Once a month, take stock of your matcha stash. Check the color and smell. If it's faded or smells musty, it's past its prime. Proper storage—an airtight tin in the fridge—can stretch freshness for a couple of months, but matcha is best used within 4–6 weeks of opening. So only buy what you'll realistically use in that window.

If you're mostly a weekend drinker, a small tin of ceremonial grade might last you longer than you think. But if you're baking regularly, a larger culinary pouch will save you money in the long run. Consider how much you consume in a month and adjust your purchase accordingly.