Don't Throw Away Your Vegetable Scraps: Use Them In Stocks And Broth

It's no secret that vegetable scraps are a frugal, zero-waste tool for making excellent homemade soups. But what vegetables should you use for stocks and broths? Which should you avoid? To answer these questions, Food Republic turned to Sarah Hill, recipe developer and food blogger at Real Food with Sarah.

"Great scraps for broth include onion skins, carrot tops, celery leaves, mushroom stems, leek greens, and herbs (like thyme and rosemary)," Hill informed us. These common kitchen cast-offs may be inedible in most recipes, but that doesn't mean they lack flavor. While sauteing onion skins and celery leaves only leaves you with an oily mush, boiling them extracts all their flavor without needing to consume them directly. And since vegetables don't have any collagen to break down, like bones, you'll only need to simmer them for an hour to bleed all their flavor into the water.

"I don't recommend cruciferous vegetables like cabbage, Brussels sprouts, or broccoli, as they can turn the broth bitter," Hill explained. These veggies are high in glucosinolates, a sulfurous, bitter compound you must expose to dry heat to break down properly. Adding cruciferous vegetables is a common mistake everyone makes when cooking homemade broth, so take Hill's advice and avoid them entirely. But when you work with the right vegetables, there's a whole world of tricks you can use to enhance their flavor and make storage much easier.

If you don't cook often, it's difficult to build up enough vegetable scraps for stock before they expire. "I keep a bag of veggie scraps in my freezer to make both chicken and beef stock," Sarah Hill explained. Since the scraps' textures don't matter, there's nothing wrong with freezing them to preserve their natural flavors and ensure they don't spoil.

But if you're using fresh scraps or ones taken from your fridge, you can enhance their flavors even more. "Roasting vegetables before adding them to the broth can deepen the flavor, but I don't find it necessary," said Hill. Much like when making more flavorful chicken broth, roasting caramelizes the sugars in vegetable scraps, adding roasted notes to your stock to upgrade its savoriness. However, this step is 100% optional, and you should only use it for fleshier scraps like carrot skins, extra onion, or celery hearts. If you try to roast papery onion skins or carrot leaves, you'll likely just burn them and ruin their flavor.

When it comes to storing stock, you have several options. The ice cube tray hack gives you convenient, small portions of broth or stock to work with, perfect for enhancing the flavors of meaty soups and sauces. Conversely, you can freeze one-cup portions in zip-top bags, making it easy to assemble quick weeknight soups at your leisure. While vegetable stock may only be good for up to one week in the fridge, freezing it extends that time to six months.