Adjusting for canned products
I live in So Cal and will be going to visit family in Buffalo next week. I am always asked (and love it!) to make mexican food while i am there. Getting tomatillos fresh is a huge problem so i need to substitute canned. My problem is that i have no idea what would equal adding x amount of canned product to a recipe that calls for x amount fresh. Eyeballing it is certainly an option but then simmering time etc always lead me to having to adjust things a lot. If i were to usually use a pound of fresh tomatillos for a sauce what would you think that would be in canned tomatillo?
I am East of Buffalo... almost at the ocean and tomatillos are in every farmer's market right now. You might want to confirm with your family that Whole Foods or local markets really don't have fresh tomatillos.
I have never had to buy canned, we get imported during the winter, so can't help you with the conversion.
I don't know the answer to your question, it might be easiest to buy extra, and go by the thickness of the sauce or soup (I'm picturing enchilada sauce, salsa verde, or tomatillo based soup) based on your previous experience. I would also make sure to adjust the salt level down a lot, that canned stuff can have MASSIVE amounts of salt in it...
Honestly? I'd pick a dish that I knew had ingredients I could get wherever I was at. There are plenty of great mexican dishes without tomatillos :)
A 28oz can of tomatillos should be sufficient. I don't think I've seen smaller (e.g. 15oz).
Sometimes I use a green salsa that lists tomatillos first. For example Trader Joes.