Bryanna Clark Grogan’s Vegan Feast Kitchen/ 23rd Century Table

I know it may seem odd to start MOFO by talking about onions, but when I get hold of some interesting and useful information, I want to pass it on!  Reading books on food science can be very enlightening, even reassuring when you are proven right about some method that you have been using. Take onions, for instance. I have always used plain ol' yellow onions for cooking and saved the sweet onions for using raw. It seemed to me that the yellow onions developed that wonderful onion-y sweetness after cooking just as well as any sweet onion, and they are much cheaper. But I had no idea why.

I had ordered L.A. Times Food Editor Russ Parson's book "How to Read a French Fry" to re-read after doing my post on soaking, salting and cooking beans a couple of weeks ago. And there, in the introduction, was the explanation for the onion conundrum. It's simple, Russ explains: sweet onions taste sweeter because they contain fewer acrid sulfuric compounds and more of the enzyme which actually produces much of the onion flavor. Cooking removes much of the sulfuric acid, and, according to Russ, the humble yellow onion, when cooked, may actually taste sweeter than the sweet onion! So there was actually some method to my penny-pinching madness, even if I was unaware of it for years!

But I learned more-- the smelly, tear-inducing acids in onions are very unstable, AND they are heat-sensitive and water-soluble, which means that they vaporize when heated and can be washed away in water. Again, I have demonstrated this without knowing why it happened, pouring boiling water over sliced yellow onions, or soaking them in vinegar, to "tame" them for use in a salad. But news to me is that chilling an onion or rinsing it under cold water will prevent so many tears while chopping! Have to try that!  (Harold McGee, in his fascinating food science book "On Food and Cooking: the Science and Lore of the Kitchen", recommends pre-chilling onions for 30-60 minutes in ice water, which makes the volatile molecules in the onion less able to rise into the air and cause tearing-up, and also makes the peel come off more easily.)

Also, I learned that if you use a dull knife, it will rupture the smaller cells in the onion (called "vacuoles") which contain a variety of chemical components. These components combine and re-combine to form the sharp, smelly compounds called sulfonic acids. A sharper knife will not damage as many cells as a dull knife-- meaning fewer tears for the cook!  I knew it was time for a new chef's knife!  (Just ordered this one, which got a rave review in Cook's Illustrated magazine, despite it's low price.)

Are you bored yet? I find this fascinating, but skip to the recipe if you like! Just a wee bit more science!  The size of the cut you make in an onion makes a difference.  The smaller the chop, the faster the sulfuric acids disappear, so the onion flavor will be milder.  if you want sharp onion flavor, use a larger dice.  And how you cook it matters, too.  Cook your onion over high heat, quickly, and the onion will taste sharper and be crispier.  Cook it slowly at a low heat, and the flavor sweetens, the texture becomes melting...

                               
...which is what happens with caramelized onions and why we love them so much.  I did a post some time back about making a big batch of caramelized onions in a slow-cooker overnight (plugged in out on my deck so that the house doesn't get overwhelmed with the smell on onions!).  So, I won't repeat the instructions-- check them out here, along with my vegan onion soup recipe.  (You'll notice that I give slightly different instructions for making them with oil than for making them without oil.)  But it is certainly an easy, effortless way to make a big batch of caramelized onions, which can be refrigerated or frozen for use in many recipes.

However, if you don't have a slow-cooker or want the onions right away, try the no-fat method used in the recipe at this blog post, OR, if you don't mind using some oil, try the original version of this method  from Cook's Illustrated magazine.

Below is the recipe for the  dip. Once you have the caramelized onions ready and waiting, it's easy to make and SO much better than the usual type made with soup mix!  Chock-full of umami flavor.