At the risk of alienating readers whose childhood memories of math and science classes rank right up there with minor surgery, today we’re going to tackle units of measurement. Whether you’re weighing out specialty grains, calculating pre-boil volume, or timing the mash, measurement is at the heart of brewing. You simply can’t make good beer without it. But you don’t need a degree in astrophysics, just a little patience and a calculator or smartphone.
There are two primary systems of measurement you’ll come across as a brewer: metric and U.S. Customary. Now, a few brewers in Commonwealth countries might work in Imperial units, which are similar to U.S. Customary. But since equipment and ingredients outside the United States are sold almost exclusively in metric, we won’t discuss Imperial units. Just be aware that an Imperial gallon and a U.S. gallon are different, just as an Imperial pint and a U.S. pint are not the same thing.
Metric
The metric system is favored by most of the world’s governments and industries, and for good reason. All derivative quantities are expressed in terms of a base quantity and some multiple of 10. So, you have your meter, which consists of 10 decimeters, 100 centimeters, or 1,000 millimeters. Similarly, 10 meters is 1 decameter, 100 meters is 1 hectometer, and 1,000 meters is 1 kilometer. It’s nice and easy: All you have to do is move the decimal point around to switch between smaller and larger quantities.