Enter the pressure cooker. A bit dusty on a back shelf, seal ring and pressure gauge still looking serviceable, I think its time to revisit speeding up stock by intensifying the cooking, which is what pressure cookers do best. Not an original notion, pressure cooker stock seems to have quite a following on the blogs. While its no surprise to find a howto from Kuhn Rikon, the Swiss manufacturer of the worlds most high-end pressure cooker, Saveur, too, has an online article in their Test Kitchen series by Kyle Connaughten. Much more surprising, I found a discussion and instructions for making stock in the new 6 volume compendium, Modernist Cuisine: The Art and Science of Cooking, by Nathan Myhrvold et al.
In this astonishing work, which details cooking with liquid nitrogen, has pictures from within the inside of covered pots while the cooking is happening, and describes using ultrasound to "cavitate" ingredients in a liquid bath (I still do not have my head around this one), the old-fashioned pressure cooker takes center stage for meat stock. From the author who advocates cooking pastrami for 72 hours in a sous vide bath at 120 degrees, he gets the stock done in under 45 minutes!Well, could it be good? I'm curious! I've always had a healthy distaste for pressure cooker chicken dishes - closest thing in a homemade kitchen to canned chicken stew. And what about clarity? How could all that heat not cause the minute particles to be irremediably suspended in the broth? I adapted the stock discussion to beef stock, using chopped up bones, browned meat, typical stock vegetables and spices. I roughly followed the cooking directions - heat to 15 psi, lower heat and cook for 45 minutes to an hour. When I turned off the heat and allowed the cooker to come to normal pressure, the result was just what I thought. The stock smelled anything but aromalicious, and the broth looked almost milky. Could the food scientists be lacking in discrimination after all?
I re-read the manual and I have to admit, it was User Error. The most important point, and I didn't pay attention the first time around, is to allow the vessel to reach full pressure, but then to reduce the heat to low, just about a simmer.
When I repeated the procedure, both for beef and for a chicken stock, I got a really fine result. I don't think the broths would be clear enough for Thomas Keller, but they were definitely workably clear, even before straining. The key is low temp, the pressure provides process intensification, and the not insignificant benefit, significantly foreshortened cooking time.
This stock doesn't need a recipe. Whatever you normally do, you achieve the usual result, only sooner. My chicken stock was what I typically do for light soup base. I used the following - all the freshest, especially this beautiful organic half breast:
One proviso, making stock in the pressure cooker is not for big yields. It is never advisable to fill the cooker with water more than 2/3 full, or 3/4 at most. And therefore, the half breast was just the right amount for 4-6 cups of water.
So next time you think stock, think Presto - there's more to your mother-in-laws' old tool-of-choice!
