When cooking are there any rules or guidelines as to when one should use a red onion versus a white one?

I don’t know about any rules, but I’ve always only used red onion for salads. I generally find my kids don’t object as much to the less visible cooked white onions in their food. Actually, I should say I use sweet yellow onions for cooking, I’ve never really used white onions for anything. I prefer scallions to onions in a lot of dishes anyway, but rarely get a chance to use them as the whole family will only eat them if I bury them in small pieces in egg or tuna salad. Heathen.

I prefer sweet onions as well. I rarely (if ever) use white onions. I only use red onions uncooked (sandwiches, salads, etc..). Stick with Walla Walla sweets (WAY better than Vidalia), you won’t be sorry!

I agree with Hossman and Supergirl: thumbs down on whites, reds are best if you want to eat them raw (although they can still be too “oniony” for many palates – in which case, go with scallions or even shallots) and yellows are good all-purpose onions. Sweet yellows are nice but for the budget-minded I think normal yellow onions are just fine for most cooked dishes.

I prefer scallions best for all dishes, but I use still red for tuna salad, and the little white ones for crock pot dishes such as stews and pot roasts. The white ones have a subtle sweet flavor but the texture is difficult to cook to perfection.

My vote is for only red raw also, but a little (and cut in very small dice or slivers) goes a long way.Now I am in paradise – gorging on fresh sliced tomatoes, just picked, w. fresh basil, fresh mozarella, and a few mini slices of red onion w. a nice vinaegrette.

Leeks and shallots are nice also, as christy “blue grosbeak” bird said.

What onion would you use for French onion soup?

Walla Walla or Vidalia for french onion soup.