Start with this: you're looking for a vibrant, slightly electric green—like fresh spring grass, not forest green. That brightness comes from chlorophyll, which builds up when tea plants are shaded before harvest. It's a good sign of proper cultivation.

But here's the trap: some cheaper matcha gets a boost with artificial coloring. That's rare, but it happens. So don't buy solely on looks. Check the label for 'ceremonial grade' (a loose term) and, more importantly, the harvest date. If it's more than six months old, the color will have faded, and so will the flavor.

A quick sniff test works wonders. Open the tin and take a whiff. Fresh matcha smells like fresh grass or seaweed. If it smells musty, old, or like hay, put it back.