Why do runner beans not come back from freezing very well?

A common problem, I usually salt them.

Take a large Kilner jar (or similar) wash, rinse and dry.

String and slice beans

Place a thin layer of salt in the bottom, then a thick layer of beans followed by salt layer and so on until jar is crammed full, finish off with a final layer of salt. Close jar and store in a dark cupboard, invert it occasionally to make sure salt spreads throughout.

It takes more beans than you think.

To cook rinse and soak in plenty of water, changing frequently then cook as usual.

They'll never be the same as fresh but if you par boil the cut beans first in boiling water for about 1 minute and then plunge them into iced water or running water so that they cool down fast, they shouldn't be too bad though.

They may not have frozen very quickly. I just wash them and put them into a freezer bag. Choose the coldest part of your freezer. Usually at the bottom back.

I normally blanch mine and they are ok or they need to be frozen quickly

It may have happened if you hadn't blanched them

Chetak