Various onion colors and cooking- what's the difference?

I, like all people with taste :wink: , love onions. I eat onions in absolutely everything- with my eggs, on sandwiches, burritos, on and on. One thing I have always wondered: what is the difference between a red onion, white onion, and yellow onion (aside from the color, obviously)?

Now, I know Maui onions (what I would consider a specialty onion) are sweet-- and lovely*. But let’s stick to ordinary, grocery store varieties: red, white, yellow.

Do certain foods lend themselves to certain varieties of onion? Is there no significant difference? Am I missing a whole world of oniony-goodness?

*Note to self: Go to Maui for onions.

Red onions are generally the strongest flavored onions. Whites are slightly milder than yellows, though some yellows (like the Vidalia) are very mild.

I love Vidalia onions. Use 'em in all my recipes that call for onions. You can chop Vidalias and they don’t make your eyes water. I like that, in addition to the delicious flavor.

The rule of thumb is white, yellow red for increasing levels of hotness. HOWEVER, since the milder onions[Vidalia, Maui,Mayan, etc.] have captured a large segment of overall onion sales, I suspect growers have begun to farm varieties that are not quite so hot. Back in the day, onions really used to start the tears flowing on the first slice. Today, not quite as much. Scallions are so mild now as to taste somewhat soapy. Red are good raw, they really spice up a salad or a burger. Mexican foods seem to call for the milder white onions. Good ol’ yellow onions[I like these best, nice and pungent] are fine for GP cooking, either a quick saute or slower, moister cooking, as in stews and soups. Any onion becomes milder after you cook it. The word caramelization is quite overused in cooking today, but it certainly applies to onions. Long cooking, over a low flame[so as not to burn them] will cause the natural sugars to brown and change the rawness some people object to, to a much sweeter, less harsh and more acceptable well-rounded flavor. Garlic has it’s own properties, NEVER BROWN GARLIC. Once the bitterness is extracted by too much heat, you may as well throw it out. Shallots should always be cooked, IMHO. A gentle cooking in a bit of butter or oil releases their unmistakable perfume and delicate taste. As you note, onions are quite popular, and many dishes would be bland without them. You can certainly mix onion colors in the same dish, I make great smothered onions using all three colors, but also sometimes, just yellow. Vive l’oignon

Living in GA, I may literally have vidalia’s growing out my ass. As a sweet onion they are OK but certainly not all that. I haven’t had the chance to sample Maui’s or Mayan’s, but when I lived up north I used to be able to get Walla Walla’s. Now that was an onion. Perfect for a sandwich. Course, no one down here has even heard of them. Sigh.

Just to put in my 2 cents worth, if you are going to cook the onions, don’t bother with buying the more expensive onions like Vidalia or Walla Walla. Those onions have less sugar than you regular grocery store onion. the reason they taste sweeter raw is because those varieties have less of the stuff that makes your eyes water and also gives raw onions the “bite”. So if you want a milder taste while raw go for the Vidalia etc and if you want the sweetness when cooked use regular yellow onions.

I’ve found that the red onions are less mushy after you cook them. I use them if I want a crunchier texture.

Vidalias are perfect for grilling. Mmm Mmm.

And did you know that you can pre-chop onions and freeze them? I usually have a zip-lock of pre-chopped onions for tuna salad, etc. By the time you mix all the ingredients they have thawed out.

A properly sauteed Vidalia onion is an orgasm on a plate.

Properly Sauteed Vidalia:

Slice one (or more) Vidalia onions. Put a half a stick of butter in a skillet and melt. When the butter is liquid and sizzling, separate the onion rings and throw in the skillet. Reduce heat to about medium. Cover the skillet until the onions are soft, stir every few minutes to keep onions from burning. When the onions are soft, remove the cover and let the onions brown as desired. Drain the excess grease if you want, but I don’t; I just use a slotted spoon to get rid of some of the excess.

Use as you would any other cooked onion. Gustatory and olfactory ecstasy await!

Robin

Do either of you have a cite? I always thought it was (ignoring the supersweet Vidalia, Walla Walla, Texas 1015, etc.) red, yellow and white in order of increasing heat.

I just checked a few cookbooks and couldn’t find much. The Food network has this to say:

The National Onion Association has this to say:

Alton Brown contributes this, which seems to agree with my experience:

Anybody got the Straight Dope on onions?

(And how to code the trademark symbol?)

One thing to remember is that raw onions have a stronger flavor than cooked onions. Here in NY there are onion breeders who are marketing their onions as cooking onions by saying that milder onions like vidalias are best for eating raw but have too little flavor after cooking. Obviously this is a marketing ploy, but it is important to pick onions based on whether or not you plan to cook them.

Yeah, I found that weird as well. I generally treat red onions as “salad onions,” or onions to be used raw, or possibly quatered and skewered in cooking. The varieties I get around here, at least, are certainly less pungent than yellow onions. I’ve always known red onions to be classified as very sweet and suitable for raw ingestion. I do not like red onions for most frying applications, as they tend to stay firm. I also do not like Vidalias for most purposes, as they don’t taste like onions. I’d rather eat a red onion if I want something sweeter.

In order of sweetness to pungency, I would rank the onions as follows: red, white, yellow. White onions are more juicy and watery than yellow, thus tend to be a little bit on the sweet side. White onions are also good raw, but work equally well in sautees.

Ah ha. Just to show that I’m not going nuts in my assessment:

From here.

Here.

And here.