Offal of the Week: Kidney
If it's Friday, it must be Offal of the Week! Brought to you by the fearless Ryan Adams, author of the blog Nose to Tail at Home, each week we highlight a different part of the animal that you've always wanted to make, but were afraid to ask your butcher for. This week: Kidney.
Kidneys are without a doubt the least sexy cut in the offal universe. They lack the bizarreness factor of brains, the Swiss-Army-knife utility of trotters, or the oddly intimate implications of blood. About all they have going for them in a game of offal one-upsmanship is a schoolyard gross-out factor: as organs, kidneys' main purpose is to filter the blood of impurities and drain urine into the bladder. But if you happen to find yourself a good kidney source, you'll be shocked with how absolutely delicious they can be.
Extreme kidney cooking
With a lovely tender nature and a very satisfying meaty flavor, kidneys take very well to cooking methods on either extreme of the heat/time spectrum. To avoid making them tough, it's a matter of quick and high-temperature or low 'n slow: sears and sautées produce a crispy outside with a lovely pink interior, while braises tenderize the whole organ and produce hearty, rich stews.
My favorite kidney preparation is deviling them per Fergus Henderson's recipe, a straightforward and speedy recipe that involves cutting the kidneys in half, covering them in a spicy flour mixture, then sauteing them in a white hot pan. Make a quick pan sauce of chicken stock and Worcestershire, pour the whole mess over toast, and you're done. I made that recipe for my birthday breakfast last year with a glass of Black Velvet (half Guinness and half Champagne), and I can't think of a finer way to start off a special day.
A barnyard of deliciousness
If you can find calf kidneys, consider yourself lucky — they're considered the best of the bunch. But don't think for a second that lamb kidneys are worthless, and pig kidneys — though they tend to spoil even faster than calf or lamb — are very nice as well. The kidneys of an adult cow can be delicious as well, though to they do tend to be tougher than those of their other barnyard brethren, so they're best used in recipes that call for long braises.
As with many organ meats, finding top-notch kidneys in your local supermarket is pretty much not going to happen. Your best bet is a reliable butcher, or barring that, the nearest Chinese market. (If you want your kidney to have caul fat still attached to them, consider special ordering them a few days ahead of when you want to use them.)
Same-day organ meats
To make sure your first venture into kidneyville isn't your last, it's important to make sure the kidneys you're cooking with are as fresh as physically possible — it's best to use them within 24 hours of purchase, and if you find kidneys that are older than a day, keep on walking. Unlike some other organ meats, the necessity of speedy cooking isn't a matter of the meat going bad per se. Instead, it's the simple fact that because kidneys are the filters of the body, removing waste and excreting urine and ammonium, more time sitting out means more time for the urea and ammonium that hasn't been, ahem, drained, to slowly marinate the organ from the inside out. After a few days of this, the kidneys have stopped being a tender, subtly flavorful delicacy, and are instead bitter, acrid pieces of meat.
To soften the subtle uric flavor that's present in even the freshest kidneys, Hank Shaw of Hunter Angler Gardener Cook advocates soaking kidneys in milk for a few hours or overnight — it removes some of the sharpness, making them even more pleasant to the palate.
If you're feeling brave enough to serve of a plate of kidneys, here are some great recipes to get started:
The classic Steak and Kidney Pie
Pan-fried lamb's kidneys
Deviled Kidneys, similar to Fergus Henderson's method