Which type of onion for homemade onion rings?
You can use any onion variety you want; it depends on your tastes (and availability). White onions have a shaper, more pungent flavor, while yellow onions have a nice balance of sharp and sweet (and become sweeter the longer they're cooked). Sweet onions (Vidalia, Texas, Maui, Walla Walla) are not as astringent and have a softer and, well, sweet taste. As for reds, they're similar to yellow flavor-wise, but slightly milder.