Why do beets turn black? My first occurrence of this was in August of 2014, that’s when I wrote the following post. Since then, I’ve received feedback and comments from readers who have experienced black beets after preparing them in various ways – boiling, roasting, with or without aluminum, it doesn’t seem to matter. My initial conclusion in 2014 does not seem to hold true. It continues to be a mystery.
My latest theory is that maybe the blackening of beets is similar to blackening of boiled potatoes. I’ve got emails out to crop specialists – hope they may be able to help. Getty, Aug 2016
Here’s what I wrote in 2014:
I was so excited to harvest these red and gold beets from my garden. It’s the first year that I grew golden beets and I was excited to cook up my first batch. Look how gorgeous these guys are!
Normally, I boil my beets, peel ’em then dice ’em. But I wanted to treat these beauties special, so I looked up an Ina Garten recipe for roasted beets. It said to peel and dice the beets, so I did.
Ina did not say to put them on a sheet of aluminum foil. I did that on my own, because I was being lazy and read a million other recipes that recommended doing so.
When I pulled them out of the oven, I was disappointed. The beets looked dirty with a few black spots and an all over look of gray. The beautiful color was gone, I didn’t even take a picture because they were really not photo worthy. We ate some and they still tasted good, but they weren’t pretty or special. I put the leftovers in the fridge.
Here’s what those leftovers looked like the next morning – CAUTION these images may be upsetting to some readers!
The black dirty look had intensified. It looked horrid. Even the red beets turned black, it was just more difficult to see. What happened? The flavor wasn’t affected (yes, we tried them), just the color.
I scoured the internet looking for answers – was it just me, was it my beets, was it the recipe?? What?
Google came up with tons of results to my query, but it did not provide the straight forward answer I was looking for. There were lots of discussion threads about similar occurrences and quests for answers like mine – but no conclusive answers. At least it wasn’t just me or my beets.
People had lots of guesses: beet variety,oxidization, the sugar/starch in beets, too much manganese in the soil, a reaction to the aluminum foil, peeling them before roasting, the beets were picked too early, need to soak them in lemon juice, etc.
I didn’t find anything conclusive, so I thought about what I did differently this time than the gazillion other times I’ve cooked red beets and did not experience this issue. This was the only time I peeled the beets before cooking and I roasted them on aluminum foil.
Last night I harvested more golden and red beets, determined to do better. I made them the way I normally cook beets. I washed the soil off, cut off the greens and tossed the whole beets in a pot of water where I boiled them until they were fork tender (20-40 minutes depending on size). I took them out of the hot water, rinsed them in cold water, allowed them to cool, peeled and diced them. Here’s what they looked like:
Beautiful and photo worthy! Not a spot of black.
To extend the experiment, I put some boiled yellow and red beets on top of aluminum foil for 1 hour to see if they would turn color. Nothing happened. I also stored some in a container in the fridge overnight. The yellow beets were stained red where they touched the red beets, but other than that there were no color changes. No black.
I still don’t fully understand why the peeled roasted beets turned black, but I do know, I’m not going to peel beets and roast them on aluminum foil again! Boiling them with the skin on works best for me. If I were to roast beets again, which my friends next door do with beautiful results, I would definitely leave the skin on.
Now I can make Apple and Beet salad, one of my favorites from the Prairie Fruit Cookbook.
Have you ever had your beets turn black? Do you know the scientific explanation – please tell us!
Getty Stewart is an engaging speaker and writer providing tasty recipes, time-saving tips, and helpful kitchen ideas to make home cooking easy and enjoyable. She is a Professional Home Economist, author of Manitoba’s best-selling Prairie Fruit Cookbook, Founder of Fruit Share, mom and veggie gardener.