Save Those Crustacean Shells to Make a Sauce Base

This weekend, my boyfriend and I made crab sauce — a red sauce full of delicious crab. There were huge pieces of Dungeness meat, yes, but the true hero of the sauce were the crab shells, which we mashed and simmered with onion and fennel to make an intensely crabby base.

I am not saying the meat was not an important part of the final product, but meat is tossed in at the last minute — so as to prevent the delicate protein from overcooking in a pot of hot, acidic, crushed tomatoes — and doesn’t have time to impart much flavour. And while a “normal” marinara punctuated with crab meat would still be quite delicious, a crab-flavored sauce punctuated with crab meat is even better.

We used Hank Shaw’s crab sauce recipe, but the method used to make the base could be applied to any sauce that needs a hit of seafood flavour, and you can use almost any crustacean shell to make it. Prawn, lobster, crawfish and whatever crab is local to your waters would all work deliciously; you just need a heavy wooden spoon (or metal potato masher).

Mash the shells with sautéed onion, garlic and herbs, simmer, then strain and add to your sauce to taste. Hank’s base calls for a little ouzo, which is not a bad idea; you could also certainly use some wine or the vermouth that’s been hanging out in your fridge for the last couple of months.

How many shells do you need? Not that many. We made our base with three Dungeness shells, which resulted in about a quart of base, only half of which we used for a big batch of sauce. The base does freeze quite well however, so it may be worth saving your shells (also in the freezer) until you have at least three crab, or six lobster, or 20 or so prawns to make a large amount all at once. (It does kind of stink up the kitchen.) You can also combine shells for a multi-crustacean base — an idea which I think is good. To make this flavour-packed shell water, you will need:

• 3 tablespoons olive oil
• 1 onion, diced
• Crustacean shells (About 3 crab, 6 lobster, 20 prawns or a mixture)
• 4 cloves garlic, minced
• A 3-4 bay leaves, the tops from a bulb of fennel or a few whole sprigs of any other herbs you think would taste good with seafood
• 1/2 cup some sort of alcohol, be that wine, vermouth or ouzo

Heat the oil in a large stock pot over medium-high heat, add the onion and cook until translucent. Add the shells and garlic and mash the former up real good with a big wooden spoon or a potato masher. Cook for about five minutes, then add the bay leaves, fennel and/or herbs, as well as whatever alcohol you’ve chosen. Add enough water to cover everything by about 2 cm, then simmer for an hour.

Strain out the large solids through a colander, then do a fine strain through a cheese cloth- or paper towel-lined sieve. Next time you make a sauce that could benefit from some oceanic flavour, add a cup or two of your base. If sauce-prep isn’t immanent, simply freeze the base into giant cubes or small soup containers, then toss them into future sauces as needed.