How can I know whether a potato is too old?
I have many kilograms of potatoes that are turning bad, I don't want to throw them away. The term "turning bad" means that the best-before days on the products vary between 1-4 weeks i.e. they are old from 1 week to 4 weeks. Some of them taste bitter, some of them taste good but some black while some sprouting and other shape-changes. I am not looking for recipe recommendations, rather how to manage this problem. How can I know whether a potato is too old to be edible? If I can understand right, some sort of acid is formulated in some potatoes. Hence, I think I cannot cook the same products with them as with non-acidic potatoes. How should I manage acidic/non-acidic potatoes differently? Can I add some base to neutralize bad potatoes so they would become more edible?
Related Question but not the same
As of making good fried potatoes: boil once (in oil, obviously) for longer time (something like 8 minutes or so), take away, wait few minutes and then boil again for minute or two. That way those are more crispy.
@Olli: wow that is the way to do it, now I understand why Mc.* has such design. Thank you.
@hhh: on the other hand, Mc Donalds is not using raw potatoes, those are pre-processed first (before delivery to restaurant).
@Olli: do you know whether they are preprocessed with salt, vinegar, heated-slightly-with-water or how are they preprocessed?
If they have turned green-ish they may pose a health risk due to toxins, especially to young children and pregnant women.
@hhh, although this question already has a few answers I voted to close as off-topic because of the current definition of the FAQ (*every answer is equally valid: “What’s your favorite ______?”*). Please feel free to participate in the discussion about whether we should allow these types of "culinary use" questions on meta.
@stephennmcdonald: are you sure? Read the accepted answer, yes this question does have an objective answer by an expert. Sorry but the discussion is unrelated and blatantly dangerous to end aspiring open discussion. I stand on this question because I feel it is very important, for a number of reasons not just due to budget. Look I did not even think about toxic potatoes or getting ill, clearly good to have this kind of expert site!
Yes, unfortunately I am sure. *ANY* answer to this question is equally valid. I could say "french fries, home fries, baked potatoes, mashed potatoes, twice baked potatoes" and all 5 answers would answer the question. While I don't disagree that this might be a question with answers that are helpful to others, there is no *single expert answer* that can be given, and as it stands right now does not meet the requirements set forth by the community and the FAQ *for this site*. As I mentioned, if you feel this policy is bad, please participate in meta.
Please don't feel singled out, there are other recent questions which have also been closed for the same reason. See: What can I do with bananas? and What can I do with buttermilk? and What to do with leftover rice - these kinds of broad questions are closed on Seasoned Advice. The comments on the "leftover rice" question should give some more insight, and please participate in the meta discussion. Thanks!
@stephennmcdonald: yes you are right, the question attracts too much seasonal answers. There are however similar questions like  and  that have similar intrinsic goal to manage poor ingredients. Perhaps, this question should be specified to attract more advanced answers, instead of closed.  http://cooking.stackexchange.com/questions/8982/uses-for-old-bread-dough  http://cooking.stackexchange.com/questions/106/sniffing-out-a-rotten-egg-from-the-dozen
I agree that the first question should be closed (about old bread dough) as it is just "how can I use...?". I believe it was asked when the site was younger and this specific rule was not as well defined (I voted to close now that I it has been brought to my attention). The second, however, is about food-safety and asks specifically about that issue, but not uses for the eggs themselves. Therefore I believe the second question is valid.
As for your question with your new edits I think this is a great question and have up-voted it. It seems that I am not able to reverse my close vote unfortunately, but I believe it will stay open with these new edits anyway. If it is closed for some reason I will immediately vote to re-open!
@stephennmcdonald: thank you for your comments, really appreciate them.
It likely depends on what 'turning bad' means ...
If you have a couple in the bag starting to sprout, but the rest haven't, you can roast or bake the ones that haven't sprouted, let them cool, then store then in the fridge so you can pull them out to use them in something later in the week. (eg. home fries, patatas bravas or a hash).
For those that have started to sprout, but are still firm, you can cut away the sprouted bits (this time of year, you might even be able to plant them), peel them, and then boil them and turn 'em into mashed potatoes (which you can then vary for the next couple of days ... you can mash 'em with other stuff to make a sort of potato salad; you can add cooked greens to make colcannon or bubble and squeek; you can use as a topping for a cottage pie (the technically correct term for shepherds pie when you're not using mutton or lamb)
Some of these freeze well ... I've made up cottage pies and frozen 'em in oven-proof containers; you could likely do the same with just mashed potatoes -- I see 'em for sale in the grocery store all the time.
If you're looking for something to cook that just uses a lot of potatoes (in a non-whole state, in case you need to cut away parts) ... potato salad, potato bread, potato curry, latkes, potato soup, tortilla de patatas ... the list goes on.
... and if they're soft and squishy, or oozing liquid ... pitch them. They're rotting, and not worth getting sick over.
everything of them. Sprouting, oozing liquid, tasting bitter, some delicious and in good shape. I tried sugar and oil to fry potatoes, not good idea. Failure. I tried potato chips with salt in the hot container and noticed that it is very easy to get over-dosage. Failure. But potato chips work even with very poor potatoes, success. Now the challenge is to get a bit healthy alternatives. I have tried hash-brows (tastes good), still many kilograms left.
@hhh : your healthiest options are just to not fry them -- bake 'em (but not when you have spoiled ones in the batch), or maybe roast with other vegetables; you can also get vegetables in the colcannon, bubble and squeek or even a potato curry. I'd also try to sort through the potatoes to make sure to get the spoiled ones out of whatever you're storing them in ... and I'd be hesitant to use the ones at the bottom that might've been oozed on.
Good advice- I'd like to add- Don't freeze raw potatoes. Even in a casserole, etc. They turn gray and rubbery and altogether disgusting.
@Sobachatina: one of the biggest innovation in the last century was to find out how to freeze stuff quickly, it paved the road for frozen vegetables and eventually for modern fridge. Suppose I very quickly freeze potatoes, do they become gray and grubbery? I doubt that knowing the last detail but is there any consumer-product by which I could freeze potatoes very quickly which would extend their usage?
@hhh- My deep freeze gets very cold and if I lay fruit/berries out in one layer in a metal pan I can freeze them solid with minimal damage. I have never tried this with diced potatoes because they are always already incorporated into a casserole and so freeze too slowly. I suppose I could try prefreezing diced potatoes before building the casserole but it's a little easier to simply parboil them instead.