Potato 'Concretions' ?

[rotuts]

Im having a SV 'Roast Beef' dinner with mashed potatoes and baby peas (yes those canned items rinsed etc)

I currently get my Potatoes from the local farmers market

tonight's are red skinned Bliss potats.

unlike the MegaloMart Bliss these need to be scrubbed. no big deal

but they have denser 'dirt' concretions on them that take a stiff brush to remove.

i soak them in cold water for 10 mins then go at it.

what are these little Nubbins? dirt with a little potato 'jus' ?

just curious. crafty little devils they are!~

[heidih]

Can you post an image of them?

[Country]

The "...denser 'dirt' concretions on them that take a stiff brush to remove" may well be potato scab, which needs to be removed with a knife or peeler. But, as Heidi suggested, a photo would help.

[Panaderia Canadiense]

I know exactly what rotuts is seeing - they're denser accretions of soil on the potato, not scales. Alls I can guess is that there were root hairs there before the spuds were pulled, and the teensy bit of potato sap that bleeds when those are removed cements the dirt on there. I usually scrape them off with a knife or a thumbnail.

[Country]

Root hairs? I've been growing potatoes for quite a while and I've never seen root hairs on potatoes. Carrots, yes. Potatoes, no. At least in Maine.

[rotuts]

I ate them all ! didnt think of a pic.

if I can find some more at the market sat. Ill try for a pic.

stay tuned!

i went a looked again and found three I didnt cook last PM they were a little larger

they are red and have no concretions. their skin is not as thin as the smaller ones so they might not be bliss, but interesting no concretions on these

they come from an organic farm so were probably not treated differently.

more info sat.

Edited November 7, 2011 by rotuts (log)

[Country]

In the meantime, try checking out the pics on this Google search for potato scab in case that resembles what you were looking at. Some of them have lots of scab, but the left potato in the group of three all the way to the left is closest to what I usually see around here. Organic potatoes are most likely to have scab because we don't use all the chemicals that big commercial (industrial) farms use.

[rotuts]

the scab pictures are quite interesting.

this is not scab: it does not penetrate the skin. comes off with a stiff bush, not a soft one and the skin under the Nubbin seems undamages.

maybe ill go buy some more today

oddly interesting.

[AnythingButPlainChocolate]

I'm guessing, rather than a corky lump than penetrates the skin, it's like a hard dark brown/black flake that can be picked off or brushed off?

If so it's a fungus known as potato rhizoctonia, or black scurf. (Info can be found here.) It doesn't cause a problem to taste, but it is quite common on home grown and potatoes sold unwashed.

Edited November 8, 2011 by heidih
Delete protected image (log)

[Panaderia Canadiense]

Root hairs? I've been growing potatoes for quite a while and I've never seen root hairs on potatoes. Carrots, yes. Potatoes, no. At least in Maine.

Depends. Maine soil is quite rich, so potatoes grown there wouldn't develop the hairs in their search for nutrition. Here in the Andes, the most marginal of soils is where the spuds are planted, and they do develop hairs. There are also roots that chain tubers together, and these also leave scars in the harvesting process, particularly if the farmer is digging by hand (as is the standard here).

This said, I've found they're a bigger problem on the Atahualpas and Criollos (red-skinned varieties) and almost absent on Oro Morado (purple skin, white flesh), Locro (yellow soup), and Chullo (yellow friers). I've also found accretions on some Mashua, Melloco, and Ullcu (native tubers).

Maybe it comes down to soil type and how the potatoes are handled during and after harvest?

[rotuts]

yep.

its black scurf.

who knew?

comes off with a stiff brush and a little pre-soak.

not on the larger 'reds' which might be a different variety or from a different location.

Edited November 7, 2011 by rotuts (log)

[AnythingButPlainChocolate]

I grow them at home, and I find that certain types of potato are more susceptible than others to various diseases and fungal infections, of all the stuff potatoes seems to get hit with, it's one of the nicest and easiest to deal with.

Glad I could help.

[Country]

Root hairs? I've been growing potatoes for quite a while and I've never seen root hairs on potatoes. Carrots, yes. Potatoes, no. At least in Maine.

Depends. Maine soil is quite rich, so potatoes grown there wouldn't develop the hairs in their search for nutrition. Here in the Andes, the most marginal of soils is where the spuds are planted, and they do develop hairs. There are also roots that chain tubers together, and these also leave scars in the harvesting process, particularly if the farmer is digging by hand (as is the standard here).

This said, I've found they're a bigger problem on the Atahualpas and Criollos (red-skinned varieties) and almost absent on Oro Morado (purple skin, white flesh), Locro (yellow soup), and Chullo (yellow friers). I've also found accretions on some Mashua, Melloco, and Ullcu (native tubers).

Maybe it comes down to soil type and how the potatoes are handled during and after harvest?

Thanks. I thought maybe things might be different down there, which is why I added that I was referring to Maine. Your region (South America) is the potatoes' home and I've heard, for years, of all the different varieties there. It must be truly wonderful! In Maine, we're much more limited in choice.

We don't get root hairs, and maybe we have better soil, but we definitely don't have the wide varieties and choices you have. And I'll bet many of your potatoes taste better than what we grow here.

So far as "scab" and "scurf", maybe there's no difference to us home-growers. It's all scab to us.

But, I think it's mainly due to soil fertility and make-up. Imbalances mostly.

[Panaderia Canadiense]

In season, there are up to 150 varieties at market, of which 15-20 are considered "standards" - and then there are the non-potato traditional tubers as well (Ullcu, Melloco, Mashua, Camote). We're out of season at the moment (which is why I didn't show you potatoes in the blog last week), which means that Atahualpa and Oro Morado are the most common - and that's a geographical variance. If I were in Ibarra at market, I'd see a lot more Corazon Azul (blue heart), which are among my favourite potatoes, but Oro Morado would be absent.