Taming red onions

[bobmac]

Frequently in restaurants I encounter red onions that are sweet and have no harsh bite. Frequently at home I slice a red onion and it has a harsh bite. Are the restaurants getting sweeter onions to begin with or are they processing them somehow? I once read a newspaper food section story in which a woman in a Middle Eastern restaurant was salting onions to tame them, but unfortunately the writer did not elaborate. I suppose salt would draw out the juices, but then what?

[Gifted Gourmet]

The red onions I buy for use at home are generally sweeter than the other varieties of onions ... of course, I live not far from Vidalia, Georgia, and we have the sweetest of onions all summer ... just found a cool recipe for red onion marmalade .. love red onions and never salt them ...

[RSincere]

Sara Moulton soaked them in cold water in one of her shows, because she was going to use them raw in a salad, and she said that removed the bite.

[Behemoth]

Lebanese people soak 'em in cold water for about 30 minutes. The water may have salt in it, though we never used any. After soaking, rinse them in fresh cold water to get rid of the milky stuff.

[Jinmyo]

If they're the main component in a salad, I'll blanch in boiling salted water and then shock in ice water.

[andiesenji]

I learned this many years ago, it was also in a magazine interview with James Beard.

If you have a very strong or pungent onion, slice it, spread the slices on a towel (paper towels works for me) sprinkle lightly with salt (I use kosher) let set for 15 minutes then place in a shallow pan, cover with milk and soak for another 15 minutes or so, remove a slice, rinse and see if it is now sweet, if not, leave it a bit longer, 20 minutes at most. Then transfer to a colander and rinse. This also works with really strong garlic.

Edited July 4, 2004 by andiesenji (log)

[chezcherie]

also, the older the onion, the more bite it will have. if it's sprouting, stand by for tears!

[elion_84]

I've often seen sweet red onions at our local farmer's market. They are similar to Vidalia or 1015 sweet onions, just red in color. I bought a small basket that had white, yellow, and red sweet onion a couple of weeks back. I haven't compared them side by side, but all seem to have very mild, sweet flavor.

[NulloModo]

also, the older the onion, the more bite it will have. if it's sprouting, stand by for tears!

I thought sprouts meant it had gone bad. All of my onions which are sprouting tend to be soft on the inside, so I figured they were rotten and tossed them... If I'd known they had just gotten stronger I would have used them, I like an onion with a nice hearty bite...

[chefdg]

Sara Moulton soaked them in cold water in one of her shows, because she was going to use them raw in a salad, and she said that removed the bite.

I second this technique, only I use ice water. They come out nice and crunchy and "deflamed".

[russ parsons]

and if you look closely, you'll see a trace of a milky liquid in the water ... that's the chemicals that lead to the tearing reaction (fun fact: they're called "lachrymator factors").

blanching would be most effective, but it would soften the texture of hte onion. the cell walls are extremely fragile. even hot water will soften them.

something else htat works is soaking the onion in vinegar (like mexican onion pickles). the acetic acid overshadows the sulfuric acid.

Edited July 6, 2004 by russ parsons (log)

[col klink]

When I soak my onions in water, I usually add some vinegar too.

[bilrus]

Everybody's favortie Rick Bayless seems to recommend rinsing chopped onions to remove the 'strong' taste in nearly every recipe I have tried from his cookbooks.

Doesn't the technique of salting the onions make the onions a little mushy?

[fifi]

russ can probably tell us what the compounds are in onions that cause the "bite" and tearing. (I could look it up but I am too lazy. ) Anyway, when you cut the onion, the compounds are released from the broken cells, combine, and presto-chango, LACHRYMATORS!

In Mexican cuisine, chopped raw onion is a common condiment served with any number of things. It is almost always white onion. The almost universal practice is to rinse the chopped onion under cold running water. This rinses off the offending lachrymators. (I love typing that word.) I can't imagine longer soaking in whatever would make a huge difference.

[Carolyn Tillie]

When I soak my onions in water, I usually add some vinegar too.

I add lemon juice... I learned it from a 90+year-old Japanese man...

I always have sweet onions!

[russ parsons]

onions are one of my favorite things in food science. they are such a basic ingredient, but it is only within the last 20 years or so that science has progressed far enough to begin to understand what is going on with them. much is still unknown.

essentially, and (i hope) briefly: onion cells contain a mix of chemicals. when you cut an onion or otherwise disrupt the cell wall, those chemicals combine which sets of a long chain or reactions that end up in the lachrymator factors which, when mixed with the mucous in the eye, turn to a type of sulfuric acid. one of the scientists i talked to once described it as a "cascade of chain reactions that happen in the blink of an eye." a really arresting metaphor from a geek, no?

another interesting fact about onion chemistry (see, now you've got me going), is that the so-called "sweet" onions (vidalia, walla walla, texas 10 150 maui, et al), aren't actually any sweeter than regular brown storage onions. in fact, they frequently contain less sugar. what makes them taste different is that they are markedly lower in LFs than other onions. BUT ... and it goes on ... it's important to remember that LFs are volatile at very low temperatures (which is why they turn to gas on the cutting board and go up into your eye). cook them and the LFs go away almost completely ... SO ... cooking a sweet onion is a waste of a premium ingredient.

[John Braise]

another interesting fact about onion chemistry (see, now you've got me going), is that the so-called "sweet" onions (vidalia, walla walla, texas 10 150 maui, et al), aren't actually any sweeter than regular brown storage onions. in fact, they frequently contain less sugar. what makes them taste different is that they are markedly lower in LFs than other onions. BUT ... and it goes on ... it's important to remember that LFs are volatile at very low temperatures (which is why they turn to gas on the cutting board and go up into your eye). cook them and the LFs go away almost completely ... SO ... cooking a sweet onion is a waste of a premium ingredient.

That's one of my favorite bits of food trivia. I think I learned it from "How to Read a French Fry"...

oh wait...

Another one (which I haven't verified) was from Lynne Rossetto Kasper. Supposedly, onions cut longitudinally (root to tip) stay more crisp than when cut the other way (into rings or half-rings or whatever). I'm guessing that it preserves more of the onions internal structure, similar to slicing a flank steak across the grain vs. with it.

[Kevin72]

Just in the past week I've taken to sprinkling the raw onions for a salad with vinegar and letting them stand for 20 minutes, then a rinse. It doesn't make them "sweeter" to my taste but does remove their harshness. It even worked on scallion whites!

[Bicycle Lee]

you could do it a la Charlie Trotter and put the slices in a dehydrator at a very low temp for about an hour...this makes them sweeter and more mild.