Lactic acid addition during boil?

[BeerBoy]

A minor storm has been created around the process of a brewer who "adjusts" their wort pH by adding lactic acid during the boil (and not for/during mash. pH was not checked until all the wort was collected and near boil). I did some searching and could not find any reference to this practice.
I am wondering: do any brewers out there add lactic during your boil (for whatever reason)? Would the lactic acid "survive" the boil and carry-over to the finished beer? Or convert to some other acid, say acetic (I know, I know - study your chemistry...) because I perceived acetic in the beers vs. a lactic off-flavor (there are a number of other questionable practices as well).

[Dave Suds]

It has been shown that the pH value of the mash is an essential parameter for the enzymic reactions. Thus lowering of the pH to 5.6 to 5.5 results in
• A higher attenuation limit
• More extensive protein breakdown resulting in the production of more high and low molecular weight protein degradation products
• Reduction of the viscosity
• More rapid lautering
• Restiction on the increase in color on wort boiling

As a result of the lowering pH of the mash, however the activity of the phosphatsases is enhanced and they increase the buffering capacity by releasing phosphate ions. Consequently the decrease in pH during fermentation is less and the effect of the acidification is as good as eliminated.
For these reasons an additional wort acidification plays at least as big a role as the pH correction of the mash. These values can be corrected with lactic acid.

Brewers want to therefore control the pH so that:

The mash has a pH of 5.4 to 5.6, and
The total wort has a pH of 5.1 to 5.2

By monitoring these values in both the mash and boil the advantages are very great.
• Shortens total mash time
• More rapid lautering
• Less increase in color in the total production stage
• Better brewhouse yield
• Slightly better stabilisation of the zinc content
• More rapid fermentation and maturation/conditioning
• Better foam and foam stability
• Softer beer taste

Cheers,
David Meadows
Sigtuna Brewhouse, Sweden

[crassbrauer]

Adding lactic acid during the boil in addition to adding it to the mash is common in Germany. It's generally added near the end of the boil, because isomerization and other important processes occur better at a higher wort pH. Yes, it survives. No, there's no "lactic" off-flavor.

[gitchegumee]

Crassbrauer, addition of chemical acids to beer worts in Germany? I was under the impression that only sauermalz could be used due to Reinheitsgebot restrictions. Am I wrong?

[crassbrauer]

No it's all Reinheitsgebot. The lactic acid is produced using the bacteria on the malt.

See the thread from October called lactic acid under quality control .

There's a reply in that thread about how it's produced.

Cheers :)