These ones. I recommend this company in general, I’ve used them for storing oats and lentils etc in the past too, their containers are really sturdy. There’s lots of different sizes but I’ve found 4l is good for the powder. You could probably get away with 3.5L if you see another container you like, but I like having the bit of extra room at the top because it makes it easier! The h&s just barely fits into a 1.5L container.