In the test kitchen, a ruler is a crucial tool. When I’m testing a recipe, and it says to cut something like a potato into 1/2-inch dice, I actually whip out the ruler and make sure my dice is on the mark. That may sound obsessive, but size affects cooking time, and in the recipe testing business, you’ve got to follow a recipe to the letter. There are too many other variables that play into cooking—different brands of ingredients, pots, stoves, etc.—to be haphazard about the things you can control, like dice size.
At home, I’m a lot more laid back about it. That’s where I use my “finger ruler.” I learned this tip in culinary school from Chinese Master Chef Shirley Cheng, who was lengendary for her astonishing skill at boning a whole chicken with a cleaver in record time. In class one day, I needed to measure something—I can’t remember what—and she waggled the tip of her pinky finger at me, saying, “Use your Chinese finger ruler!”
It turns out that many of us humans have pinky tips that are all around the same length, and handily, that length is about 1 inch. I mentioned this one day in the test kitchen at a tasting, and everyone immediately wanted to measure their pinkies. Only one of us had a pinky tip that wasn’t very close to an inch, but her ring finger tip was.
The Chinese finger ruler trick is useful outside the kitchen, too. I’ve used it to estimate length of all sorts of things, from deck screws to yarn. So the next time you’ve got a real ruler out, use it to find your finger ruler—you’ll be surprised how often it comes in handy.