How does humidity affect the volume of dry ingredients like flour or salt, and what can you do to ensure accurate measurements on a very humid or very dry day?

Question

Find out how humidity can secretly sabotage your baking. Learn what you can do to ensure your measurements are accurate, even on a very humid day.

Answer 1

Humidity affects the volume of dry ingredients because they absorb moisture from the air, causing them to compact and weigh more for the same volume. To ensure accurate measurements, weigh your ingredients instead of measuring by volume, or fluff the ingredient before measuring on humid days.

Detailed Explanation:

Dry ingredients like flour, sugar, and salt are hygroscopic, meaning they readily absorb moisture from the surrounding air. On humid days, these ingredients will absorb more moisture, increasing their weight for a given volume. This means that a cup of flour on a humid day will contain more flour (by weight) than a cup of flour on a dry day. Conversely, on very dry days, dry ingredients may lose some moisture, resulting in a lighter weight for the same volume. This can lead to inconsistencies in your recipes, especially in baking where precise measurements are crucial. The impact is more pronounced with finely ground ingredients like flour compared to coarser ingredients like granulated sugar or salt. The absorbed moisture causes the particles to clump together, affecting how the ingredient packs into a measuring cup.

Pro Tip:

The most accurate way to measure dry ingredients, regardless of humidity, is to use a kitchen scale and measure by weight. This eliminates the variability caused by moisture absorption. If you must measure by volume, aerate the ingredient by fluffing it with a spoon or whisk before measuring, especially on humid days, to loosen any clumps and ensure a more consistent measurement.