Before I attended culinary school, I thought kitchen scales were just for calorie-counters. But on Day One of my course, that myth was debunked by the giant, old-school but highly accurate scale plunked down on the stainless steel counter in front of me. I was told to use it for everything. So I did. And I grew to love it.
The fact is that ingredients are most accurately measured in weight rather than volume. Think about three cups of cubed potatoes: imagine how much that measurement can vary depending on how the cubes are cut and packed. While your hash browns might not suffer for lack of accuracy, baking is another matter. How a cup of flour is measured is measured can be the difference between a fallen, but not collapsed soufflé, for example.
If you just are a stickler for accuracy, you will appreciate how a scale enables you to measure perfectly every time. For those recipes without alternate measurements in weight, you can refer to a resource like this which tells you what common foods measure out to be in weight and in volume. Some you might even memorize: for example, chefs know that a cup of granulated sugar is 200 grams. I have Clothilde of Chocolate & Zucchini's Conversions and Equivalents page of common ingredients bookmarked and refer to it often.
If you like speed, you'll enjoy the way a scale allows you to just dump ingredients into a bowl until the magic number is reached. No swiping with a knife to level a cup of sugar, or eye-balling a cube of butter to make sure you slice along the tablespoon marker correctly.
Of course, for regular old run-of-the-mill cooking, you don't need a scale. You know we're not in the business here of telling you to buy pricey gadgets. However, if you use old recipes, use foreign recipes, develop recipes, adapt recipes, or have reason to make a recipe many times and need the product to be the same each time (like Faith's wedding cakes, for example), a scale can be anywhere from helpful to absolutely essential.
There are two commonly used types of scales: mechanical and digital.
Mechanical scales are the old-school kind I used in culinary school: they use a spring to measure the compression under weight of the item being weighed (remember physics 101?) The problem with this method is that these scales, unless very highly tuned (read, expensive) will deteriorate over time. I used something like this Heavy Duty Platform Scale, but at $400, I doubt many home cooks would consider it. There are inexpensive mechanical scales, like this $4 job, but they really aren't worth considering.
Since I work in two kitchens, I have two scales. Both are small, digital, and made by Salter. The reason I like digital is because they are light and very accurate and they give a reading almost instantly. Most come with a tare feature which lets you add your own container then zero-out the reading so that you can measure, say, a bowlful of sugar or flour without having to subtract the weight of the bowl yourself.
The first is square, all stainless and has an 11 pound limit. It's design is more sleek, so it's easier to toss in the cabinet but be careful, it's still a scale.
The second is round, with a stainless steel weighing surface and a black plastic face. It has a limit of 5 pounds, which is more than enough. On the rare occasion that I'm measuring something heavier, I do it in batches, if possible.
• Buy the Square Stainless Steel Electronic Kitchen Scale (model #1004) by Slater (Amazon, $38.95)
• Buy the Round Stainless Steel Electronic Kitchen Scale (model #1015) by Salter (Amazon, $24.95)