What did I do wrong? Potatoes sprouting in storage

Well, the first thing we did wrong was buy a 10 pound bag of commercially-produced potatoes

But after that, I was all excited to find a place to store them in the cool of the coolest room in the basement, layered in a wicker basket, with newspaper in between layers. (Which is what I saw most recommended on random websites)

Previously storing potatoes upstairs in the kitchen cupboard was very clearly not viable for more then about three weeks before they starting going soft/sprouting. I believed the reason was it was too warm, and maybe not enough circulation.

So about six weeks ago I took most of this 10 pound bag and put them in a basket and put them in the basement. It is about 11 degrees Celcius in there, all the time. Is this still too warm? It's very dark in there.

It's the coolest place I've got (that's not the fridge, which I've read is too cold, and which is not outside, which is currently freezing.)

I've been bringing up a handful of potatoes once a week, for the week, last week I noticed they were getting a bit soft, and this week when I went to get them, I discovered that having finished the first "layer," the next layer of potatoes under the newspaper was all sprouty.

Much dissapoint, storing potatoes down in the basement seems to have only bought me about a week more of non-sprouty. And now I have all these sprouting potatoes that I'm probably going to have to throw out. I don't really have room for planting them, and while I've read that I should be able to store them outside in a dirt mound, I'm in town, there are cats and deer roaming through the yard pretty much nightly, and I'm just not convinced that would work or be pleasing to the neighbours.

Back when I lived in an old house in a city where January temperatures would regularly go below -35Celcius at night, the problem wasn't that potato storage was too warm, but too cold. We would discover frozen potato lumps in the kitchen cupboard once or twice a winter. It's sort of nice to have the opposite problem.

The best temperature is probably a bit lower.
Most people say somewhere between 35f to 40f is ideal. I've found that to be true. 11c (~52f ) might be a bit too warm, you should probably be able to store them for a month or two at that temp, although some varieties will store longer.

Storage temperature is not the only consideration, dark is also important. Also, modern potato varieties have been bred for very different characteristics than heirloom storage varieties. So far, the best storing "modern" cultivar that I've been able to find is Kennebec. I've also had good luck storing a few of the purple varieties. Friends have also reported good success with some red varieties.

Many vegetables have "fresh eating" and "storage" varieties, onions and squash are two that most people know. Potatoes don't seem to have many varieties advertised as "storage" but there are definitely large differences in store-ability. It helps to select a known good storage variety, although other varieties can store well, you're likely to have better luck with a variety that is known to store for longer periods.
You may want to experiment with clamping, if your outside temperature is cold enough. Although there are additional issues, such as wild life and weather, clamping is a time tested way to store root crops. I'm sure you could come up with a viable "micro-clamp" given enough ingenuity.

Good luck!

Vera, Could you give a clearer time-line for this observation? When did you buy this bag of potatoes and what were their origin (local? organic?...). You mentioned placing them in the root cellar about 6 weeks ago....how long were they at the warmer temperature upstairs? Our (home grown) reds and russets do pretty well in our cold root cellar and won't start sprouting for several more weeks. However, our Yukon Gold's are beginning to sprout already. My usual approach is to use the golds first for most dishes, then work more on the russets and finally the reds, the latter of which have the best storage for us. Seems the reds make better potato salad in late spring anyway, probably due to sugaring up.

Seems the reds make better potato salad in late spring anyway, probably due to sugaring up

If you ask me, the reds make the best potato salad any time of the year.
Reds are a great boiling potato. Salt, pepper, butter and chives, yumm, yumm.

Vera Stewart:

Congratulations on storing potatoes! I believe that you didn't do anything wrong... My potatoes have had sprouts for months. I store them at about 20 C. I'm still eating them. Potatoes that are stored for a long time get soft and grow sprouts. To me that is just a normal part of storing potatoes. Before cooking, I knock the sprouts off. If the skins have become too wrinkly/dry for the tastes of my family, then I peel them before cooking. They get soft during cooking, so I don't know how anyone would be able to tell the difference...

If it were me, I'd skip the newspapers. Seems to me like higher humidity leads to quicker sprouting, and skipping the newspaper I think would result in lower humidity. I grow potatoes in bulk though, so it would be hard to come up with that much newspaper. The general attitude around here, is that potatoes store better if they are not washed before storage.

Joseph Lofthouse wrote:If it were me, I'd skip the newspapers. Seems to me like higher humidity leads to quicker sprouting, and skipping the newspaper I think would result in lower humidity. I grow potatoes in bulk though, so it would be hard to come up with that much newspaper. The general attitude around here, is that potatoes store better if they are not washed before storage.

Seconding this. Whether the washing tends to remove something the potato has in it that decelerates the sprouting process or it's just an accumulation of moisture, washed potatoes don't last as long as those that came straight out of the ground and went straight into storage.

One option that might work is a sand box/barrel. Get extremely course sand and a box or barrel of some kind. Make sure there are holes in the bottom of your container and get it elevated off the ground. Layer some fabric on the very bottom to keep that sand in, then layer sand > Potatoes > sand > Potatoes all the way up to the top. Not a huge deal if a couple of potatoes are touching, but keeping them isolated help prevent any rot that might occur in one from spreading to another.

Re: Washed potatoes.....and eggs.

Will also attest to this and add eggs to the phenomenon. Beneficial bacteria are part of the 'coating' that you don't want to remove when putting something into storage. The bacteria can help retard infection by storage rot fungi and other pathogenic bacteria. So potatoes and pretty much all cellar-stored items are best left unwashed until needing to use them. But just to note that this fact seems to apply to storage rot.....not sure to what end this phenomenon affects sprouting. Eggs seem to be the same way. We keep eggs on the kitchen countertop for weeks,.....overflow of eggs go into the fridge. But only if the eggs are unwashed do we do this.....once washed, they are used within a few days or else we can count on many of them, if not most, going bad. Again, probably something to do with either biotic or abiotic natural protective coatings. If I recall correctly, most non-organic, commercially produced potatoes are treated with sprout inhibitor, but I wouldn't have a clue as to what the chemistry is. Unfortunately, commercial spuds are one of the more chemically-intensive field crops produced in the U.S., so if you eat a lot of them, not a bad idea to grow as much as possible with the knowledge of what you are applying to them....or buy organic if you can.

Joseph Lofthouse wrote:Vera Stewart:
The general attitude around here, is that potatoes store better if they are not washed before storage.

I agree with this, from personal experience. I don't wash my potatoes. Also storing potatoes in sand does work quite well, but I don't do it anymore, due to space constraints.

Wow, thanks everyone.

I'm having computer issues (I started a reply to this earlier today but then I got a white screen of death, now I can see what I'm doing but the screen is flickering, so...I'm just trying to be fast!) I don't want anyone to think I'm ignoring their potato-storage advice if I forget to mention it right now.

It did not occur to me that one of the issues could be the variety of potato I've purchased. I guess my general vague thought was that if the commercial potato growers/sellers can store this variety over the winter, without obvious sprouting, then I should be able to too.
But they're experts with proper infrastructure and temperature and humidity control, and I'm not.

I don't know what the proper name for these potatoes are. I still have the bag they came in, but it is non-informative. All it tells me is that they came from a farm about 170 miles away. They are relatively small and white. I only had them for about five days at regular room temperature before taking them downstairs, but no idea how long they sat in the store.

They were probably washed by the commercial packer, they seem pretty clean, although there are some specks of dirt. I don't wash them myself until right before I want to use them.

I went down to the basement electrical/paint can room root cellar and moved the basket of potatoes closer to the outside wall this morning, perhaps their average temperature will drop a further degree or two now, however, I ridiculously dropped the thermometer I was using behind a huge stack o' stuff that I'm not able to move, so I don't really have any way of knowing. It is really dark in the room when the light it off, and the light is only on when I'm in there looking at sprouting potatoes.
I have removed the newspaper.

I'm starting to look forward to finish eating this batch now, so that I can start storing a new batch in a more scientifically observed way! I could divide up the next bunch into a couple of experiment groups...and maybe I can buy some organic, some non-organic...

But first, I have to finish what I've got! I believe there's still about 5-6 pounds left, but I've put a bundle into a stew this afternoon to help the cause!

Potatoes can get pretty soft and shrivelly and still be edible if they aren't rotten or green! So they may be able to limp along for another week or two, if kept in the dark.

Vera, I agree with the others here. Go ahead and eat your sprouted potatoes. Of course , don't eat them if they are rotten (dark colored and smell bad) or green (exposed to light, potatoes turn green, all green parts of the potato plant produce the toxic alkaloid solanine)