Where most savory recipes begin. Onions are storage organs full of sugars, which is why patient heat turns them from sharp to deeply sweet — caramelization is just those sugars being coaxed out.
On the palate
Flavor
Raw: sharp and sulfurous. Sweated: mellow. Caramelized: sweet as jam. Yellow is the all-rounder; red for raw; sweet varieties for frying.
Handle with care
Prep & knife work
·
Sharp knife = fewer tears; a dull blade crushes cells and releases more irritant.
·
Root end holds the layers — keep it on while dicing.
·
Soak raw slices in cold water 10 minutes to tame the bite.
At the stove
Cooking methods
Sweating (low, translucent, no color)
Caramelizing (40+ honest minutes)
Pickling
Roasting in wedges
Flavor friends
Pairs well with
Beef
Thyme
Gruyère
Vinegar
Nearly everything
Out of it?
Substitutions
Shallots (finer, sweeter)
Leeks (milder)
Fennel (anise note, similar texture)
Keep it fresh
Storage & shopping
Storage
Cool, dark, dry, ventilated — and away from potatoes, which release moisture and gas that spoil both.
Shelf life
Whole: 4–6 weeks. Cut: 7–10 days refrigerated, wrapped.
Seasonality
Storage onions year-round; sweet spring onions in late spring.
Shopping tips
Heavy, firm, papery skins. Avoid green sprouts and soft necks.
Nutrition
Quercetin, vitamin C, prebiotic fiber.
A longer story
History
One of humanity's oldest cultivated plants; Egyptians took oaths on them, and every cuisine builds on some version of onions-in-fat.