially on this timeframe. A lactic bacteria is possible. My wife thinks lactic acid tastes and smells vinegary. Also possible you're mistaking something else, an ester, acetaldehyde, oxidative compounds, something else that's, giving you the impression of vinegar without actually being acetic acid.

Thats an interesting point about your wife perceiving lactic acid to be vinegary. This could be the case with me as well. You mention that aceto is unlikely in this time frame unless I'm aging in barrels etc. Where could the lacto have come from? I've described my process in the post above. Is lacto just everywhere? I opened the fermenter once, the day before bottling....but it already had the smell I'm describing, so I'm guessing the contamination happened somewhere on brew day before I racked to fermenter. Ayyyah...I'm now in constant fear of vinegar... Texas vinegar massacre, Vinegar the 13th, Vinegar 3: Son of Vinegar, I Vinegar on your Grave..

 

[Cro Magnon]

Okayyy I did forget to mention one thing. I think my yeast itself is possibly contaminated. Here's why:

My online LHBS sells only 25gm packets of yeast. I make small batches where I use only 5-6 gms per batch. This happens to be the first batch where I've used a previously opened packet of yeast. I did tape it up and store it in a sanitized ziplock bag in the freezer, but I fear perhaps this wasn't enough. What do you guys think? And any tips on how I can store this dry yeast safely after opening?

 

[VikeMan]

Vike you say all beer has acetic acid....so this means that aceto contamination is inevitable? And the degree to which you taste it is a function of how much the aceto has been allowed to multiply and/or convert ethanol into acetic acid?

All beer has acetic acid, because yeast make it in small amounts. This does not mean that acetobacter contamination is inevitable (or even likely). The degree to which you taste (or not) acetic acid is a function of your own taste threshold and the concentration of acetic acid in the beer.

So I have no clue. But coming back to the off flavours discussion....when wild brewing....other than in intentional inoculation with brett...how does one know if there is additional inoculation with pedio, lacto and aceto? Is this only through the tasting of certain off flavours?

If you simply collect whatever falls into your wort (or other medium) and use it, then you are pretty likely to get a mixed bag of yeast and bacteria. If you don't take this mixed culture and plate/isolate whatever it is you want, then you can only guess what's in it, by the way the pellicle (if any) looks, ropy-ness (or not), aroma, and flavor.

Surely there is an overlap between these off flavours making it difficult to identify specifically which organism is causing it.

There is some overlap. Heavy acetic acid would generally indicate acetobacter. But Lactobacillus can also make acetic acid. (So can Brett and Sacch, but normally not much.) Heavy lactic acid would indicate Lactobacillus or Pedio.

 

[Qhrumphf]

Brett can make a boatload of acetic acid given enough oxygen.

And even in wild brewing, I'd rather keep acetobacter out.

But acetic acid is produced by yeast during the creation of ethanol. And your body (like acetobacter) breaks ethanol back down into acetic acid. All yeast produce it. Not all of it is turned to ethanol. In all but sour beers it should be well below threshold.

 

[Qhrumphf]

Unless your beer was unhopped, lactic bacteria i would also say is unlikely in this timeframe. Most lactic bacteria are very hop-phobic, and the ones that aren't can take a long time to produce significant acid especially when hops are present. The quick workers like L Plantarum will not sour hopped wort.

You mentioned hot temps. I could see a combo of esters, acetaldehyde, and some higher alcohols lending a tart-ish fruitiness lending a character reminiscent of vinegar.

 

[IslandLizard]

3) When pouring the wort into the fermenter, I strain it through a muslin cloth or handkerchief (both sanitized) but because the hop residue clogs it up so quick...I have to squeeze it towards the end.....but I've sanitized my hands as well.

You can sanitize your hands only to a certain degree, so skin contact with chilled wort or beer should be avoided unless you pasteurize (the wort) again, afterward. Maybe wear gloves when squeezing?

On the other hand, there's really no need to strain/filter the (chilled) wort that tightly (finely). Just by letting the chilled wort sit in the (covered) pot for 30 minutes, most trub will have precipitated. Pour or siphon the clear wort on top carefully into your fermenter, leaving the trub (with some wort) behind. Even some trub in your fermenter won't harm your beer. It may be even helpful, and it all precipitates out after fermentation has finished, while it conditions, before packaging (bottling/kegging). Cold crashing generally speeds up precipitation.

That leftover trubby wort can be strained or refined but if touched by skin or other non-sanitary devices, should be re-pasteurized before adding to your batch in the fermenter. I often do that under the paradigm: "No wort left behind!"
From a 5 gallon batch I can reclaim about 2-3 quarts from the trub by straining through tight mesh nylon "hop bags." The reclaimed wort gets then re-pasteurized at 150-160F for 20' or simply reboiled. It can then be added to the main batch (if volume is lowish), fermented on the side in it's own (small) fermenter, used to make syrups, or (yeast) starter wort.

 

[RM-MN]

Brett can make a boatload of acetic acid given enough oxygen.

And even in wild brewing, I'd rather keep acetobacter out.

But acetic acid is produced by yeast during the creation of ethanol. And your body (like acetobacter) breaks ethanol back down into acetic acid. All yeast produce it. Not all of it is turned to ethanol. In all but sour beers it should be well below threshold.

Do some yeasts produce more acetic acid than others? I've had a couple batches have a sour taste that I attributed to the variety of yeast I used. Once I changed back to my normal yeast I quit having that issue.

 

[IslandLizard]

Okayyy I did forget to mention one thing. I think my yeast itself is possibly contaminated. Here's why:

My online LHBS sells only 25gm packets of yeast. I make small batches where I use only 5-6 gms per batch. This happens to be the first batch where I've used a previously opened packet of yeast. I did tape it up and store it in a sanitized ziplock bag in the freezer, but I fear perhaps this wasn't enough. What do you guys think? And any tips on how I can store this dry yeast safely after opening?

You may be onto something there.
But if you're careful and use good sanitation, there's no real danger of infecting the yeast.

Are those 25 gram yeast packets perhaps repackaged themselves? You don't live in the U.S., but yeast here is typically sold in heat sealed foil pouches, by the manufacturer. 5 and 11 gram pouches are most common. I've never seen 25 gram pouches but US-05 is sold in 500 gram bulk packs, like bread yeast.

What sanitizer are you using?