Turning Scraps Into Liquid Gold: How to Make Your Own Vegetable Stock

Turning Scraps Into Liquid Gold: How to Make Your Own Vegetable Stock
Keep a steady supply of homemade vegetable stock as a flavor-boosting secret weapon for all your favorite winter soups and stews. (Giulia Scarpaleggia)

My approach to cooking with vegetables radically changed about two years ago, during the first lockdown of the pandemic in Italy. At that time, I was three months pregnant, living next door to my parents and grandmother in the open countryside, with a job that I could already do from home. Except for not seeing friends and relatives, the only thing that changed was how we would shop. My husband Tommaso would organize weekly visits to the supermarket, shopping for the extended family, and I would take care of the fresh fruits and vegetables.

Because of the government restrictions that halted open markets for a while, our friends, who usually had a stall at the local market, started to deliver weekly produce boxes to their customers. I would draw up long lists of requests dictated by an urgency to stock the pantry and fridge with fresh produce, not knowing how the situation would evolve, and by my cravings for bitter leaves and citrus fruit.

Once a week, huge boxes of winter vegetables would be delivered to our front door: fat fennel bulbs with feathery fronds; heavy Savoy cabbages and bunches of carrots; bouquets of artichokes and bitter winter leaves. I would immediately prepare all of these fresh ingredients, as it was a grueling task to fit all the vegetables a pregnant woman craves into a standard-sized fridge.

Until that moment, I would throw all the vegetable scraps into the compost bin without a second thought, assured that they would then become fertile soil for our summer vegetable garden. But I started to notice that I was discarding a large portion of my precious bounty. It would break my heart, especially since I was dealing with vegetables so fresh, seasonal, and local.

That’s when I started to find ways to upcycle those scraps. I roasted the tough outer layers of fennel with olive oil, lemon juice, garlic, and grated Parmigiano Reggiano, and thinly sliced the outer leaves of Savoy cabbage to stew with water, olive oil, and patience. The hard stems of cavolo nero, Tuscan kale, I roughly chopped and cooked down with a couple of potatoes to become a green winter soup.

What really upped my cooking game, though, was the stock I began making from vegetable scraps. Whatever I couldn’t immediately cook into another dish—a soup, a stir-fry, or a tray of roasted vegetables—I would trim and collect in a freezer bag. Anything went: peels, outer leaves, hard stalks, ends, wilted herbs. Then when I had enough scraps, I would put all these precious bits into a large stockpot of water on the stove, and let the mixture simmer for hours, concentrating all the flavors and aromas. In the end, I would be rewarded with an umami-packed stock so rich and intense it could bring even the simplest dish to another level.

Since then, I’ve been collecting my scraps on a weekly basis, and I always have a ready supply of homemade vegetable stock in the fridge for any sudden soup cravings. What was born in my first months of pregnancy as a way to upcycle the scraps of all the vegetables I was craving is now the starting point of many dishes that are feeding my new family of three.

Ready to start channeling the Italian waste-not spirit? Here’s my method for making vegetable stock from scraps, plus a favorite winter minestrone packed with seasonal vegetables, perfect for warming up a freezing January night.

Building a Collection

Once a week, when I shop for vegetables at the market, I arrange all my purchases on my table and start sorting the produce: Some will be cooked immediately and served for lunch, others will be blanched and frozen, or just stashed in the fridge for now. I collect all the trimmings and scraps for my stock. Of course, you don’t have to do your prep all at once; you can collect your scraps over time, adding ones from what you cook each day to a plastic zip-top storage bag in the freezer until you’ve accumulated a big enough supply to make a batch of stock. Freeze them for up to about 8 months.

Almost anything goes: the tough stems of spinach, cavolo nero, and chard; the outer layers of cabbage and fennel; the hard stalks of broccoli and cauliflower; the trimmed ends of green beans and zucchini. Save your celery leaves; the peels of carrots, tomatoes, potatoes, and onions; the green ends and roots of leeks and scallions. Wilted herbs work, too: Toss in all your languishing parsley, basil, and thyme, and throw in a couple of bay leaves for good measure.

Mushrooms are a precious source of umami, adding depth of flavor to your homemade stock; save your cleaned and trimmed stems or other scraps. If you don’t happen to have mushrooms in your mix, add a handful of dried mushrooms—porcini or shiitake do nicely—to your stock when you make it.

There are just a couple of vegetables that you should avoid: Asparagus and artichokes will produce a bitter stock. Try to balance your other additions, and avoid adding too many scraps from cruciferous vegetables, such as cabbage and broccoli, as they might add a bitter or sulfurous note if they dominate the mix.

As you’ll notice, I also have a secret ingredient: a piece of Parmigiano Reggiano rind, for extra umami and saltiness—you can save these in the freezer, too. Once your stock is ready, continue the waste-not philosophy and don’t discard the rind. Cube it and add it to a soup or eat it as a snack.

Vegetable Scraps Stock

Use this waste-not vegetable stock to make risotto, start soups and stews, and poach chicken.
Use this waste-not vegetable stock to make risotto, start soups and stews, poach chicken, and more. (Giulia Scarpaleggia)
Use this waste-not vegetable stock to make risotto, start soups and stews, poach chicken, and more. (Giulia Scarpaleggia)
Makes 3 quarts
  • 6 quarts water
  • About 2 pounds mixed vegetable scraps
  • 2 ounces Parmigiano Reggiano rind
  • 1 tablespoon coarse sea salt
Fill a large stockpot with the water. Add the vegetable scraps and the Parmigiano Reggiano rind. Bring the water to a boil over medium-high heat.

When the water begins to boil, add the salt to the pot, reduce the heat to low, and simmer for three hours, until the stock has reduced to half of the initial amount.

Strain the stock into a large clean pot and season to taste with more salt. If you don’t plan to use the stock right away, let cool to room temperature, then refrigerate.

Giulia Scarpaleggia is a Tuscan-born and bred food writer, food photographer, and author of five cookbooks, including “From the Markets of Tuscany.” She is currently working on her sixth cookbook. Find her online at her blog, JulsKitchen.com
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