Kitchen Scale

A kitchen scale is an essential tool in every kitchen. Most American kitchens have a set of measuring cups, but don't have a kitchen scale. Is this a gadget that only perfectionist chefs and constant bakers need? No, give a good scale a try and you'll find that it's a better and faster way to cook. Is this a gadget that only perfectionist chefs and constant bakers need? No, give a good scale a try and you'll find that it's a better and faster way to cook.

 A lot of people know that you should use a scale when baking. Baking is probably the only form of cooking that I can say is a science without people arguing with me. (Try saying "stir-fry is a science" or "candy-making is a science" without having the science vs. art discussion.) This is because just about every cookbook that covers baking discusses the importance of balancing acids and bases and precise measurements are of paramount importance when trying to transform a wet glob of batter into a glorious, fluffy dessert. To get precise measurements, we are told to toss out the measuring cups and use a kitchen scale. But is baking the only reason to use a scale?

Precision is how repeatable a measurement is. For example, if we measured a cup of all-purpose flour in a 1 cup (8 ounces) dry measuring cup, we expect the mass of the flour to be 125 grams. Assuming that the dry measuring cup is constructed to strict standards, the cup is accurate but not precise. Every time flour is measured, it is a bit more or a bit less than 125 g. How tightly packed the flour is, whether it has been recently sifted, if we scooped the flour or spooned it, all make an impact to the repeatability or precision of using a cup as a measuring device.

On the other hand, a scale is precise (and accurate if calibrated). When a cup of flour is weighed on a scale, it is possible to add or take away flour until the scale registers 125 g. The precision of the scale is dependent on how easy it is to read the scale. In baking, using a scale to measure all the ingredients will ensure that you are following the recipe correctly (at least in terms of the proportions of ingredients). Using measuring cups could result in having a little more flour than leavening, etc.is a big reason why I use a scale. When I've figured out how much sugar to put into a recipe or how much butter is needed, using a scale means that next time I make the recipe it will have a greater chance of ending up exactly the same as I made it last time.
If precision and repeatability aren't motivating factors for getting a scale (and for most home chefs they don't sound too compelling), here's a good one: No more scooping with a measuring cup and then leveling the top with a straight edge. Simply pour into a bowl set on the scale and stop at the desired point. With fast response digital scales, the weight display is updated fast enough that you can pour until you hit the desired value. Then you can zero out the scale and measure your next ingredient Less mess to clean up, faster measuring, and more precision. There are no drawbacks to using a kitchen scale (except perhaps the initial impact to your wallet).

Types of Scales 
There are three main types of scales available for use in the kitchen. Balance, mechanical/spring, and digital. The three operate on different principals for measuring weight. The balance operates by performing comparisons between known masses and the object to be weighed. (Technically, a balance determines mass not weight and is the only type of scale that will work properly if you plan to cook on the moon. The balance in all other disciplines is considered separate from a scale, but in cooking we lump the two together.) The problem with the balance is that it only reports if the object you are measuring is greater or less than the known mass. For example, when using a balance to measure a cup of flour, 125 g of known mass is placed on one side of the balance while flour is placed on the other side until the mass on both sides are in balance. 

A beam balance has a beam with adjustable masses that move along the beam to increase torque applied to counteract the torque on the other end of the beam from the weight of the object being measured. (Exactly like the physician's scale at your doctor's office.) In general, a good balance is extremely accurate and can be extremely precise, but no matter how skilled the operator of the balance is, I feel it's a bit slow for use in the kitchen. 

                                                                  

Mechanical scales use a platform mounted on a heavy spring to measure weight. An ideal spring compresses proportionally to the force applied to it. This means the weight placed on the platform is directly related to the distance that the platform moves down. The problem is that in actuality, springs aren't ideal.

For the most part, they do exhibit the property of linear compression, but they also may change compression rates over time, may not return to their original length, and sometimes even break. Also, another problem with springs is that small quantities are harder to measure than large quantities. For example, if a scale is designed to measure up to 5 lbs. then then measuring one ounce of something will be more difficult than one pound. This is because the small amount of movement in the spring caused by one ounce will be difficult to detect because the scale is designed to move evenly throughout the whole five pounds. However, high quality mechanical scales can be quite precise, but they also carry a hefty price tag.

A good digital scale provides easy to read measurements with high precision. They work based on an electrical component called a strain gauge (also known as a load cell). The resistance of the strain gauge changes based upon the compression or change in shape of the component. A simple computer in the digital scale is preloaded at the factory with a table of values that allows it to calculate the weight of a load by the change in resistance. Many scales update about once a second, but better scales will update their readings much faster. This means, if you're pouring sugar into a bowl, the scale will provide almost instantaneous feedback so you don't pour too much. Most digital scales also have a tare function that allows the user to subtract the weight of the container from the measurement.


 
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