I remembered where I saw this information. It's the July Aug CI and has the numbers Charlie
mentioned along with the size of the grain.
Published July 1, 2012. From Cook's Illustrated.
Here's a handy guide for cooking this nutty-flavored grain.
Bulgur is made from parboiled or steamed wheat kernels/berries that are then dried, partially stripped of their outer bran layer, and coarsely ground. Don’t confuse it with cracked wheat, which is not parcooked. Most recipes using bulgur call for medium grind, which we rinse to remove any detritus and simply soak in water or another liquid until tender.
Bulgur is sold in four numbered grind sizes, but bulk bins and many U.S. brands often don’t identify the grind by number or provide a description of the size—and when they do, they’re inconsistent. This guide should help.
Find the Right Grind
#1 FINE The smallest grind, similar to couscous in appearance.
#2 MEDIUM The most widely available size in bulk bins and supermarket brands, with grains about the size of sesame seeds or kosher salt.
#3 COARSE Slightly coarser than medium grind but interchangable with it in recipes.
#4 EXTRA-COARSE Nearly whole kernels that closely resemble steel-cut oats. Used in pilaf and stuffing.
A Happy Medium
Most recipes call for medium-grind grains.