Posted: 13/07/2013 at 17:24
I wouldn't blanch them for so long. As soon as they come back to the boil is long enough.
For large quantities: Put a washing-up bowl (or whatever you can fit in) in the freeezer with water in the bottom. Freeze the water. Blanch the veg and after draining pour onto the ice to which you have added some water - not too much.
For smaller quantities pour into ice cubes and water.
Blanched vegetables should be cooled completely in the same time they were blanched for.