How much drinking water should you keep at home?

The usual guidance is around two litres of drinking water per person per day. In UAE summer, for anyone spending time outdoors, three is more realistic.

For a family of four, that is roughly 8 to 12 litres a day, or 60 to 85 litres a week. A pack of six 1.5 litre bottles covers a day. A fortnight's supply for that family is around eight packs.

Buying two weeks at a time is usually the sweet spot. It is enough to get the bulk price and cut the number of deliveries, without needing a cupboard you do not have. Going much beyond a month rarely pays: you tie up space, and stored water does slowly change.

It does not spoil in the way food does. Sealed bottled water is safe well past the date on the label. What changes is taste. Two things cause it: plastic, which very slowly transfers flavour, especially when warm; and light, which allows algae to grow in bottles left where the sun reaches them.

So store it the same way you would store oil. Cool, dark, away from an exterior wall. Never in a car boot, and never on a balcony, however convenient. A sealed bottle that has spent a Dubai August in direct sun will taste of the bottle.

Rotate the stock. Newest at the back, oldest at the front, so nothing sits for a year while you drink around it.

One more thing worth knowing: keep a few litres genuinely spare, separate from what you drink day to day. Not for an emergency in the dramatic sense, but for the ordinary one where the building's water is off for an afternoon and nobody warned you.