Lactic Acid replacing Citric?

Is there a rule of thumb for subbing 88% Lactic (like the kind sold by Carlson) for Citric Acid crystals (also sold by Carlson)?

Technically, I'm asking regarding cheesemaking, but I thought the scientists here would have the answer -- apologies if I should move the question to the other forum -- and I thought the answer might be of interest to people who want to change their mash PH or add sourness to their beer without a sour mash.

The situation is that many Mozzarella recipes start by telling you to add citric acid to warm milk. I have lactic on hand and would like to use it instead. The acid is the thing of value -- the flavor is supposed to be largely interchangable at the amounts in question -- generally 1.5 teaspoons of citric acid per gallon of milk.

If anyone can provide a rough estimate (or even precise amount) of how many grams of lactic would equal 5ml of citric, I would appreciate it.

You can use the acidification calculator in Bru'n Water for that evaluation.

The equivalence depends on the target pH as both are weak acids. The graph below shows the equivalence as a function of that pH. If you want to know why we can get into that.

Looking at things by the light of day it seems that 1 mL lactic acid for 1 gram of citric is a rough approximation at any pH likely to be of interest.

ajdelange said:

The equivalence depends on the target pH as both are weak acids. The graph below shows the equivalence as a function of that pH. If you want to know why we can get into that.

Looking at things by the light of day it seems that 1 mL lactic acid for 1 gram of citric is a rough approximation at any pH likely to be of interest.

Click to expand...

Thanks for the reply, that's helpful. I'll go with 1 ml to 1 g.

The recipes for Mozzarella I've seen are a lot less precise than the calculations for changing mash pH -- you'll see some say 1.5 tsp citric per gallon of milk, but others vary by 25% or more. I'm guessing yeast is a lot more fussy than rennet, or maybe the large amount of calcium in milk has something to do with it, or both.

As AJ mentioned, the equivalence varies with pH. Bru'n Water does that calculation.

Try 0.18% by weight of the milk, so for one gallon use 0.25 oz.. From my experience, that's 1 1/2 tsp., which is bout the same as a lot of recipes call for with citric acid (1 1/2tsp). I know this thread is old but I wanted to put this information out there in case anyone is searching for the answer, it is a good question after all, what better acid to use in cheese making than lactic acid as it's working in a lactose environment.

I've just learned that sodium citrate is used with cheese as an emulsifier so there may be more to the story than just the acid base properties.