Malolactic Bacteria

[HickoryBrew]

So, I've been wanting to experiment with alternative ways to sour a beer. Malolactic bacteria, converts malic acid, to lactic acid. Although malic acid is not present in wort, it can be added. Diacetyl is produced, but my yeast pitched should clean that up, right? I know that adding lactic acid, often produces a "medicinal" taste. Basically I'm looking for any insight on what I may expect from such an experiment. I'm wanting to make a sour saison, by 'souring' a one or 2 gallon batch(boiling to kill the bacteria) later adding to 3 gallons of regular saison. Again, any advice would be great.

 

[BGBC]

Have you tried the 'traditional' methods of souring a beer first? Curious why you would take the roundabout method of adding malic acid, then converting to lactic acid rather than just using a lactic acid bacteria (lacto or pedio).

 

[HickoryBrew]

I have. Really just to see the changes, if any, a different bacteria might add to the final product. Who knows, might produce something great!

 

[HickoryBrew]

There just isn't that much knowledge on the Web concerning the use of it in beer. Figured this would be a good learning experiment. I don't make home brew because it's easy, I make it because I'm interested in the processes.

 

[BGBC]

I think there's not much info on it because malic acid isn't present in wort, like you said

You could try adding a natural source of malic acid (apple juice, or juice concentrate) to a beer with malolactic bacteria (maybe in addition to LAB?).

I guess I'm just wary of adding food grade acids based on the negative reviews that you describe of using food grade lactic acid to sour a beer.

 

[HickoryBrew]

Yeah. My plan was to try a natural source, as well as an additive. Some of the descriptors used to describe post FML fermentation present in wine, sounds like it could contribute pleasantly to beer. Hazelnut, dried fruit, baked bread, roasted aroma, chocolate, etc. Or, if anything, to be used in conjunction with a typical sour to add another layer of complexity.

 

[Queequeg]

If grapes contain malic acid I say try that. I recently had a barely wine fermented will grapes and it was excellent

 

[HickoryBrew]

Grapes are a great source for malic acid. Apples, pears, cherries, watermelon, are all excellent sources as well. I think maybe the hardest thing, is going to be having reproducible results due to varying amounts of malic acid. It's really the new phenols and esters I'm most excited about finding.

 

[Queequeg]

Cherries in dark sour beer are excellent as well.