Kitchen Basics Kid approved
The 5-Ingredient Weeknight Tomato Sauce
Whole canned tomatoes crushed by hand, simmered with butter, an onion and garlic until it tastes like it took all day.
Next Door Chef nextdoorchef.com/recipes/vegetable-scrap-stock
Kitchen Basics Uses it up
Vegetable Scrap Stock (Stop Buying Broth)
Fill a freezer bag with onion skins, carrot ends, and mushroom stems, then turn it into 8 cups of stock for about a dime a cup.
A carton of broth runs three to five dollars and tastes mostly like salt and yeast extract. The scraps you throw out every week make something better for about a dime a cup, and the only real work is remembering to keep a bag in the freezer.
What the bag is for
You are not making a special trip or buying anything. Onion skins, carrot peels, celery butts, leek greens, mushroom stems, corn cobs, herb stems: all of it goes into one gallon bag as you cook, and when the bag is full you have a batch. That is the whole system. It turns the most annoying part of cooking, the pile of trimmings on the cutting board, into the thing that makes next week’s soup taste like something.
Three rules keep the pot honest. Brassicas, beets, and potato peels never go in the bag. The pot never boils, it sits at a lazy simmer where a bubble breaks every second or two. And it never gets salted, because stock is an ingredient and you have no idea yet how far you will reduce it.
An hour of doing nothing gets you 8 cups of deep gold stock. Freeze it flat, and pull a bag out on the night you need dinner to happen fast.
- Prep
- 5 min
- Cook
- 60 min
- Total
- 65 min
- Serves
- 8
- Level
- Easy
How to make it
-
Start the bag today
Put a gallon freezer bag in the door of your freezer and feed it every time you cook. Onion and shallot skins and root ends, carrot peels and tops, celery butts and leaves, leek greens, mushroom stems, fennel fronds, garlic skins, corn cobs, tomato cores, parsley and thyme stems, green onion roots. Rinse anything dirty before it goes in, because grit in the bag is grit in the pot. When the bag is full and packed down it is roughly 8 cups, which is one batch.
Chef's note. Freezing actually helps. Ice crystals rupture the cell walls, so the scraps give up their flavor faster than fresh ones would.
-
Keep three things out
Brassicas, beets, and potato peels stay out of the bag, and each one ruins a pot in a different way. Broccoli stalks, cauliflower cores, cabbage, kale ribs, and brussels sprout trimmings turn sulfurous and cabbagey over a long simmer. Beets and beet greens dye the whole batch magenta so it fights every dish you use it in. Potato peels shed starch that clouds the stock and leaves it slightly gluey.
Chef's note. Also skip anything moldy, slimy, or sour. Stock does not fix a bad vegetable, it just spreads it across 8 cups.
-
Start in cold water
Dump the frozen scraps into the pot with the onion, bay, peppercorns, and parsley stems, then add cold water to cover by about an inch. Cold start matters: as the water heats slowly, soluble flavor compounds come out gradually and the stray proteins and fine solids coagulate and float to the top where you can lift them off. Boiling water poured over the top drives those particles into suspension immediately and you can never get them back out.
-
Bring it to a bare simmer
Heat over medium until you see the first real bubbles, then drop to low. You are aiming for about 190°F to 200°F, which looks like a bubble breaking the surface every second or two and a wisp of steam, not a rolling churn. If the surface is moving fast enough to spin a bay leaf around, the heat is too high.
Chef's note. A lid tilted halfway on holds the temperature steady on a weak burner without letting the pot climb to a boil.
-
Skim the first ten minutes
Foam and gray scum will rise as it comes up to temperature. Lift it off with a ladle or a spoon and discard it. That foam is coagulated protein and fine plant debris, and if you leave it it eventually breaks apart and clouds the stock. After the first ten minutes it mostly stops forming and you can walk away.
-
Simmer one hour, then stop
Vegetable stock is done in an hour. Unlike bone stock, there is no collagen to convert, so nothing improves after the soluble flavor is out, and long cooking starts pulling bitter compounds from the peels and stems. It is ready when the liquid is deep gold, the carrot pieces have gone pale and limp, and a spoonful tastes clearly of vegetables rather than warm water.
-
Strain gently and do not press
Ladle the stock through a fine-mesh strainer set over a large bowl, then let the last of it drip through on its own. Resist the urge to press the solids with a spoon. Pressing forces fine pulp through the mesh, which turns clear stock cloudy and squeezes out the bitter, tannic liquid that was staying put.
-
Salt the dish, not the stock
Leave it unsalted. Stock is an ingredient, and half the time you will reduce it later to concentrate a sauce or a risotto. Salt does not evaporate, so a stock salted to a pleasant 1 percent becomes a punishing 2 percent when you cook it down by half. Season the finished dish instead, where you can taste what you are actually eating.
-
Cool fast, then portion
Set the bowl in a sink of ice water and stir every few minutes until it is barely warm, about 20 minutes. Getting it out of the 40°F to 140°F range quickly is a real food safety step, not fussiness, since a warm pot of stock left on the counter overnight is close to a laboratory growth medium. Then portion it into containers or freezer bags laid flat.
Chef's note. Freeze 2 cups of it in an ice cube tray. Two cubes deglaze a pan, four finish a pot of rice.
Why this works
Vegetable stock is a straight extraction: hot water pulling out sugars, amino acids, and aromatic compounds that were locked in cell walls. That is why the temperature matters more than the time. At a bare simmer around 195°F the water moves slowly enough that fine particles settle and fat stays in a layer on top where you can skim it, but a hard boil churns the pot, shears solids into pieces small enough to stay suspended, and mechanically beats fat into the liquid so it emulsifies into a cloudy, slightly greasy broth. The heavy hitters in the bag are onion skins for color and sweetness, mushroom stems and tomato cores for glutamate, which is what makes a meatless stock taste savory instead of thin, and corn cobs for body and a background sweetness. Brassicas break down into sulfur compounds under long heat, which is the same chemistry that makes overcooked cabbage smell the way it does, and there is no rescuing a pot once it happens.
Swap what you do not have
- No freezer bag going yet? A single onion, two carrots, two celery ribs, and a handful of mushrooms will make a solid 8 cups tonight.
- Want it deeper and browner? Roast the scraps on a sheet pan at 425°F for 25 minutes first. Browning builds Maillard flavor the raw version does not have.
- Add a 3-inch piece of kombu or a dried shiitake for a big glutamate boost, which makes vegetarian soups taste like they had chicken stock in them.
- Chicken carcass in the freezer? Add it to the same pot and simmer 2 hours instead of 1. Bones need the extra time to give up their collagen.
- Corn cobs and parmesan rinds are the two best things you can add. A single rind turns this into the base of a minestrone.
Make ahead
The whole point is make-ahead. Scraps keep in the freezer bag for 3 months, and the finished stock keeps 6 months frozen. Run a batch whenever the bag fills up rather than when you need stock.
Leftovers and storage
Refrigerate up to 5 days or freeze up to 6 months. Freeze it flat in quart bags so it thaws in minutes under warm water, and leave an inch of headspace because liquid expands as it freezes.
Per serving, estimated: 15 cal 1g protein 3g carbs 0g fat
Questions people ask
How long do vegetable scraps last in the freezer?
About 3 months in a sealed bag before they start to taste flat and freezer-burned. Squeeze the air out each time you add to the bag, because it is air contact that dulls them. Label the bag with the date you started it.
Do I need to thaw the scraps first?
No, go straight from freezer to pot. Frozen scraps actually extract better, since ice crystals rupture cell walls during freezing and release the contents faster once heated. Just add a few extra minutes to reach a simmer.
Why is my vegetable stock bitter?
Usually it simmered too long or the solids got pressed at the strainer. Vegetable stock is finished at 45 to 60 minutes, and past that the peels and stems start releasing bitter compounds. Squeezing the spent scraps does the same thing in one squeeze.
Can I use vegetable scrap broth in place of store-bought broth?
Yes, one for one, with one adjustment: yours has no salt in it. Commercial broth is heavily salted, so taste your dish and add salt where the recipe assumed the broth was bringing it.
Recipe by Sammy Panice, the Next Door Chef. More at nextdoorchef.com
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