Keep it in a sealed glass container, and it should keep in the fridge for two weeks or more. (Don’t add sugar) The glass is air tight, and will keep it longer.

It will also keep longer if you put it in the fridge immediately after making it. The less time any food spends at room temperature, the better.

You can use a metal container, but some metals impart a taste on the tea. Some plastics (not all) have an oxygen barrier as well. The easiest way to tell which ones do is to re-use a retail container that had tea in it (Arizona Iced Tea has a one-gallon size). Note: Retail teas, when sealed, are easily storable for two-four weeks – read the “use by” dates.

Most commercial plastic food containers, like tupperware, also have oxygen-barrier properties that will also work.

Oh – and shake before use to assure consistent mix, otherwise your tea will get stronger with every pour.

A week at most…

I’d say five days tops.