I have a bumper crop of french beans, runners, and (earlier in the summer) peas. I know that we're supposed to blanche vegetables prior to freezing and my general purpose cookbooks tell me how long to give each vegetable.
I believe that blanching helps retain flavour, colour and vitamins. But I don't understand how or why. It seems counterintuitive that the best way to preserve the vegetable immediately prior to freezing, as close to its natural state as possible, is to apply heat via boiling water.
You would think that just picking the vegetable and bundling it into your freezer as fast as possible would be the best way to preserve colour, vitamins etc.