How to Make Vegetable Stock From Kitchen Scraps
Thrifty, easy, and flavorful: Making your own vegetable stock from scraps wins the Triple Crown of home cooking. The basic method and idea couldn't be simpler — it really is just veggie trimmings and water — but consistently good, balanced flavor begins with knowing your scraps well and prepping them for the pot.
Saving Vegetable Scraps for Stock
I save prepped scraps in two separate, clearly labeled, freezer bags, divided by the primary flavor profile they contribute. Vegetable peels don't need prepping before they're frozen, but larger scraps should be chopped into small pieces, roughly 1" in size. When I'm ready to make a batch of stock, I grab equal portions from each bag.
- Vegetables that add sweetness include carrots, parsnips, golden beets, fennel, corn cobs, pea pods, and leftovers of previously roasted vegetables.
- Vegetables that contribute savory bass notes include onions, leek tops, mushroom stems, spinach, chard, squash peels.
Avoid These Vegetable Stock Mistakes
Not all vegetable scraps should meet their fate in the stock pot. A couple — red onion skins, red chard stems and red beets — will tint the stock purple. If you're planning to make borscht or other richly colored dishes, it won't matter, but a violet-tinted mushroom risotto isn't very appetizing.
The starch in potato skins can turn stock gummy, while all members of the cabbage family (this includes cauliflower, collards, broccoli, Brussels sprouts and all varieties of cabbage and kale) add unpleasant bitterness.
A few are a little more subjective. I avoid all types of peppers as well as zucchini; although I love their flavor in soup, I find that they make stock bitter. I also avoid carrot tops, which I find both bitter and soapy tasting whether they're raw or cooked. Plenty of cooks like them (pesto is their most common use), but there is a sizeable anti-carrot-top club, so taste and decide for yourself. If you like them, add them to your savory vegetable scrap bag (see above.)
Related: How to Eat Every Part of the Plant
Tips for Making Vegetable Stock
Try my recipe for Vegetable Scrap Stock.
This recipe can easily be doubled or even quadrupled, just keep the scrap mixture evenly divided between the 2 groups. While the Parmesan rind is purely optional, it adds wonderful, cheesy depth to the flavor.
With a basic formula of 2 cups chopped vegetable scraps to make 1 quart of stock, it's easy to scale depending on how much you want to make. Other than water and your frozen scraps, you need very little to complete cooking except for a quick sauté. You can do this in the same pot you'll simmer the stock in.
Sauté to Deepen Flavor
A small amount of fat — olive oil, in this case — goes a long way to enrich a stock's flavor. Sautéing the scraps together for a few minutes before adding the water gives depth to the final stock that will be noticeably lacking if you ignore that step. Think of it like browning meat at the beginning of a beef stew recipe: Sure, it's possible to skip it, but developing the meat's color early makes all the difference in the final flavor. In the case of vegetables, it jump-starts the process of melding their flavors so the simmer is more about concentrating their essences rather than extracting them in the first place, while the richness from the olive oil helps those flavors melt in your mouth rather than wash away in the water.
The most flexible optional ingredients include garlic, fresh or dried thyme, bay leaves, and peppercorns. I frequently add a splash of white wine, or an even smaller splash of cider vinegar, for a touch of acidity that will make the other flavors pop. For richness, and if I don't aim to be vegan with my stock, I'll add a small chunk of a non-waxy aged cheese rind, like Parmesan, manchego or Asiago.
To Salt or Not to Salt
I prefer to lightly salt my stock while making it; I do it consistently so I never have to note "unsalted" on the label if I've frozen my prepared stock, and I don't have to greatly adjust the salt amounts in whatever final dish I'm creating with the stock. If you avoid salt for medical reasons or a palate preference, it's fine to leave it out.
More Vegetable Stock Options
Another thing to remember when thinking of thrifty and flavorful cooking liquids: Plenty of recipes call for draining a can of beans, vegetables, or fruit. Many have terrific flavor and body, and are worth the minimal effort of pouring into an ice tray or small container and freezing for later use.
Personal favorites include the sweet, fresh-tasting liquid from canned corn, and savory black or pinto beans, which adds body along with flavor. Any and all canned tomato liquids are also handy. If you buy seasoned ones, separating by Italian flavors and Mexican flavors before freezing — you've got an instant base for future pasta sauce or chili.