Often at the end of summer there are a lot of sweet onions that didn’t sell at market but are not storing as well as the fall storage onions. So they need to be used up. The way that I make sure they don’t just go into the compost is to caramelize them and either make onion jam or freeze the caramelized onions in a small bag for use later on.
For the record: sweet onions are not the best for caramelizing because they have more water in their cells which dilutes the acids in onions making them piquant, thus giving the impression that they are sweet. In caramelizing you have to cook all that water out before getting good color and so it takes longer and often results in a more broken down end result. But using sweet onions in a less ideal way is still better than chucking them into the compost.
Caramelized Onions for Later Use
5-10 lbs of onions
2 big pinches of salt
¼ C balsamic vinegar
- Tip and tail the onions and then slice into petals. The smaller they are cut the faster they will cook, but the more likely they are to break down. I don’t worry too much about the size and just focus on getting them cut
- In a large pan, the more surface area available to evaporate off the liquid the better, heat a good glug of neutral oil and add the onions and salt
- Cook until they are deep, deep golden brown. You don’t need to pay much attention to them while they are cooking. But don’t ever cover the pot because it will keep the water in defeating the whole purpose.
- When they start to brown a lot and get sticky on the bottom of the pan, deglaze by adding some water (or wine if you’re inclined) and scrape the brown off the bottom. It only adds color and flavor.
- And hold your nerve; cook them longer than you think.
- The absolute key to caramelized onions is the dark, rich flavor
- At the end add the vinegar and cook until the harsh vapors are cooked off (another 5-10 minutes). This gives lift to the onions without tasting vinegary.
Freezer French Onion Soup
My favorite way to use up these onions in the winter is to turn them into French Onion Soup. It is a fast dinner when there are already caramelized onions and stock in the freezer. I usually use chicken or turkey stock for this soup despite beef stock being the classic component. I find it to be too clunky and I never have beef stock in the freezer. The Better than Bullion Company makes a beef base and presumably that would work well too in place of the stock, but I haven’t tried myself.
16 oz caramelized onions
2 qts chicken stock
salt to taste
old baguette sliced into rounds and toasted
½ lb Gruyere cheese, grated
- In a medium soup pot, warm the onions and add the stock and a couple pinches of salt
- Taste and if it tastes too strongly of the onion base add a bit more water
- Warm till bubbling
- Turn on the broiler
- Ladle into an ovenproof bowl (traditional Onion Soup crocks are often available at thrift stores)
- Float the toast in the soup
- Top with the grated cheese
- Place soup bowls under the broiler and let the cheese melt and then brown
- The soup will also be bubbling and extremely hot
- Serve soon there after
If you don’t have ovenproof dishes, you can cheat by melting the cheese on the toast in the oven and then floating the whole mess on the soup. I find it to not be quite as satisfying but would be better than no cheese at all.