I have about 16 oz of extremely old yogurt. What would be the best use of this? Should I feed it to my worms? To my black soldier fly larvae? To the chickens? Should I mix it with water and put it directly into the garden?
In my experience, unless yogurt is fuzzy, or has taken on an unnatural tint, it should be fit for human consumption still. If it's past the point where that is an option for you, I'm sorry, I don't know which of your alternatives is the best use.
Just a thought: isn't putting dairy into compost usually not recommended because of how it attracts animals? I think watery yogurt in the garden might do the same thing.
Sorry if that's not very direct advice, just my two cents!
If it has any darkish green or turquoise mold on it anywhere, then don't eat it. If it's effervescent against your tongue, depending on your constitution, it might send you down the hall at a fast pace in a couple of hours.
It is good for tomatoes, as a source of calcium against blossom end rot in some tomatoes, when mixed with water and poured in one place at the roots. When powdered milk used to be cheap we used to add that to the soil we planted tomatoes in for the calcium, but it's quite expensive now.