Excess (after reaction with FB is done) stays dissolved in the final product from what I see (to a point). Because the organic acids are soluble in ethyl acetate (with my cuttent materials), and also we have some water from the pull. There is published data for malic acid + ethyl acetate solubility (see attached paper),  It's about 3.7mg per gram of solvent at room temp (no water I presume), and 2.3mg/g at 10C. Fridge temp is not mentioned, I image it would be at least 1mg/g at 4C (they give parameters for theoretical calculations if anyone is interested).

Thanks for testing the citric acid monohydrate vs anhydrous at 200F. If neither is loosing weight then I don't know what I have. I thought it would dry up in the oven based on some info out there.