Gochugaru pantry staple - which form to stock?

Thank you!

I'm with Nancy on this. Buy the flakes, because you can always pulverize them to make powder. Since you won't use it that frequently, store it in an airtight baggie in the freezer. I put mine up in smaller bags that I can vacuum seal, because that helps it keep longer still. Mine usually lasts 6-8 months before flavor loss starts to be apparent. Watch the color, and when it fades to yellow-orange, it's time to replace it.

I would choose flakes, because they hold their flavor longer than ground spices.
And you can always crush them into powder (many ways) if a recipe calls for ground format.