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Are there any available substitutes for greek yogurt?I don't have any in the fridge. Looking for a substitution besides regular yogurt or any yogurt based substitution. Looking to make a creamy like cold sauce for fish tacos.
Substitutions for greek yogurt?

My girlfriend and I make a large batch of yogurt every week, and have done so for more than a year now - we just eat a ton of the stuff. THis leaves a lot of leftover whey which we used to just throw out. This past week I took my first swing at making mozzarella, and noticed that the recipe suggested not throwing out the whey, but rather using it to make ricotta by boiling it. I ended up throwing out the whey from the mozzarella anyways because it was a tiny batch, and we had to make yogurt anyway.So, we made the yogurt, and my girlfriend saved they whey for me. I've been simmering it for a few minutes now, and it doesn't appear to be working. Nothing is curdling. I'm wondering if its a function of not having anything acidic in it? I tried adding a quarter teaspoon of citric acid, but still nothing is curdling. At this point I'm curious to play with it, so I may try simmering it all the way down into gjetost. So really i guess my question is, outside of being less acidic, is whey from making yogurt different from whey from cheese making?Also as a note, we use 1% milk.
Using whey from yogurt to make ricotta

I'm actually making root beer, but I've found the best way is to boil herbs and spices the same way one would make a tea, and then I add sweetener, leave it to chill, and use a carbonation device to add bubbles.So far I've been using ready made root beer ingredients that come either in extracts or in bags of herbs, like a loose leaf tea. Now I want to go the next step and make my own blend.I've got a recipe I want to try and have bought all the ingredients I need in whole form. I'm wondering if there is any advantage in grinding them up. This answer on this site leads me to believe that it's workable to leave spices whole, but I feel like that wouldn't be the case with a whole nutmeg nut. Surely the flavour would not be accessed by boiling water in such a hard and thick nut?I also learned that in the case of tea, it's actually inadvisable to boil or steep them for too long, as it releases bitter tannins. So I wonder if grinding down spices to "release" more flavour might also have adverse affects.So, bottom line, maybe you can boil spices whole, but maybe it's better to chop or grind them a little? And if so, how far should one take it?
Is there any diminishing return on grinding spices for a "tea"?