Acid Whey Experience?

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Well-Known Member
Oct 12, 2015
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Indianapolis, Indiana, USA
I make yogurt every week and have been searching for something to do with the whey left over after straining it. Acid whey from yogurt is unlike the sweet whey from cheese in that there is very little protein or fat left - certainly not enough for ricotta or similar uses - and it has between 6% and 9% lactic acid, with 7% being average. (The remaining yogurt is much lower - 1/2 to 1 %, but the whey is higher, supposedly.)

So far I haven't found any use (except to feed some to the dog), and thought about using it in soap. I've been using prepared sodium lactate, and to be honest I have enough to last me probably the rest of the year. But since I've got this whey going to waste...

Has anybody tried substituting acid whey for the water in soap? According to the info on DeeAnna's tutorials 100g of 7% whey would be about right for 1 kg of oils, no? Would I just replace the appropriate amount of liquid with this whey before adding lye? Add about 3g more lye to account for neutralizing the lactic acid, or just forget about it and accept the slightly higher superfat?