Measuring cups lie and scales do not

The options around measuring ingredients are set out side by side below, with the conditions that genuinely favour one over the other.

Why volume varies

Flour scooped straight from the bag compacts and holds noticeably more than flour spooned in and levelled. That difference is large enough to move a cake from tender to dry, using the same recipe and the same technique. Brown sugar is worse, since recipes often specify packing it, which is an instruction with no defined force.

Anything that can settle, clump or aerate is unreliable by volume, which covers most dry baking ingredients.

Weight removes the whole problem

A hundred grams of flour is a hundred grams whether it was scooped, sieved or poured. Weighing directly into the bowl also removes the intermediate cups and spoons, which is less washing up rather than more.

The part that matters: a tare function means several ingredients can go into one bowl with the display reset between them. Digital scales are inexpensive, and there is no serious argument for a kitchen not having a set.

Cups are not standard internationally

The cup used in United States recipes, the metric cup used in Australia and other national conventions differ from each other. A recipe from another country in cups may therefore be wrong by a meaningful margin before you start. Tablespoons differ too, with the Australian tablespoon being larger than most others.

The part that matters: weights in grams are universal, which is why they are worth converting to once rather than guessing repeatedly.

Where volume is fine

Liquids are reasonably consistent by volume, since water does not compact. Small quantities of things where precision hardly matters, such as a spoon of oil in a pan, are fine estimated. Even here, salt is the notable exception, because different salts have very different densities for the same spoon.

For anything structural in baking, volume is a false economy dressed up as convenience.

Reading a recipe carefully

Whether an ingredient is weighed before or after preparation changes the quantity, so a hundred grams of nuts chopped is not the same as chopped nuts weighing a hundred grams. Sifted before or after measuring makes a similar difference with flour.

At the stove, good recipes are explicit about this, and vague ones are a warning sign about the rest of the instructions. When in doubt, the version that gives weights is usually the more carefully tested one.

Precision where it matters

Bread, cakes and pastry need accuracy because the ratios are structural. Stews, soups and stir fries tolerate wide variation and can be cooked entirely by eye. Knowing which category you are in is what stops precision becoming a chore in everyday cooking.

In practice, a second smaller scale reading in tenths of a gram is only worth it for yeast, salt and leavening in small batches.

Side by side

The takeaway

Weigh anything structural, estimate anything forgiving, and stop converting cups by guess.

Taste it before it leaves the pan. That is most of cooking.