If you're serious about baking and pizza-making, a scale is a worthwhile investment. The problem with measuring flour by volume is that as I mentioned last week, it's amazingly inaccurate. A cup of flour can weigh anywhere from 4 to 6 ounces depending on how you fluff it or pack it, and even the experts disagree on how much a cup of flour is supposed to weigh.
By measuring by weight, you're guaranteed accuracy, no matter how you pack the flour. Weighing your ingredients directly in the mixing bowl also means there are no extra measuring cups to wash. (Which is always a good thing in my book.)
To use a scale correctly, you need to understand the tare function. Years ago, when my job included buying material by weight, one of my suppliers told me that we didn't pay him enough—his measurements were different from ours. I asked his material handler to show me how he weighed the material. He got on the fork lift, picked up the box of material, drove onto the scale and wrote down the weight on a ledger. I said, "Fine, I'll pay your weight, but you've got to give me the forklift, the box, and the employee you just weighed along with it."
Moral of the story: if you don't tare your scale, your measurements can be very, very wrong.
The tare function (sometimes called the "zero" function) is what allows you, without any pesky math, to calibrate the scale so that it doesn't take into account any of the things you don't want to be measuring. Usually, that's the weight of the bowl, and/or the weight of whatever ingredients you've already added to it.
There are two ways to use the tare function to your advantage.
Find a bowl that is large enough to hold your ingredients individually, and put that on the scale. My little bowl weighs 3 7/8 ounces.
Press the tare button (on my scale, it's the "zero" button), and the weight will reset to zero, so you can begin weighing ingredients without worrying about the container weight.
Add your ingredients to the bowl until you reach the correct weight. If you go over the correct weight, just remove some until you get back down to the proper weight.
Dump those ingredients into your work bowl, and continue with the rest of the ingredients. If anyone doubts the range of weights you can get by measuring, here's the same flour and the same 1/2 cup measuring cup. Above, it weighted 2 1/4 ounces, and here it's a whopping 2 7/8 ounces.
It's a good practice to press the tare button each time you put the empty bowl on the scale, particularly if any of your ingredients might be clinging to the bowl. Keep in mind that the ingredients that land on the scale platform are also being weighed, so keep the scale clean.
Put your work bowl on the scale, press the tare button to zero the scale and add your first ingredient until you reach the proper weight. Then press the tare button again to zero the scale and add the second ingredient. This method is a little trickier in that it's slightly harder to remove ingredients when you've piled them on top of one another. So the key is to get close to the correct weight, adding slowly, and wait for the scale to settle and display the correct weight before you add more.
With the second method, you've streamlined your cleanup down to a single bowl!