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

[Cro Magnon]

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.

Thanks a lot....I just cannot put my finger on it....All my previous beers were done under the same conditions....something just went off with this. The beer was hopped at 18 IBUs as well.

 

[Cro Magnon]

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.



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.



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.

Thanks...I did not know that yeast produces acetic acid! So, it's not necessarily a contamination then. I saw no other signs of contamination (not that there needs to be any visible signs for there to be an infection, I know) Could temperature fluctuations do this? Because I store it in my room with the airconditioner at 22-23C, but then I turn it off for a good portion of the day as well. This didn't affect my past beers but then each one reacts differently.

 

[Cro Magnon]

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?

Hmmm yes this is seeming suspect now. Thing is, the LHBS sells them under the names of well known strains (like S-04) but they ARE repackaged...they are sealed, vacuumed foil packets though (with no branding). I don't know how this works though...do they buy it in bulk from like fermentis for e.g and then repackage it? Is this a thing?

I've been using Iodophor. I previously just used betadine diluted in water and had no trouble. This is my first batch using iodophor (not that I'm blaming the iodophor).

 

[IslandLizard]

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).

Brew bag?
Are you referring to your mash bag? If so, squeezing that bag is fine, and since it's pre-boil, infection is not an issue at that point.

 

[VikeMan]

Thanks...I did not know that yeast produces acetic acid! So, it's not necessarily a contamination then.

Well... I don't think it's very common for Sacch yeast to make above threshold levels of acetic acid, but it's possible.

Could temperature fluctuations do this? Because I store it in my room with the airconditioner at 22-23C, but then I turn it off for a good portion of the day as well.

I can't think of a reason that temp fluctuations per se should cause your beer to taste sour. However, if there's contamination, the effects (i.e. acid) would be produced sooner at higher temperatures.

 

[IslandLizard]

Because I store it in my room with the airconditioner at 22-23C, but then I turn it off for a good portion of the day as well. This didn't affect my past beers but then each one reacts differently.

Even 22-23C is a bit high for yeasts such as S-04 and US-05. And it only goes up from there once the AC is turned off.

At higher ferm temps those yeasts will create more byproducts that may not taste as good.

Also, any contamination (from touching wort with hands, etc.) may take off faster than the yeast you pitched. She may need a day or 2 before she gets a good foothold and outnumbers other microorganisms.

 

[Cro Magnon]

Brew bag?
Are you referring to your mash bag? If so, squeezing that bag is fine, and since it's pre-boil, infection is not an issue at that point.

Yes sorry was referring to mash bag.....Not the infection but I thought the extraction of tannins etc from squeezing might produce these off flavours? I did notice that the times I squeezed, the wort was extremely oily to the touch (like cooking oil almost) However on the other hand...the first few beers I did this with turned out fine with no off flavours.

 

[Cro Magnon]

Even 22-23C is a bit high for yeasts such as S-04 and US-05. And it only goes up from there once the AC is turned off.

At higher ferm temps those yeasts will create more byproducts that may not taste as good.

Also, any contamination (from touching wort with hands, etc.) may take off faster than the yeast you pitched. She may need a day or 2 before she gets a good foothold and outnumbers other microorganisms.

I feared I was being a bit too lax with temp control. Although I really don't have the facilities to control temp too much. Been considering putting it in a bucket of cold water and replacing frozen PET bottles to keep it more or less on the lower side. I've been wrapping with a wet towel....but I don't know actually how many degrees in reduction this causes. Any ideas?

 

[VikeMan]

.Not the infection but I thought the extraction of tannins etc from squeezing might produce these off flavours?

Personally, I can't imagine a vinegar-like flavor caused by tannins from the grains, even if squeezing actually extracted more of them (doubtful).

 

[Cro Magnon]

I can't think of a reason that temp fluctuations per se should cause your beer to taste sour. However, if there's contamination, the effects (i.e. acid) would be produced sooner at higher temperatures.

Makes sense...if the off flavours were produced either by unhygienic yeast storage conditions or improper fermentation temps....then the higher temps during the fluctuations might have amplified these flavours. Oh well....it's looking like the sewers are going to enjoy a red ale.

 

[Cro Magnon]

Personally, I can't imagine a vinegar-like flavor caused by tannins from the grains, even if squeezing actually extracted more of them (doubtful).

Ok that's great to know....because I have such a low yield, and I make such small batches....feels awful to leave any wort in the bag.

 

[hottpeper13]

To find the cause I would first disassemble all the valving on the cold side and check for residue. The bottling wand plunger spring was the culprit for my infection.

 

[Cro Magnon]

To find the cause I would first disassemble all the valving on the cold side and check for residue. The bottling wand plunger spring was the culprit for my infection.

I WISH I had valves to dissassemble

 

[IslandLizard]

I feared I was being a bit too lax with temp control. Although I really don't have the facilities to control temp too much. Been considering putting it in a bucket of cold water and replacing frozen PET bottles to keep it more or less on the lower side. I've been wrapping with a wet towel....but I don't know actually how many degrees in reduction this causes. Any ideas?

A swamp cooler (wet towel) is better than nothing, and will drop the temps by a few degrees or prevent them from rising too high. But I think a water jacket doped with a frozen bottle (or 2) is a more active and efficient way. Insulating that whole setup from higher surrounding ambient temps (e.g., by using a thick blanket, sleeping bag), again, is beneficial.

I've used a large beverage cooler, halfway filled with cold water, in which I placed 1 or 2 6.5 gallon brew buckets. Draped with a sleeping bag, it stayed at 64-65F, using 2 frozen bottles of water a day. But that's in a coolish ~70-74F area already.

 

[Cro Magnon]

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.

Oh I missed this! Very important lesson for me here. So squeezing the strainer cloth with my hands is a no-no. Also yes, in retrospect I don't need to do such fine straining at this stage. I can leave a little bit of wort with most of the hop residue behind. And whatever comes through to the fermenter can just settle as trub.

Thanks a lot for this info! In my case the last bit of trubby wort must hardly be 200 ml so I don't know if its worth saving....

Wait....WHAT DID I JUST SAY??!

 

[Cro Magnon]

A swamp cooler (wet towel) is better than nothing, and will drop the temps by a few degrees or prevent them from rising too high. But I think a water jacket doped with a frozen bottle (or 2) is a more active and efficient way. Insulating that whole setup from higher surrounding ambient temps (e.g., by using a thick blanket, sleeping bag), again, is beneficial.

Great to know....I will give this a shot...seems very doable with minimal equipment.

I've used a large beverage cooler, halfway filled with cold water, in which I placed 1 or 2 6.5 gallon brew buckets. Draped with a sleeping bag, it stayed at 64-65F, using 2 frozen bottles of water a day. But that's in a coolish ~70-74F area already.

Never thought of a sleeping bag or a beverage cooler but what a great idea! I'll have to find a tall beverage cooler though, rather than the rectangular box kind.. Thanks for all the great info!!

 

[Dinadan]

Oh well....it's looking like the sewers are going to enjoy a red ale.

What a weekend the rats will have!

This has been an informative thread. Thank you fellows, for providing the info.

 

[IslandLizard]

Never thought of a sleeping bag or a beverage cooler but what a great idea! I'll have to find a tall beverage cooler though, rather than the rectangular box kind.. Thanks for all the great info!!

Any shape will work, as long as it fits your fermenter and the water bottles.
Mine is a rectangular one.
The water jacket only rose up about 3/4 of the beer level inside the buckets, just high enough before they started to become buoyant. The turbulence of fermentation and natural convection currents keeps the beer moving.

Other brewers have been successful by building a (2") styrofoam box in which they place their fermenter plus a few frozen water bottles.

The next step up is using a (spare) fridge or freezer and a temp controller.

 

[Cro Magnon]

Any shape will work, as long as it fits your fermenter and the water bottles.
Mine is a rectangular one.
The water jacket only rose up about 3/4 of the beer level inside the buckets, just high enough before they started to become buoyant. The turbulence of fermentation and natural convection currents keeps the beer moving.

Ah yes the ol' turbulence and convection currents! *frantically rummages through trash for 6th grade physics text books*
No No I get what you mean ...guess it shouldn't be a prob cos 8 litres of wort is pretty heavy if the the container is in is only like 4-5 inches bigger in diameter than the fermenter so I shouldn't be worried about Pennywise showing up saying "It'll float too!"

Other brewers have been successful by building a (2") styrofoam box in which they place their fermenter plus a few frozen water bottles.

This is something I can get my hands on easily. Again, never considered it!

Thanks again, Island!

 

[IslandLizard]

I never even considered saving the last bit of trubby wort....but hey..what about the fat yeast cake? Do you combine saving the last bit of wort with yeast washing? Or is it only one or the other?

Saving, straining, and re-pasteurizing the leftover trubby wort depends on if it's worth the effort. If it's 6-8 oz, maybe not. 2 quarts becomes more lucrative.

I sometimes save some of the yeast cake in a jar in the fridge. Or pitch a new batch on a part of it.

My yeast cakes are quite compacted. After transferring to a keg (3-5 gallon batches), there's no more than a pint or a quart of beer left on top of the cake. If I save it I swirl it up to homogenize it and pour into a 1/2 gallon pickle jar, or 1 or 2 smaller mason jars.

Not sure what you mean with "Do you combine..."

I rarely wash/rinse yeast. What we do is actually called yeast rinsing. Yeast "washing" is a different process that requires an acid to kill bacteria, and is typically done right before pitching into a new batch, as the acid also weakens the yeast.

 

[Cro Magnon]

Saving, straining, and re-pasteurizing the leftover trubby wort depends on if it's worth the effort. If it's 6-8 oz, maybe not. 2 quarts becomes more lucrative.

I sometimes save some of the yeast cake in a jar in the fridge. Or pitch a new batch on a part of it.

My yeast cakes are quite compacted. After transferring to a keg (3-5 gallon batches), there's no more than a pint or a quart of beer left on top of the cake. If I save it I swirl it up to homogenize it and pour into a 1/2 gallon pickle jar, or 1 or 2 smaller mason jars.

Not sure what you mean with "Do you combine..."

I rarely wash/rinse yeast. What we do is actually called yeast rinsing. Yeast "washing" is a different process that requires an acid to kill bacteria, and is typically done right before pitching into a new batch, as the acid also weakens the yeast.

I misunderstood saving trubby wort for saving the the *beer* remaining on the yeast cake after you bottle /keg....so never mind i understand what you mean....As far as washing/rinsing yeast...I've been looking through some other threads....don't want to chew your head anymore about that so thanks for all the info!

 

[IslandLizard]

I misunderstood saving trubby wort for saving the the *beer* remaining on the yeast cake after you bottle /keg....so never mind i understand what you mean....As far as washing/rinsing yeast...I've been looking through some other threads....don't want to chew your head anymore about that so thanks for all the info!

This may clarify some of the terminology used: Wort becomes beer, after pitching yeast.

Also, wort cannot be kept safely, it will spoil. To prevent that, it can be sterilized (pressure canner at 250F) or frozen.

 

[Dinadan]

I save some of the yeast cake , or trub too. I just put it in a bottle in the fridge. Maybe not the best practice, but so far it always makes beer.

 

[Cro Magnon]

I save some of the yeast cake , or trub too. I just put it in a bottle in the fridge. Maybe not the best practice, but so far it always makes beer.

Nice...I've been told to swirl up the yeast cake with the last bit of beer when saving the yeast cake. Why do we do this? Why not try to pour out as much of the remaining beer and save as much raw yeast cake as possible?

 

[Tobor_8thMan]

"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)."

I've read it's a bad idea to squeeze the malt bag as this can leach tannins that will possibly make things tart/astringent.

"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..."

Boiling hot wort pouring over ice will pickup oxygen probably at an undesirable time. Do the beers seem to go stale quickly?

"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. "

Same problem as #2 above. The wort may not be at the optimal temps for introducing oxygen. Also, instead of a muslin cloth or handkerchief use a paint strainer bag. Purchase a box of 25 (or whatever quantity). Of course, these are NEVER use for anything other than beer. Nice as they have an elastic top and easily go onto and stay onto the 5 gallon white plastic buckets many use for brewing. These will not clog. When they wear out, throw away and get a brand new one from the box.

 

[Tobor_8thMan]

I save some of the yeast cake , or trub too. I just put it in a bottle in the fridge. Maybe not the best practice, but so far it always makes beer.

Don't screw on the caps tightly or use an airlock on the bottles with the yeast.

 

[bracconiere]

.I'm now in constant fear of vinegar... Texas vinegar massacre, Vinegar the 13th, Vinegar 3: Son of Vinegar, I Vinegar on your Grave..

why i just pastuerize my fermenter....every time i do it "by the book", my beer is sour...... i just let the natural biome do it's thing.....

 

[Cro Magnon]

why i just pastuerize my fermenter....every time i do it "by the book", my beer is sour...... i just let the natural biome do it's thing.....

Not sure what you mean...you mean when you just use sanitizer your beer always ends up sour? And with regard to pastuerizing your fermenter...what is it made of? I ferment in PET so boiling it is out of the question.

 

[bracconiere]

Not sure what you mean...you mean when you just use sanitizer your beer always ends up sour? And with regard to pastuerizing your fermenter...what is it made of? I ferment in PET so boiling it is out of the question.

i use a HDPE 15 gallon one....i use it for my sparge water, so in a round about way, i've realized i'm pastuerizing it in the process.....never a sour batch....it does taste for lack of a better descriptor, "dusty"....but never sour!

 

[Cro Magnon]

I've read it's a bad idea to squeeze the malt bag as this can leach tannins that will possibly make things tart/astringent.

Yeah this bit I'm not sure about as well. I would say I've heard 50% of the time people saying don't squeeze, and the other 50 saying squeezing is fine. From trial and error, two batches came out fine, and this is the first one that's off. But I can't narrow it down specifically to the squeezing. I wonder if brulosophy has an experiment on it.

"Boiling hot wort pouring over ice will pickup oxygen probably at an undesirable time. Do the beers seem to go stale quickly?"

What do you mean 'at an undesirable time?' Well for one the ice melts pretty quick after I pour the wort over it, and it cools to just about 33C by the time I'm done. Secondly I thought at this stage since we want to oygenate the wort anyway, this is fine. Are you saying that oxygen gets trapped in some way and released at a later time?

Same problem as #2 above. The wort may not be at the optimal temps for introducing oxygen. Also, instead of a muslin cloth or handkerchief use a paint strainer bag. Purchase a box of 25 (or whatever quantity). Of course, these are NEVER use for anything other than beer. Nice as they have an elastic top and easily go onto and stay onto the 5 gallon white plastic buckets many use for brewing. These will not clog. When they wear out, throw away and get a brand new one from the box.

Thanks for the tip about paint strainer bags (I'll have to look it up, I don't know what they are). When you say wort is not at the ideal temp for introducing oxygen....what is the ideal temp?