Bottles, infusers and leakproof caps

A bottle is judged on its cap. Volume, colour and material come after: the cap decides whether it goes in the bag every morning or into the cupboard after three weeks. A cap that leaks in a bag once never travels again.

The second criterion is what goes inside. Borosilicate glass takes boiling water, so tea, but not the reverse thermal shock: ice cubes straight after a hot brew and it cracks. Tritan does not break but will not take a hot dishwasher cycle — the markings fade and the cap warps. These are not faults, they are fields of use, and knowing them prevents disappointment.

Third point: tea left in its bottle keeps brewing and turns bitter within an hour. A removable basket settles that in one movement, and it is the difference between a tea bottle and a bottle you put tea in.

See also our **Cut clean** and **Cook without watching** aisles.

One last thing, on volume: a litre you actually carry beats a litre and a half that stays on the desk. Weight and cap decide what leaves the house, not the number printed on the side.