Today's lesson is what to do with all of those leftover vegetable trimmings. I had tossed everything into a bowl and was about to tip out my blanching water down the drain, when I realized I had the perfect base for vegetable stock. I also had a lot of Parmesan rinds in the freezer. I made vegetable stock as well as sweet corn stock, both of which are incredibly easy and only take a few active minutes, and then a lot of simmering. Parmesan makes a really great stock, especially if you are looking for a rich substitute for meat stock. Because it contains large quantities of (naturally occurring) MSG, it provides a lot of "meaty" body and flavor. You can purchase Parmesan rinds at Whole Foods, or you can just save them in the freezer as you get to the end of your grating Parmesan. You could probably use the leftover rinds of any kind of hard grating cheese, or you can leave it out altogether. Dried porcini mushrooms are available in any gourmet store, but they are probably least expensive at Trader Joe's. I think they're around $4 a pack - compared to $12 and more at specialty stores.
One of the great tricks I've learned for freezing liquids is using silicone baking utensils. They are nice because they can be washed in the dishwasher, and it is really easy to pop out the frozen blocks, unlike traditional ice cube trays. It also makes measuring a breeze - the packaging materials will state the volume of each cup - most muffin cups are 2/3 cup, mini loaf pans are - if my memory serves - about 1 1/3 cups, etc. You can find them at Target for around $9 a piece - muffin pan (pictured above, with parm & veg stock), mini loaf pans (pictured at top of post, with sweet corn stock), etc. I also bought these pretty cool ice cube trays at Bed Bath & Beyond the other day, which make perfectly square cubes - cool for freezing stock or for making cocktails look extra purdy (cubes pictured below). Be sure to store your silicone trays in a clean, dry place - everything sticks to them - dust, cat hair, lint, etc.
There aren't really measurements for making stock, I hope this doesn't cause stress. I use an 8 quart All Clad stock pot for stock making, and usually start with it full to about 3 inches from the top.
Basic Vegetable Stock, with Parmesan
Vegetable trimmings. I probably started with a pound of trimmings
1/2 pound Parmesan rinds
2 ounces dried porcini mushrooms
leftover water from blanching veggies, plus more - I had about 2 cups of water from this batch (which involved steaming only), and added about 5 quarts of water?
Bring everything to a boil, then turn heat down and simmer for 4-6 hours. Strain the stock into a bowl and then refrigerate overnight, just in case there is fat leftover from the Parm. I froze the stock in silicon muffin pans and mini-loaf pans, and then vacuum sealed the frozen disks and blocks, so that I have the stock in various amounts. Ice cube trays also work nicely.
Sweet Corn Stock
Corn cobs with the kernels cut off
Leftover water from blanching corn - this time I didn't add water, as I already had a lot of it, probably about 6 quarts.
"Milk" the cobs into the pot of water by scraping them with the back of a knife, and place the cobs into the water. Bring to a boil, then reduce the heat and simmer for 4-6 hours, then remove the corn cobs. Strain the stock through a fine mesh sieve and freeze. There is so much residual sugar in this stock that it is sticky, seriously. I froze this as above - in silicon muffin pans.