Infected beers?

There are different types of infections and a beer can get infected quite a few different ways. When people say infection on here they are almost always referring to an infection of wild yeast. Wild yeast can infect beers through the air as it naturally occurs, it can be present because of beers the brewery may make with wild yeast, and it can be from a barrel previously infected just to name a few. Barrel aged beers, particularly previous use and blended barrel aged beers are more prone to infection due to the exposure of the potentially dangerous barrels, as are beers brewed at breweries that have beer with wild yeast. Generally, a beer will get a tart and/or sour taste when infected and will ferment further than intended by the brewer so can be lighter bodied than intended and overcarbonated. It can also get a funky smell and taste similar to a musty basement and a lot of other unintended flavors.

 

If your beer tastes like pure rubbing alcohol you're infected!

Cheers!

 

Or even if the beer is supposed to be bitter and roasted malts type and it turns out to be a raspberry tart fest then it is infected.

 

I've been curious about this as well. Many of Corey's descriptors pop up in positive reviews of sour beers, e.g. "funky," "musty basement," "tart," "sour." In other words, does an infected beer taste like a sour?

 

Sometimes it does. Sometimes it's even good. But keep in mind those flavors often don't mix with something like the hoppiness of an IPA and the roastiness of a stout. But, the flavors are more often bad than they are good.

 

I have heard(only speculation) that infection often is a result of bottling, that wild yeast can contract the "infection" during this process. Wonder if anyone has more info of how that occurs? It does seem that bottles from a batch will have scattered infection while the kegs seem just fine from the batch.

 

I've never had an unintentional infection that tasted good. Blech. Part of it might be expectations - if my mouth is expecting stout & it gets funk & cherry & stink-bomb, that's not a good thing in my book.

 

Infection CAN occur during bottling and not kegging - that is typically a result of poor sanitation interms of crowns, filler heads, whatever. It's not always the case.
Overall, "infection" is a very broad term and can refer to many things, caused by many things. Wild yeast is one concern, and this can happen even in breweries that do not make sours. Wild yeast is just that: wild. Brettanomyces, pediococcus, lactobacillus and acetobacter can manifest due to poor sanitation or temperature control.
Another huge issue is diacetyl, which is apparent as a buttered popcorn or butterscotch character.
Acetaldehyde is a green apple character.
Trans-2 nonenal is oxidation (wet cardboard).
Dimethyl sulfide (DMS) is cooked corn or canned asparagus.
Methyl mercaptan (skunky).
Ethyl acetate (peaches / nail polish remover).
Isoamyl acetate (bananas).
Etc etc etc.
There are many possible causes, be it teperature, rushed beer, underattenuated yeast, excess oxygen, etc. It could also be a draft line issue when referring to draft beer.
All in all, I encourage you to check out more info from White Labs, Brewers Association, or pick up Tasting Beer by Randy Mosher - a great resource for all things beer-related.

 

I hope you don't mind me ressurecting an old thread. I am still a noob to some of this, and was honestly curious. Thanks for all of the great information. Now I understand it better. I wish Central Waters did. Peruvian Morning is far too good of a BA Stout to experience this year after year.

 

The only infected beer I had was a RIS, had a slight tart Cherry hit to it. Actually wasn't all that bad. I've had skunked German beers that tasted like raw cabbage, that tasted like shit, smelled about as bad too the whole room stunk when it popped.

 

Recently had a 2012 Central Waters Peruvian Morning. When I heard it was infected back then I just shelved the beer in my garage with no intention of drinking it and didnt care how it was stored. When my buddy unearthed a case at his mom & pop i decided to give it a go. Coffee was faded, still had a bit of wood from the barrel but no booze and a little fruit like tartness. There was no excessive carbonation or rank grape juice smell when i opened it. All in all it was not bad just not what the brewer intended. Glad I started drinking fruit beers this year or I probably would have drain poured it and could see someones dismay if they were expecting a barrel aged coffee stout and tasted this instead. Might actually grab a four pack from my buddy to see if the same holds true for his PM, seeing as it was buried at the bottom of a display and has never seen the light of day.
Cheers

 

Central Waters should probably stop making Peruvian Morning. here's the beer's recent history:

2012 Release: Recalled due to infection
2013 Release: Recalled (at least in part) due to infection
2014 Release: Recalled due to infection

 

Just a few comments for clarification purposes.

The term infection is used to describe off flavors which are produced by unwanted microorganism: wild yeast, bacteria, …

Your list of wild yeast also included non-yeast microorganisms:

Wild yeast: brettanomyces

Bacteria: pediococcus, lactobacillus and acetobacter

You listed a number of other compound/off flavors which do not necessarily relate to infections.

For example, diacetyl is formed by brewers yeast during the normal fermentation process and then if the brewery provides sufficient time for the fermentation the brewers yeast will ‘process’ the excess diacetyl into other compounds. It is possible for pediococcus to create diacetyl but the majority of the time the presence of excess diacetyl in beer is an improper fermentation process.

Acetaldehyde is also a fermentation process issue.

3-methyl-2-butene-1-thiol (MBT) which is the compound that produces a skunky smell is chemical process caused by UV light interacting with hop isohumulones in the presence of riboflavin. There is no interaction with microorganism in producing MBT.

You may not have intended your list of compounds/off-flavors to be part of the infection discussion but that was not clear from your post.

Cheers!

 

I had Central Waters Peruvian morning 2014=drain pour...
I also had The abyss 2009= another drain pour.....but I will say this,after talking to Gina over at Deschutes.She took care of me above and beyond.Best customer service I've received from any brewery...they got me for life.

 

The few infected beers that I've had have each been evidenced by a gusher from the bottle and an extreme tartness on the tongue with minimal beer flavor. These seem to be the most common symptoms that I read in threads of this type, so I'm guessing that these descriptors are the most common ones that are likely to be experienced when you come upon an infected beer.

 

As was discussed by Mothergoose03, a common description for an infected beer is tart/sour/acidic. Below is an extract from the More Beer website:

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 breading 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!

Cheers!