Does the weather affect baking?

There is a lot of folklore here, and some of it is real. Sugar is hygroscopic, so anything that is essentially dried sugar — meringue, macaron shells, royal icing, honeycomb, fondant — genuinely does struggle in damp air and can stay tacky for days. Flour also takes up moisture from the air, so a bag stored in a humid kitchen carries slightly more water than the recipe assumes. What is not real is the idea that ordinary cakes and biscuits fail in the rain; those are far more sensitive to your oven than to the weather.

Step by step

1. Separate the bakes that genuinely care.Meringue, pavlova, macarons, royal icing, fondant, honeycomb, toffee and anything else that is mostly dried sugar. These are the cases where humidity is a real, practical obstacle rather than a superstition.
2. In damp weather, extend drying and resting times.Macaron shells that skin in twenty minutes on a dry day may need well over an hour. Royal icing that dries overnight may need a day and a half. Do not force the timetable — bake to the state, not the clock.
3. Hold back some liquid in doughs and batters.In persistently damp conditions, keep back five per cent of the water and add it only if the dough needs it. Flour that has absorbed atmospheric moisture needs less.
4. In hot weather, cool the yeast down.Use fridge-cold water and cut the yeast by a quarter. A dough that takes ninety minutes in a 19°C kitchen can over-prove in fifty at 27°C — this is the commonest summer baking failure.
5. Chill fat harder in the heat.Pastry, shortbread, lamination and biscuit doughs all depend on solid fat. Chill the bowl, the flour and the worktop, and work in short bursts with fridge breaks.
6. Store finished bakes against the weather.Meringues and dried sugar work go into an airtight container the moment they are cold, ideally with a silica sachet. Left out in a humid room they go sticky within hours.
7. Do not blame the weather for oven problems.A cake that sinks, a loaf that stays pale, a biscuit that burns — these are almost always temperature, timing or measurement. Check the oven before you check the forecast.

Tips

• A silica gel sachet in the meringue tin is cheap and works. Save the ones that come in packaging.
• A dehumidifier in the kitchen makes sugar work possible on days it otherwise is not, and it is the reason professional kitchens have controlled environments.
• Store flour sealed rather than in the paper bag. It is both a pest measure and a moisture measure. See `store-flour-and-dry-goods`.
• Altitude genuinely changes baking — lower boiling point, faster rise — but nowhere in the UK is high enough for it to matter. Ignore altitude adjustments in imported recipes.

Common mistakes

• Blaming the weather for a bake that fails all year round — It is a convenient explanation that stops you checking the oven, the scales and the raising agent, which are far more likely.
• Making meringue on a wet day and forcing the timing — The shells simply will not dry. Either accept a much longer drying time or make something else.

If it doesn't work