Top and tail the beans and wash well
Bring a large pot of salted water to the boil (I recommend about 3 tbsp. of salt for every litre of water)
Have a bowl of ice water beside the stove
If you are cooking a large batch of beans do it in two or three steps ~ you should not blanch more than about two handfuls of beans at a time
Plunge the beans into the boiling water as soon as the water returns to the boil cook the beans for one minute and remove to the ice water
Cool thoroughly and remove the beans from the ice water
Place the beans in freezer bags and place as flat as possible on a tray
Label with the date and freeze for up to three months