Mange-tout - going brown on cooking

[Kitbloo]

Freshly picked, steamed/boiled/micro/whatever, half the batch goes brown and the other half are fine. Anyone got any ideas? Have not had this problem before, just this year.

[Flummery]

Sorry - I can't imagine what's causing it. Have you tried opening any of the pods just in case they have 'visitors'?

[Florence Fennel]

Well that's a strange one, what happens if you blanch and freeze?

[rustylady]

Are they all the same variety?