When do you need a kitchen scale?

A kitchen scale is useful not for being used at every meal but for showing where your eye goes wrong. The real question is not whether a scale is needed but how long it will be used.

Where does the eye go wrong?

The human eye is not equally wrong about everything. With things that are large in volume and light, leaf salad or popcorn for example, judging by eye usually works well. With dense, small-volume things, nuts, cheese or oil for example, the same eye is clearly wrong.

That error is not carelessness; it happens because the relation between volume and weight differs from item to item. And that is where the real function of a scale appears: not to measure everything, but to show once which items the eye is wrong about.

The size of the bowl adds to the error too. The same amount looks like little in a wide bowl and a lot in a small one. Once the scale has been used, you have also learned how much each bowl at home holds, and that bowl later turns into a measuring tool of its own.

How long do you have to use the scale?

A permanent habit of weighing becomes tiring for most people within a few weeks and gets dropped. The more workable route is to use the scale briefly and with a purpose: for one week only a few items are weighed, the result is kept in mind and the scale is put away.

What is left at the end of that short period is not a habit but a calibrated eye. Someone who has seen once on a scale how a handful of nuts looks in their own bowl acts consistently afterward without one.

The same calibration can be refreshed once or twice a year. When the bowls change, when you move house or when a new ingredient comes into the kitchen, the scale comes out again for a few days and is then put away again. This is far less tiring and lasts far longer than measuring all the time.

Which items does weighing really change things for?

The items it changes things for are the ones carrying a lot of energy in a small amount: oil, butter, nuts, cheese, chocolate and dried fruit. These are the items usually put in by eye in the kitchen, and the ones the eye is most wrong about.

Weighing items such as vegetables, soup and salad is usually an unnecessary burden. Spreading the scale to these items too is what makes the habit impossible to sustain and gets it dropped altogether in the end.

Another useful side of a scale appears in scaling recipes. Halving or doubling a recipe with cup and spoon measures builds up error; done by weight, it is calculated directly.

What if the scale turns into a means of control?

The function of a scale is to give information, not to pass judgment. An arrangement in which every bite is weighed and eating without weighing creates unease has stopped being measurement and has begun to make the relationship with food harder.

If the scale has turned into a source of anxiety, it should be put away for a while. If your relationship with food is strained, or if you cannot let go of the urge to measure, you should talk to a dietitian and, if needed, a doctor; this content does not replace a personal assessment.

What do you do without a scale?

A measure can be set up without a scale as well. A particular bowl, a particular spoon or a particular glass at home is chosen as a fixed measure and the same one is always used. That does not give the absolute amount, but it gives consistency from day to day.

In most cases consistency is more useful than absolute accuracy. Knowing whether one meal was larger or smaller than another is needed far more often than knowing an exact number in grams, and it needs no tool at all.

Always using the same measuring vessel also sets up a shared language between the people who share a kitchen. In a home where everyone uses the same bowl, arguments about portions drop by themselves, and recipes become something that can be passed on from vessel to vessel rather than from home to home.