inside of baked russet potatoes has big black streaks

Asked February 10, 2018, 6:55 PM EST

I bought a big bag of very large russet potatoes. I baked five of them and when I cut them open there were large streaks of black stuff through all of them (see photo). A week prior to baking these, I used some other potatoes from this same bag to make a casserole using raw potato slices; after peeling and slicing the potatoes there was no evidence of this. These baked potatoes were only a week older than the potatoes I sliced which were fine. I have never seen this before in a potato. What is it?

Summit County Colorado

1 Response

I suspect this is blackheart of potato and this would have been something that most likely occurred in the field or storage before the potatoes were sold. This is a physiological problem, not a disease. This publication from North Dakota State provides more information:
Let me know if you have any other questions.