Effect, if any, will be very brief in soil. Use it to make bread or other cooking.

A search for "pH of whey" (without quotes) reveals that whey isn't all that acid in the first place.

You might try a different search -- "uses of whey" (again, without quotes).

Just because something is acidic doesn't mean it is a good long term way to acidify soil. Use sulfur.

I'm not sure why whey can't be composted. I would think that it is mainly water, with some protein in solution. Have you tried to compost it?

Seems to me that whey would have some good-guy bacteria and nutrients that would actually inoculate/boost your compost. I would add some browns (paper, etc) at the same time to keep things balanced. Like all things, start out slowly and analyze results.

In the cheesemaking class, they said not to put the whey on plants because it is so acidic it would sterilize the soil. So, I think putting it in compost would overly acidify the compost making it inert.

Wow,I'd like to see what the pH of that is.Sounds more acidic than battery acid.If it is,then it could probably be diluted. Brady