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Feb 15, 2009 09:45 AM

Do onions get hotter with age?

My gf and I had a salad with dinner last night, but the red onion she picked up from the store was way too strong. I think the onion might have been kind of old; are older onions hotter?

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  1. I'm no onion expert, but I think it's the opposite. I think the fresher they are, the hotter they are. When I have an onion that I have let sit around the kitchen too long it doesn't seem to be as flavorful as if I used it right away.

    2 Replies
    1. re: danhole

      danhole - you're right it is the other way around.

      1. re: Linda VH

        I disagree. I think we're talking about growth age of onions, not freshness. In that case, I think, in fact I'm damn near positive, that younger onions are milder than older onions. Now maybe I'm missing a point here or there but consider this: Those little scallions/green onions/green pencil onions (whatever you want to call them) are simply regular onions that are grown and picked early. Of course they are grown for that specific purpose but if they were allowed to cotinue growing, they would turn into regular (probably white) onions. The bulb of the onion has not yet developed.

        The next step up are those salad onions that are sometimes sold in the refrigerated produce section. They are often banded together in groups of threes and sold like that. The bulb on those onions is about the size of a golf ball.

        Red onions in general are hotter than white or yellow onions. To take them down a bit you can slice them then rinse with cold water or soak for a few minutes in cold/ice water.

    2. I may be completely off the mark, but in my experience, red onions that are oblate, a little "flattened" looking, are sweeter than those that are almost "pointy" on the root end. In any case, they vary, and some are almost nasty. I don't think it has to do with age, but I hope to learn more here as well. And age can refer to time both in the ground growing, and out of the ground.

      2 Replies
      1. re: Veggo

        This thought just occurred to me - sniff the onion before you buy it. If it smells very strong, it's going to be hot. I like milder onions myself, so I avoid strong smelling ones.

        1. re: Veggo

          as a rule of thumb flatter onions are sweeter than rounder ones.

          or so ive been told

        2. Lots of factors go into the strength of an onion - the variety, when they are picked, the soil, and the water it absorbs while growing.

          White varieties are typically stronger than yellow onions which are stronger than the red. Onions picked in the fall when they are fully mature are also stronger than those harvested in the spring when onions are picked early. Onions grown in sulfur rich soil are stronger than those raised in low sulfur ground (the 'sweet' onions). Lastly (and the thing I hate most about modern agriculture of onions), are onions that are nearly flooded with water during the growing season to make them heavier (and so more profitable). The water dilutes all that wonderful oniony flavor and tends to rot more quickly.

          I'm guessing that your onion was a fall onion, gown in a high sulfur soil, and either raised as an onion should or had moisture loss during storage. All onions should be tasted before using and tempered for the application. For a salad, rinsing the chop and then immediately using will reduce the strong flavor - onions become stronger the longer they sit after cooking.

          Hope this lecture helps - there will be a test on Friday.

          4 Replies
          1. re: alwayscooking

            You think, or know for a fact, that red onions are stronger than yellow? I always thought red ones were stronger, just because they give me indigestion, as do white ones, but yellow not nearly as much. Of course I am speaking about eating them raw. Cooked white or yellow are fine. Now someone once told me that if you mince white onions finely and then rinse them they are more mellow. What do you think about that?

            1. re: danhole

              Just speaking overall, IMO red onions are milder than red hence their general use in raw salads. But his varies dramatically from onion to onion so I always taste and adjust.

              Since the sulfurs from onions are crushed and released during cutting, rising would definitely reduce the harshness from any raw onion. Don't know why only the red ones would impact you - maybe it's the pigment in skin (?) or the red onions you're using are just stronger than the whites you tend to use.

              1. re: alwayscooking

                As a rule I don't buy red onions unless my oldest daughter comes over. But whenever I eat them raw they really bother me, but so do the white ones. My favorite place for chicken salad changed the recipe and added red onion to it and now it is ruined for me. Waa! It does seem like if they are finely diced versus large dices, then I have less trouble. Sad part is that I like the flavor, it just doesn't like me!

            2. re: alwayscooking

              I think you're right! Want a polished apple?

            3. Soak red onions in cold water for 10 minutes or so before using them in a salad. They will be more mellow.