sourdough interferring with beer?

[Diana]

I have been reading on a beer brewers forum where I read pieces of guys forbidding their wives to make sourdough bread, coz it ruined their beer.
I have done both in the same kitchen, beer became beer, bread became bread, what is the deal there?

[svakanda]

beer snobs....:P

just kidding, sorta...my father is a brewer by trade. he is a little wary of non-controlled/lightly-controlled fermentation. partly I think because when you are making beer to sell, you want it always to be VERY close to the same as it was or you deter people....so they are much more PRECISE about their fermentation projects. I call him a beer geek. =)

[Tim Hall]

According to many beer brewers LAB infections (they refer to them as infections) are difficult to eliminate from equipment and utensils. LAB grows pretty quickly (as does just about everything) in malt medium, and unless you're aiming for something like Berliner Weiss or Lambic, it's generally considered a serious fault.

[Diana]

Thanks for the replies. I can see the point a bit yeah.
Good thing is that we love the slightly sour weissbier here very much.
Other than that I can always do the beer (non sour) in the basement and the bread in the kitchen.

What other stuff can interfere with each other?

[Tim Hall]

Diana, as long as you keep things clean and sanitized you shouldn't have to worry too much about cross contamination with most things. Wines generally have an acidity to help thwart infections and most lacto-fermented products already contain a motley bunch of bugs or are too saline/acidic to allow infection.

Beer is the exception to this (unless you're not afraid to truly let things go wild.) Malt is THE ideal growth medium for just about everything you can imagine because it has low acidity and a high nutrient profile. Just about everything floating around in the air wants to gobble it up. That's why it is commonly used as a laboratory medium for growing cultures.

[Pillar]

I could see how sourdough would "contaminate" beer, but only if the beer was being wild-fermented. I wonder if this is one of those older, traditional wisdoms that don't apply to today's situation of beer brewing with airlocks?

If your beer is closed off with an airlock or balloon, I don't see a problem arising. Its my understanding that this is what the airlock is for.

Does anyone have any experience with beer getting contaminated thru an airlock by nearby yeasts?

[Tim Hall]

With regard to LAB infected beer, the airlock isn't the issue. The issue is making sourdough and other lacto-fermented goodies tends to put a lot of LAB in your working environment. LAB is fairly tenacious when it comes to cleaning and sanitizing. So the issue is contact with contaminated surfaces. An airlock should keep everything out unless you let run dry or fill it with something that promotes microbial growth.