Acid Washing: No problems using Citric Acid, right?

[biertourist]

I've got a brewing buddy who has managed to grow up the Scheniderweiss strain from a few bottles and it still produces good tasting wort, BUT it has a slight vinegary smell so I fear acetobater has setup shop.

I know that the commercial breweries us a combination of nitric and phosphoric down to a ph of 2.2 for Acid washing but at the moment I only have access to lactic and citric acid.

Does anyone think that a solution of citric acid and pre-boiled water that yields a PH of 2.2 would be a problem? Is there some specific reason that Nitric+ Phosphoric is used in yeast washing?


Adam

[ajdelange]

The only potential problem I see with citric is that it isn't particularly strong (first pK = 3.14) so that a lot would be needed (about 6.5 g/L) to attain pH 2.2. Compare with phosphoric with first pK = 2.12. You'd only need about 1.3 g/L for pH 2.2 with phosphoric.

[njbabs]

ajdelange is dead on.

In a pinch I used citric acid (actually an acid blend, but it was mainly citric). Had to use WAY too much and it began effecting flavor (of the yeast slurry at least).

[njbabs]

Additionally, acid washing is really preventative. If there is an infection, you'll have trouble to eliminate it (certainly completely) with acid washing.

The important elephant in the room is if it is acetobacter you will struggle to treat it with acid, as they produce this and thrive in acetic environments.

Maybe some Chlorine Dioxide tabs would be a better option?