Infection/Quality Problems: what we should know

This may be a dumb question, but are certain beer styles (or certain adjuncts) more prone to infection than others?

 

Tom, it sounds like Bruery is taking proper QA/QC steps in this regard:

“First, we are testing the microbiological stability of every single clean barrel before the beer is blended together in the brite beer tank. With over 3000 barrels, this is a huge undertaking for our Quality Control department, so now we have two full time employees in this department. We are proud to have a world-class lab onsite at our small craft brewery, and thanks to our lab, we are able to track the health of our living beer at all stages of its life. Not only do we re-test beers weeks and months after their release, we keep archives stored just for lab tests further off in the future as needed. You can read more about our quality assurance practices on this blog post, where more details are explained.”

Above courtesy of @Jacobob10

Cheers!

 

This is a great question. Anything that isn't or can't be pasteurized would be likely candidates.

 

It's worth mentioning that we pasteurize the beer before it's bottled. Our 750 mL bottles are bottle conditioned/carbonated.

 

Yeah, thanks. I saw that when he posted some of it above. Its looking more and more like that level of care is going to have to become the norm for barrel aging programs.

 

Yes. Generally speaking, low ABV, low BU beers are more prone to microbiological spoilage since alcohol and iso-alpha acid are inhibitory to some bacteria. Also, beers that aren't completely end fermented (i.e. contain fermentable sugar) are also more prone since they have the ability to support growth of just about anything (bacteria and wild yeasts). Also, beers with very low package oxygen levels can support some pretty nasty bugs that small brewers used to not worry about, like pectinatus.

 

Hopefully that is indeed the case. This type of effort comes at a cost (large cost?):

• Hiring technical staff to monitor the beer in the barrels
• Drain pouring that barrels which do not meet spec

Cheers!

 

What types of yeast do you add for the bottle conditioning phase?

Do you ever bottle conditions with wild yeast (e.g., Brett)? If so, how long do you recommend aging those beers in order for the wild yeast flavors to develop?

Cheers!

 

The one infected beer I had was from a case I purchased locally. The source of the infection had been found about the time I had drunk the first beers from the case. I returned my case to the retailer and the brewery replaced it with a case of uninfected beer. No problem, no hassle.

 

The Smokestack Series 750s are bottle conditioned with DV10, a champagne yeast.

Yes. Saison-Brett is inoculated at packaging and is bottle/keg conditioned. We store the bottles/kegs in the bottle conditioning area of warehouse for around 3 months to be certain that the beer has noticeable brett character at the time of release.

 

maybe a stupid question: but does pasteurization stop the beer from being able to age further? is it just the yeast being killed off by the pasteurization?

 

It depends on whether you would like for your beer to 'evolve' with time in the presence of yeast. Sometimes people purchase some styles of beer with the intention to cellar the beer and the presence of yeast in the bottle may enhance the bottle conditioning/aging aspect of the beer; desirable flavor development.

The benefit of pasteurization is that it kills all microorganisms in the beer: unwanted microorganisms like bacteria but also any brewer's yeast that may be present as well. IMO this is beneficial for a beer like Budweiser since this sort of beer is not intended to be cellarable.

Even with pasteurization the beer will 'change' with age but those changes will not typically be for the better: oxidation processes will occur which will result in stale flavors being developed.

Cheers!

 

dont most bigger breweries pastuerize for the sake of uniformity? for example; would SN bigfoot age much differently if it was bottle conditioned, or would the development be similar to how it is now?

As a novice hombrewer I'm just starting to understand the science of yeast and yeast infections. (pun intended)

 

I actually was wondering about this, because I didn't think pasteurization kill everything - it just knocks down most of the microorganisms, so it would improve shelf life and stability, but doesn't eliminate the possibility of bugs coming back over extended periods of aging. It would absolutely have a big impact though and it would make a lot of difference to how long before you even noticed something developing - especially if you kept the beer cold.

If you wanted to kill all of the bugs you would have to use UHT (Ultra High Temp) pasteurization which is what they do for the shelf stable milk that lasts for 6 months or a year - it is basically sterilizing the liquid. It is a pretty savage process (the liquid is heated to over 280 degrees for a few seconds) and they have to do it with very specialized equipment. Pretty sure you wouldn't want to do that to a beer...

 

I am aware that mega-breweries like AB and MillerCoors generally pasteurize their packaged beers (bottles, cans) for beer stability reasons.

The majority of craft breweries do not pasteurize their beers.

I prefer to drink non-pasteurized beer since I have an opinion that pasteurization can have a negative impact on the resulting beers flavor. Some authors use the term of "cooked flavor impact" to describe this.

Cheers!

 

Pasteurization takes care of beer spoiling organisms. It's not possible for anything to "come back."

 

I would think that milk stouts have to be a problem, just because lactobacillus obviously loves lactose. Where there is food, there are bound to be problems.

 

Interesting thanks! That is different than most other food products, but I guess the beer already has other preserving agents (like alcohol for a start!) So that if the microbe load is low enough it is effectively the same as sterilizing.

Thanks for the info!

 

But hopefully the brewery is practicing proper sanitation so there is effectively no lactobacillus present in the beer.

I have had a number of commercially brewed Milk Stouts from brewpubs to packaged beers (e.g., Left Hand Milk Stout) and so far I have never noticed any infection related off flavors in any of those beers.

Cheers!