Every year, I find onions in the harvest that are not likely to store well. These are perfect candidates for caramelized onions, a delicious, easy-to-make condiment that can be stored in the freezer.
To identify onions that won't store well, look for softness at the neck (where the stem joins the bulb). This means that rot might be extending down into the bulb. To see what that looks like, see the slideshow, below.
If you have an abundance of onions, make caramelized onions and store them in your freezer.
The first half of our summer was cooler than normal and everything in the garden grew slowly. By the end of August the onions have usually ceased active growth and the tops have fallen over. This initiates the "curing" phase when the neck of the onion constricts to seal it off from the outside world. Because the foliage on these plants showed signs of disease, and rainy September was just days away, I decided to harvest the entire crop.
I spread the onions on some scrap building paper (newspapers or even the bare floor is fine) in the barn and gave them as much room as possible. In drier parts of the country, farmers and gardeners often let their onions cure right in the row after they pull them from the ground. We get too much rain for that. I cure my onions on the floor of the barn where it's warm and dependably dry.
After a couple weeks you can start to tell which onions aren't curing properly. Instead of getting dry and crisp, the necks soften. Sometimes the top of the bulb starts to soften, too. Use them up right away and keep them from contaminating the rest of your crop. This basket contains the culls, along with a few large Spanish onions, which don't keep well anyway.
This heavy, enamel-coated cast iron pot is ideal for the job. The onions need to simmer slowly for about two hours and with a pot like this you can turn the heat down and not worry about scorching.
I have a great food processor with a slicing blade. And a mandoline, too. I always wind up using my knife instead. It may take a bit longer, but these are really nice onions and I enjoy slicing them into perfect little half moons.
Put a half cup of olive oil in the bottom of the pot and start with a medium-low flame. You don't want to fry the onions. They should not get brown and crisp. The goal is to cook them gently.
This is the neck-end of one of the onions that I culled. You can see how the stem rot has begun extending down into the bulb. Left unchecked, things will deteriorate quickly from here. Cut the bulb in half, remove the softened parts and use whatever is left.
This is a 7-quart pot, filled to the brim. The onions cook down a lot as you'll see, so don't hesitate to fill it up. Use a wooden spoon to gently mix them around, separating the rings and getting them all coated with a little olive oil.
Here I've pushed some of the onions aside to reveal the inch of onion juice-olive oil that's now accumulated in the bottom of the pan. See how white the onions are? Soft, not browned.
They're starting to cook down now and are almost completely covered in their own juices. Keep them simmering.
Once all of the onions have fully softened and some of the moisture has evaporated, add 1/2 cup of brown sugar and 1/4 cup of the best balsamic vinegar you can afford. Stir well and keep simmering.
Once everything is caramel-colored and slightly thickened, you can call this batch done. Cook much more than this phase and they start getting dried out.
I wound up with about 5 cups of caramelized onions. The first cup went on a pizza that night. The rest went into the refrigerator until morning, (when I could take a photo).
I put about a cup in each of these 1-quart bags, flatten them out and stack them in the freezer. They thaw quickly at room temperature. Last year I used them up on pizzas, tossed with pasta, and on little crackers as an appetizer. I'm sure there at least a hundred other things they'd taste good on, too.