Cooking with little water

In cooking, water is lost in three ways: it is poured off, it evaporates, or it is used for rinsing. Tackling all three gets you by with a fraction of the usual amount. The biggest gain comes from choosing foods where nothing is poured off at all.

Grains such as oats, couscous, bulgur or rice cooked by the absorption method take up all the water. Couscous and bulgur often do not even need cooking, just pouring over hot water and leaving to stand. Instant mashed potato works similarly. Pasta can be cooked directly in the sauce, with only as much liquid as it absorbs.

A lid noticeably reduces evaporation and saves fuel at the same time, because less heat escapes with the steam. Turning the heat down after boiling or putting the pot into a hay box loses even less.

Measure instead of guessing. Package directions or a measuring jug show how much water a food needs. Better to use a little less at first and add more if needed than to have to pour some off at the end.

Whatever is left over gets reused. Pasta or vegetable cooking water can be the base for soup or sauce. The liquid from tinned vegetables can be cooked along with the dish if it suits – but it is often salty and therefore not suitable as drinking water.

Washing up can be economical too: wipe off leftovers with paper first, scrape or soak pots with a little water immediately before anything dries on, and wash in a bowl rather than under running water. Serving from the pot and marking a plate for each person saves even more washing-up.

For cooking, brushing teeth and washing dishes that touch food, use only safe or treated water. Rainwater or utility water is unsuitable for this unless it has been treated. If a boil-water notice is in force, follow the authority's advice exactly.

Drinking water is not cut back in favour of cooking. If water is so short that drinking would be at risk, choose foods that need little or no water – tins, bread, nuts – instead of cooking. Remember too that very salty food makes you thirsty and so increases water needs.

During a water supply failure or a boil-water notice, every litre that does not have to be bought, fetched or boiled counts. A menu of absorption dishes, stews and tins reduces the need considerably – and fuel consumption at the same time.

On trips with limited water the same applies. Oats, couscous or instant meals that soak in a bag or mug with hot water need no real washing-up. A pot with a lid, a spoon and some paper to wipe it out are often enough.

Health authorities such as the US CDC stress using only safe water for drinking, cooking and brushing teeth in an emergency. Ready.gov explicitly advises not to ration drinking water but to save on everything else.

The tips described here come from cooking practice and have not been scientifically measured; this entry therefore gives no fixed water quantities per dish. It is best to try them in everyday life – many of them save water, energy and washing-up even without an emergency.