[MHGinTN]

Two things:

If manufacturers would put peanut butter in straight side jars the last remnants wouldn't be so devilish to extract; but the shape is probably related to the plastic surviving the temps and pressures during canning.

Used peanut butter jars make good 'collection' jars for garbage at the sink, like veggie peels and used tea bags and K-cups, because you can tighten the lid and toss them in the trash when full of garbage and the garbage can doesn't stink for the period before being hauled out to the rubbish bin. I use quart yogurt containers this way too.

Oh yeah, and I nearly live off of peanut butter. I even stir a couple of tablespoons of it into my oatmeal.

[Daffynition]

Do you cook it in the jar?

http://whatisjennifereatingnow.blogspot.com/2011/01/overnight-oats-in-jar.html