What’s the secret to storing homegrown onions so they won’t sprout or mold? Curing. This easy process is key to making them last many months in the pantry, but it all starts with the harvest. Learn how to tell when your onion crop is ready, what to do with the flower stalks, and how to maximize their shelf life so they stay as fresh as the day you picked them.
Here we are, a whole season after the first onion seeds were sown, and those tiny black specks have slowly grown into a bed of bulging brown (or red, or white) globes pushing their way out of the soil. While onions can be harvested and eaten at any stage, the most satisfying part of growing onions (in particular, storage onions) is being able to pick a fresh onion from the pantry months after you’ve picked it from the ground. Curing makes that possible.
The key to longer storage
Curing is a month-long process of drying down your onions to prep them for storage. Once properly cured, onions store for a very long time—through the fall and winter, and sometimes even spring under the right conditions. But not all onions are created equally. As a general rule of thumb, long-day varieties store longer than short-day varieties (the “long” in long day refers to the onion needing 14 to 16 hours of sun to develop properly), and pungent onions store longer than mild onions.
Mild onions are generally large and juicy with thick rings and papery skins that peel easily. They’re sweet enough to eat raw but they really shine as onion rings and deep-fried “bloomin’ onions.” Unfortunately, most mild onions don’t last more than two to three months, even when cured and stored under optimal conditions. If your crop includes mild onions, you’ll want to eat those first. Pungent onions, on the other hand, can keep as long as six months or even up to a year. They’re usually smaller in size with thinner rings and tighter skins, and are best known for making you cry when you cut them. The sulfurous compounds that sting your eyes are the same ones that inhibit rot, so the more pungent the onion is, the longer it will store.
Onion varieties with the longest shelf life
When it comes to onions, we just have to accept that long-storing onions cannot be grown in the south. Northern climates, however, have their pick of long-day storage onions that are bred for winter storage. They include white, yellow, and red globe onions with mild to moderate pungency. Short-day and intermediate types are mostly sweet onions that store for one to three months on average. The exceptions are Red Creole, a short-day red globe that keeps exceptionally well, and Texas Legend, a short-day yellow globe that can sometimes last up to four months.