Several months ago, I started buying hazelnut flour from a bulk foods store. The recipe I use calls for one cup. When I first started using it, I weighed this out several times and it was always roughly 4 oz. so for months, this is what I've been using. I buy about 2 - 3 pounds at a time and every batch has been the same. With the most recent batch, it looked like the others. Felt like the others. Then I mindlessly weighed out 4 oz. into the KitchenAid bowl. When I looked at the bottom, there was A LOT of flour. I weighed it out again, and it was the same amount. Then I measured with a cup and there was 1-3/4 cup in there! Can anyone offer some insight as to why this happened?