Recently, a question was presented to me. Why do we use different measures for liquid and for dry product? Well, the short answer is because they are different things that measure differently. Here's the ugly truth though. Neither one is entirely accurate. In a kitchen, weight is a more accurate measure. Especially with dry goods. But who in the world keeps a scale in their kitchen? Very few.
So here's the skinny: Liquids and dry goods measure differently because they have different masses. So 8 oz is a cup in liquid, but pour it into a dry measure cup and you will come up short; because the dry measure cup has to account for things with more mass than a liquid. Cups vs ounces, but a pint is a pound the world around.
I encourage everyone to try this experiment in their home. Pour a cup of water into a liquid measure, then pour it to a dry measure of the same amount and see what you get. Then do the reverse, with flour or sugar, keep in mind if you use flour you have to level and tap it down. Sugar doesn't have that issue, since it is granulated.
Well that is my kitchen physics lesson of the day.
"Some rise by sin, some by virtue fall" ---Measure for Measure, Shakespeare
