If I use lentils as pie weights to blind bake a crust, can the lentils be cooked later, or are they toast?
They should be saved to be used as pie weights again. You could probably cook them but they would taste bad.
Or you could just invest in a jar of pie weights. They're not that expensive. And if you bake pie crusts frequently...
Pie weights aren't very much and you can use them for years and years. I have ceramic ones.
They will be dried out, not very palatable, if you try to cook them. My favorite pie weights are dried beans, which can be used over and over (mine are several years old) and exceedingly cheap.
They are definitely toast. Like @mainecook61, I just use dried beans as pie weights. I keep them in a jar, and I've used them for years. I think this year I will buy actual pie weights, but beans work great in a pinch.
They're toast. Could be used again as weights. I'm a prof baker-at home I use marbles. They're reuseable forever!