Can I refreeze shortcrust pastry?
Absolutely, why not. If you defrosted it in the refrigerator then there is no reason why you couldn’t refreeze it. The real issue is why would you want to. I assume you rolled it all out and had some left over. In rolling it out, you worked the gluten in the flour and if you do it again with the leftover pastry, the dough will cook out to be tough and undesirable. Defrost in the refrigerator, cut what you need and refreeze the rest. Take note of how much you used and maybe in the future you can portion the pastry before you freeze it.
