After-cooking darkening is caused by the oxidation of the ferri-chlorogenic acid in the boiled or fried potatoes. The severity of the darkening is dependent on the ratio of chlorogenic acid to citric acid concentrations in the potato tubers. Higher ratio normally results in darker tubers.
This process, which is called oxidation, happens because potatoes are a naturally starchy vegetable. And when exposed to oxygen, starches turn gray, brown, or even black. An oxidized potato is completely safe to eat. The process doesn't affect the flavor or texture of the vegetable.
After you remove potatoes from the cooking water, ferri-chlorogenic acid slowly mixes with oxygen, creating a color that can range from gray to black to purple to bluish. The color change is gradual.
“After cooking darkening” occurs in some potatoes and is the result of an imbalance of naturally occurring acids. Cholorgenic acid combines with the iron in the potato to produce the grey or dark appearance. Adding lemon juice during cooking prevents this reaction and eliminates the problem.
Check for soft spots, dark spots, sprouts, or green color. If the potato has little sprouts remove them, then prep potato for your dish. If there is a little green cut that off. If the potato has long spouts, is soft, wrinkled, or has lots of dark spots get rid of it.
If you boil potatoes for too long, they'll lose their structure and absorb too much water. That means that they'll become mushy, won't have the correct texture, and won't hold their shape.
The potatoes are done when they are tender all the way through. You can test this by poking the potato with a fork, paring knife, or skewer. If the utensil slides easily all the way to the center, the potatoes are done.
Test Kitchen Tip: You can boil potatoes ahead of time for use later as long as you cover and refrigerate them. They'll last for up to three days in the fridge.
Lenticels swell when tubers are exposed to highly moist soil or standing water for several days. When the bacteria enter the tuber, the cut, abrasion, or lenticel begins to discolor, decay, and even liquefy. The discoloration is creamy to tan and often outlined by a brown to black margin (Figure 2).
Small, bumpy, irregular black lesions that look like dark soil on potato tuber skin are the classic sign of this fungal disease. Caused by the fungus rhizoctonia, black scurf generally occurs near the end of the growing season. Black scurf lesions do not wash off, but can be scraped off with a fingernail.
Do cooked potatoes go brown? No. Once the starch is cooked, the potato won't go brown even if it is exposed to air for a while. If you have lots of potatoes that need to be used up, the best option is to peel and cube them, then cook them and freeze them in portions.
How long can peeled and cut potatoes sit in water before cooking, before they begin taking on too much water? A: We usually recommend no more than 24 hours. You can keep the potatoes from absorbing the water by making sure the water is not salted, and is chilled (you can even add ice to the water).
A pinch of a crushed vitamin C tablet in a little water works just fine even after the potatoes have already turned gray. The acid magically whitens them again by changing the pH, which is a measure of acidity. True to its name, ascorbic acid is acidic.
When slicing the potatoes place into water with a little acidity to keep them from turning gray. A small amount of white wine vinegar of lemon will do the trick. Then drain and place the potatoes in foil along with your spices and some olive oil or vegetable oil. Wrap up tight and refrigerate, then grill.
Bring the water to a boil. Reduce heat to medium low. Cover the pot with a lid and let simmer until fork-tender, about 10-15 minutes for small and/or cubed potatoes or 20-25 minutes for large potatoes. Drain and cool.
For most potato dishes it's important to add the potatoes to cold water and allow the water to come to a boil with the potatoes in the water. The potato starch can react as soon as it comes in contact with hot water, which will promote uneven cooking and mealy potatoes.
It's important to drain the potatoes immediately after cooking. Don't leave them to sit in the liquid while you finish preparing the rest of the meal. Potatoes retain their heat quite well, so putting them back in the pot after draining and putting a lid on them will keep them warm until you're ready to serve.
Visual signs: The potato skin will start to wrinkle when over cooked. The potato, when wrapped in foil or placed on the bottom of a pan will have a dark brown spot on the bottom, a sure sign of over cooking. Foil traps the moisture in the potato causing the skin to be wet and the inside flavorless or gummy.
Health experts have warned that overcooking foods such as toast, roast potatoes, chips and vegetables can lead to cancer. The Food Standards Agency says that starchy foods cooked at high temperatures for too long form acrylamide - a compound thought to be carcinogenic.
After you've cooked potatoes, you can store them in the fridge for up to three days. You can also freeze cooked potatoes. Boil them for at least five minutes before freezing. They will last for up to a year.
The long and short of it is that—yes! —sprouted potatoes are usually safe to eat. But you are going to want to trim those tiny growths before you cook the spuds. Keep reading to find out how to safely cook sprouted potatoes.
The short answer is yes. Potatoes that have sprouted are still OK to eat, but only once you've removed the sprouts. Here's a guide on how to remove them, how to properly store potatoes and when it's not alright to eat them.
Lack of pantry space or hot or humid conditions are all reasons you might want to store your potatoes in the refrigerator. If you do choose to refrigerate your potatoes for whatever reason, the potatoes will last for three to four weeks, but as mentioned, they may develop a sweeter taste when cooked.