My grandma's "no cold butter" rule sounded like a myth until I ruined 3 batches of biscuits in one weekend
I bake biscuits most Sundays and for years I took cold butter straight from the fridge and cut it into the flour, thinking cold meant flaky. Then my grandma watched me do it in her kitchen in Tulsa and told me the butter has to sit out about 20 minutes first, just until it gives a little when you poke it. I ignored her and made three batches that Saturday, and all of them came out flat and tough like hockey pucks. What I figured out is that rock hard butter shatters into dust instead of leaving little flat flakes, and those flakes are what make the layers. When the butter is slightly soft, it smears into thin sheets in the dough and steams apart in the oven. Now I set the butter on the counter when I preheat and it works every time. Does anybody else's family have a baking rule like this that sounds fake but turns out to be real?