Are frozen onions any good? (And general advice with frozen veg)

My general rules are twofold --

• Is the item something that can be frozen whole? (yes for corn kernels, peas, lima beans, etc.)
• Is it something that I'm going to reheat, but not cook over high heat?

So, part of it's the items themselves, but the other part is how I'm preparing them ... and stir-fry just isn't something that I think lends itself to frozen vegetables in my opinion, as you want to cook them quickly, and they're not going to cook quickly from frozen. Sweating, on the other hand, you might be okay with, I've never tried using frozen onions.

I typically use frozen vegetables for things like pot pies, soups, and such, where the vegetables don't need to be at their absolute prime. Frozen peas hold up amazingly well; I'll even sprinkle them into paella or other dishes to add texture and color.

My suggestion for your onion problem would be to get larger onions. You'll spend less crying over 1-2 large onions than 7 or 8 small ones. At the very least, peel 'em all, then start cutting, so you're not exposed to the fumes slowly over a longer time.

The issue I have with frozen onions in particular (and I love other frozen vegetables) is that when you are looking to really caramelize your onions (not just cook them until they're no longer hard), you can't add liquid in the initial stages because the onions will steam rather than fry.

Water can only heat up to boiling point before it starts changing into steam. (212 F or 100 C at sea level.) Any additional heat energy is only going to make the transition from one state to the other faster -- it won't get any hotter.

Oil, on the other hand, can heat up to its smoke point -- which can be significantly higher temperatures. Thus, it can allow chemical reactions that only occur at higher temperatures. (Maillard reactions? Can someone with access to McGee confirm that for me?)

That's why boiled onions look and taste different from caramelized onions. The latter are much sweeter and have different flavors.

Frozen onions generally have enough ice inside or on them that they never truly caramelize. If you just want to get them soft enough to eat, they're fine. So it really depends on what you're doing with the onions. In fact, you might want to have some of each. If you're just using the onions in stew, for example, frozen would be fine. But if you're making a stir fry or other high heat dry dish, you'd want fresh.

I generally find that caramelized onions taste the best in all things, so what I tend to do is to suck it up and cut up 3-5 lbs of onions at once and caramelize them all down, let them cool a bit, then put them in a freezer bag and freeze THAT. Then, as I need onions, I can break off a chunk and I've got a lot of flavor really fast. I can make french onion soup in minutes, have onions to put on burgers in a flash, etc.

Most veggies will freeze fine if you know how. Mushrooms can't be frozen directly from fresh, but if you saute them up first, then they can. Carrots should be parboiled first. Same with corn and peas and the like. I also freeze things like roasted garlic, lemon zest, fresh bread crumbs, and tomato paste that I will eventually need but won't necessarily use all of at once.

I find the biggest issues with frozen vegetables from a strictly aesthetics standpoint is texture and taste. Frozen veggies almost always lose the crunch that fresh has, especially if cooked properly and not cooked to a limp,mushy mess. The firmer vegetables tend to hold up to freezing better as well.

Frozen onions are definitely limp and weaker than fresh ones, but you make a good point of time saving. I personally would take the extra time, but depending on how you are using them, like in home fries or some soups and sauces, they are a reasonable substitute

If you find you really like the fresh better, you can reduce the number of cutting/crying cycles but chopping some extra and freezing them yourself. You will get better flavor from your own recently frozen onions and have some prep done for next time you need them.

My only problem with frozen chopped onions tends to be that they're not chopped very fine. Other than that, in any cooked application, most people will not be able to tell the difference between the frozen onions and the freshly-chopped onions. Naturally, the same isn't true if you're not cooking the onions, but how many uses do you know for raw chopped onions? (Sliced, yes, but chopped?)

Personally, I'd advise against freezing onions. They last for weeks in the cold room or in the fridge, so I see no point in freezing them. Frozen peas, green beans, carrots and corn are acceptable, although never as good as fresh. The quality also depends on the freezing technique; industry uses fast-freezing techniques which lose less vitamins and texture.

It seems that freezing has to do with fiber; there is some mention of that in this Robert Lustig's talk on sugar. I highly recommend watching the whole video, but the rest of talk is not relevant to the question, so here's the link to a relevant minute or so of the talk (about 40:55 to 42:00).

i just ate some frozen onions and green pepper in tuna salad sandwiches. they were from my garden. washed chopped and frozen 8/2012 it is Now 4/2013 and they were fine. just tossed them in the tuna salad frozen and mixed up. chilled the tuna and tasted great. even crisp. and i froze them 8 months ago before winter. you'll be fine. remember you are always chancing botulism when not cooking ANY vegetable.

I usually choose chopped, frozen onions to avoid crying. But they do not have the crisp texture you want for salads, or rings for those who want rings on their burgers.

Frozen chopped onions from the supermarket are dire. They have too much ice in them and form an impenetrable mass not allowing you to see how much you are using.

I make a delicious vegetarian version of good ol NY style Matsoh Ball Soup. I have always used FRESH pearl onions. Yes it's time consuming to peel them, but the flavor they add to the broth is amazing. I just tried FROZEN pearl onions for the first time. Big difference. They had absolutely no flavor in my mouth. When they are fresh, and you get a whole one on your soup spoon, it's an immediate burst of flavor. I will never use frozen pearl onions again for this soup recipe.

Frozen onions not a problem if using in sauces or you want them broken down, the high water content in them expand and contracts the onion to affect it's structure so you need to decide what their going to be used for.