Monday, October 19, 2009

Urban Composting

We have a compost (actually two) in our Brooklyn backyard, which has been a wonderful thing not only for our vegetable garden, but also for my conscience, having been raised by a depression/World War II-era Catholic mother, who taught me that to waste anything was a sin. My environmental conscience is also gratified that I’m now contributing way less to the landfill on Staten Island.

In the winter, because of the cold temperatures, the compost doesn’t break down much and, therefore, tends to get full. A couple of winters ago I stumbled upon a wonderful way to cut down on how much I put in the compost and make fabulous stock for soups and stews. In fact, I now do this all year round, not just in the winter. It’s also a great stock-making method for city-dwellers without backyards: yields super-easy homemade stock and allows you to practice a kind of urban composting.

The basic idea is that when I am doing food prep, I save out all “good” veggies scraps (more on “good” scraps in a moment) in a gallon-size freezer bag, which I keep in the freezer until completely full. Then I throw the bag contents along with a handful of peppercorns and a couple of bay leaves in a stock pot, cover with water, and bring to a boil. I bring the temperature down, add some salt, and simmer the hell out of it (partially covered or completely uncovered if it’s a huge pot) for a couple of hours. Strain and you should have about eight cups of very rich veggie broth.

“Good” veggie scraps include: peelings from carrots, potatoes (not sweet potatoes), turnips; onion tips and unused inner layers (but not too much of the papery skins), or onions that have gone soft and aren’t great to use but are not spoiled; old garlic that’s no longer fresh but not rotten; tops and bottoms of celery; tops of leeks (very good use for them); tops of fennel; old ginger; scallions that have gone a little slimy but are not decomposed; mushroom stems; asparagus stems; chard stems; end of herbs (thyme or sage stems, rosemary stalks, wilted basil, etc.) Anything else you can think except...

I don’t use anything from the cabbage family—broccoli, Brussels sprouts, kale, cabbage, cauliflower, etc.—because they stink up the stock. Or things like lettuce and spinach, which just fall apart after that long a simmer. I do use the occasional tomato (e.g., wrinkled cherry tomatoes) but I’ve never used them in any great quantity, mostly because they get eaten long before they go south.

For you carnivores, you can also save bones in the freezer and then throw them in the stock as well—a chicken carcass or old ham bone really adds depth to the stock.

Needless to say this is NOT a delicate, well-balanced stock. I don’t even THINK about balancing it —that would defeat the whole point. (I can just see some chefs cringing if they were to read this, but I’m not a chef, I’m a home cook.) So I wouldn’t use it as a base for all soups, but for something like a hearty bean soup, it’s great. I even use it for a butternut squash bisque I make—the squash is such a dominant ingredient that the stock is really background.

Here’s the one inconvenience to compost stock: you really have to wash the vegetables whose peels you plan to use to remove residual pesticides if they’re non-organic, or to remove dirt if they’re organic. Not a huge bother, but a step that you may not ordinarily take.

That said, compost stock is incredibly easy and gratifying to make—the house/apartment smells fabulous during the hours it simmers down and there’s nothing like feeling you’ve sent one less load to the Staten Island land fill.

And here's the best part about compost stock—you don't have to buy expensive store-bought stocks anymore. I have enough stock in my freezer at this point to last me the better part of a year.

A freezer full of compost stock (in recycled cottage cheese and chinese take-out containers).

Peter emptying one of our real composts.


  1. I love this compost stock. We have loads of chicken stock in our freezer from doing the same with chicken carcasses--they do it in the commercial kitchens so why not at home? At one time we also did fishy things, using crab or crayfish shells. Talk about stinking up the house. The one thing which we really found worthwhile is clam stock, made with the water from steamed clams (clams are a big thing down here). Strain the stock to get out any grit and you have a perfect base for chowder. Which is what I just had for lunch. Andrew made it (so it tasted even better).

  2. Yes, Julia Child has a great fish stock whose base in lobster shells that I make the one or two times a year we have lobster.

  3. Of course I love the soups Therese makes with her compost stock, but I must correct one fact: there is no longer any landfill in Staten Island or anywhere elsein NYC. We now export all our non-recylable househod waste to other states for a fee. How's that for NIMBY?

  4. What a great idea! I wish I’d read this last night, before I made roasted Eastham turnips (fresh locally harvested, no wax coating) with aging sweet onions (definitely had to peel off the outer layer).

    I freeze both lobster and clam broth to use in my signature seafood barley “risotto.” I also keep the broth left after cooking dried beans and the whey when I drain yogurt—it adds a mysterious tang to soups, especially those with lots of carrots, onions, and other roots that tend to be sweet, and it’s perfect as the liquid for bread and pizza dough. But this sounds far more versatile—not just for soup, but also as a base for gravy and other sauces. Yum.