How to Make Vegan Stock (and Use Up Your Scraps)

I used to buy stock in those little waxed cartons, the kind that cost more than the vegetables I was putting in the soup, and then I would feel faintly guilty every time I scraped a pile of onion skins and carrot tops straight into the bin. One winter I finally did the math.

The trimmings I was throwing away every week were, more or less, a carton of stock I was paying for at the same time. That was the end of buying it.

These days I keep a fat zip-top bag in the freezer, and when it is full I have a pot of golden, savory stock for the cost of the water and twenty minutes of attention.

There are two ways I make vegan stock, and I use both depending on how organized I have been. The first is the scrap-bag method, where months of saved vegetable trimmings become broth on a lazy Sunday.

The second is a built stock, where I start with fresh vegetables on purpose because I want something cleaner and more controlled for a specific dish. Neither is hard.

But there is a real difference between a stock that tastes like a vegetable you would happily sip and a murky, bitter one, and most of that difference comes down to what you put in and how long you leave it.

Keep a scrap bag in the freezer

The single best habit I have picked up in the kitchen is the scrap bag. It is exactly what it sounds like: a freezer bag or a lidded container where clean vegetable trimmings go instead of the compost, until you have enough to make stock.

This is the trick that makes vegan stock essentially free, because you are cooking with the parts you already paid for and were about to throw out.

Here is what earns a place in my bag: onion skins and root ends, carrot peels and the leafy tops, celery butts and limp outer stalks, the dark green tops of leeks, mushroom stems, parsley and cilantro stalks, the woody ends of asparagus, fennel fronds, and the papery skins from garlic. Corn cobs after you cut the kernels off are a secret weapon for a sweet summer broth.

Tomato cores and skins add a lovely color and a rounder savory note.

The only rule is that everything going in should be clean and not actually rotten. A wrinkled carrot or a slightly tired stick of celery is fine; the whole point is rescuing produce on its way out.

But slimy, moldy, or genuinely spoiled bits do not magically become good in a pot, they just make a sad stock. Give everything a rinse before it goes in the bag, since you will not be peeling it later.

When the bag is full, you tip it straight into a pot frozen, no thawing, and the ice crystals that formed in the freezer actually help rupture the cell walls so the scraps give up their flavor faster.

One honest note from experience: the first few scrap stocks I made were a little flat, because a random bag of trimmings is unbalanced by nature. If your bag is all onion skins and parsley stalks one week, the broth will skew sharp and herby.

I now keep half an eye on the mix as I fill the bag, making sure there is a decent ratio of carrot and celery to the alliums, and I will throw in a couple of fresh carrots and an onion at simmer time if the bag looks thin on the sweet, rounding vegetables. A scrap bag is a starting point, not a straitjacket.

What to leave out (the bitter brassicas)

Photo: İdil Ceren Çelikler / Pexels

This is the part that turns a lot of first-time stock into something you quietly pour down the drain. Not every scrap belongs in stock, and the worst offenders are the brassicas.

That means cabbage, broccoli stalks, cauliflower cores and leaves, kale and collard stems, Brussels sprout trimmings, and broccoli rabe. They are full of sulfur compounds that smell fine when you roast them but turn aggressively bitter and faintly eggy when you simmer them in water.

A handful of broccoli stems can wreck an entire pot, and once it is in there, you cannot fish the flavor back out.

A few other things I keep out or use sparingly. Beet skins will stain your whole stock magenta, which is fine if you want that and a disaster if you do not.

Too many potato peels make the stock cloudy and a little gluey from the starch, so I add only a few. Artichoke trimmings turn things bitter. Bell pepper guts can go acidic and overpowering in quantity.

And go easy on anything intensely flavored on its own, like a pile of garlic skins or hot pepper bits, unless you specifically want a garlicky or spicy broth. If you are ever unsure whether an ingredient even counts as vegan in the first place, our vegan ingredient checker and the Is It Vegan database will settle it in a few seconds.

The built stock: when you want control

Sometimes I do not want a mystery-bag broth. If I am making a clear soup, a risotto, or a sauce where the stock is the main flavor, I want to know exactly what is in it. That is when I build a stock from fresh vegetables on purpose.

The classic base, the one the French call mirepoix, is two parts onion, one part carrot, one part celery, and you can lean on that ratio forever and never go wrong.

My non-negotiables for a built stock are onions left in their skins for color, carrots for a gentle sweetness, celery for that clean savory edge, a couple of smashed garlic cloves, and a handful of mushrooms for meatiness. Then I add aromatics: parsley stalks, a few sprigs of thyme, a bay leaf, and a small fistful of black peppercorns.

I almost always char the onion halves cut-side down in the dry pot first, because that browning is where a built stock gets its color and a layer of depth you simply cannot get from raw vegetables in water. The recipe card above is exactly the version I make most often.

Simmer it gently, and not for too long

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If you remember one thing about timing, make it this: vegetable stock does not want a long cook. Meat and bone stocks need hours to break down collagen, and people assume vegetables work the same way. They do not.

Vegetables surrender their flavor in well under an hour, and after that you are not extracting more goodness, you are pulling tired, bitter, flat notes out of spent scraps. Forty-five minutes to an hour is the whole window.

I set a timer for 45 minutes, taste, and pull it off when it tastes like something I would sip from a mug.

Keep it at a gentle simmer, with just a few lazy bubbles breaking the surface, never a rolling boil. A hard boil churns the vegetables apart and gives you a cloudy, muddy stock instead of a clear golden one.

Leave the lid off or cracked so a little water evaporates and the flavor concentrates. In the first ten minutes, skim off any gray foam that rises, since that scum is what clouds the finished broth.

And salt at the very end, not the start, so you stay in control of the final seasoning, which matters a lot if you are going to reduce the stock down later for a sauce or vegan gravy.

Depth boosters: miso, nooch, and umami

A meat stock tastes rich because bones release gelatin and savory glutamates. Vegan stock has to get that depth elsewhere, and the good news is there are a handful of pantry ingredients that do the job beautifully. Umami is the lever you are pulling, and once you know which ones to reach for, your stock stops tasting thin.

My top three: white or yellow miso, whisked into a ladle of warm stock at the very end and stirred back in off the heat, which adds a deep savory roundness without a fishy or meaty note. Nutritional yeast, a tablespoon stirred in, brings a roasted, almost cheesy savoriness. And dried mushrooms, a couple of shiitake or porcini dropped into the pot, are pure concentrated umami.

A splash of soy sauce or tamari does similar work, as does a spoon of tomato paste cooked until it darkens. For a clean, briny backbone, a small piece of dried kombu seaweed simmered gently is the classic move from Japanese dashi, though pull it out after about twenty minutes before it turns the stock slimy.

If you want to go deeper on the savory-yeast side of things, the miso guide is worth a read; fermented soy is doing a lot of quiet work in good vegan cooking. Mushrooms in particular are loaded with natural glutamates, the same savory compound that the umami taste is built around, which is why a mushroom-forward stock reads as so satisfyingly meaty.

Strain, then freeze in cubes

Once the stock tastes right, strain it through a fine-mesh sieve set over a big bowl, pressing the solids gently with the back of a ladle to get the last of the flavorful liquid. The spent vegetables have given everything they have, so they go to the compost now, not back in the pot.

If you want a truly clear stock for a delicate soup, line the sieve with a piece of cheesecloth or a clean thin tea towel.

Cool the stock fully before it goes anywhere near the fridge or freezer, ideally by setting the pot in a sink of cold water to speed it along. In the fridge it keeps about five days in a sealed jar.

For longer, freezing is where stock really pays you back. I freeze it two ways.

The first is ice cube trays, which give you little flavor bombs, roughly two tablespoons each, perfect for deglazing a pan, loosening a sauce, or cooking a pot of grains in something better than water. Once frozen, pop the cubes into a labeled bag so the tray is free again.

The second is in two-cup portions in flat freezer bags or containers for full soups and stews. Frozen stock keeps its flavor for about three months and is genuinely good for six.

Label everything with the date, because a year from now an unlabeled brown brick in the freezer is a mystery nobody wants to solve.

Put your stock to work

A jar of homemade stock quietly improves almost everything you cook. It is the obvious base for soups, but I reach for it far more often as a swap for plain water: simmering a pot of lentils or rice, building the liquid for a risotto, deglazing a pan of roasted vegetables, loosening a stew, or thinning a sauce that has gone too thick.

Anywhere a recipe says water and you want more flavor, stock is the upgrade. A scrap-bag stock is a little wilder and more rustic, great for hearty soups and braises, while a clean built stock shines in anything where you actually taste the broth.

So here is the whole thing, start to finish. Keep a scrap bag in the freezer and feed it your onion skins, carrot tops, and mushroom stems. Leave the bitter brassicas out.

Simmer gently for 45 minutes, no longer, salt at the end, and lean on miso, nooch, and dried mushrooms for depth. Strain, cool, and freeze it in cubes.

You will never look at a carton of bought stock the same way again, and your soups will quietly get better for it. The best stock is the one made from what you already had, and now it costs you nothing but a little attention on a slow afternoon.