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.
Add lemon juice or vinegar
Lowering the pH of the potato helps fight off oxidation. Just like you might use a squirt of lime juice to keep guacamole from browning, a bit of lemon juice or white vinegar in the bowl with the potatoes will ward off gray hues.
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-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.
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.
Larger pieces (about 2 inches across) may need longer, around 15 minutes. Medium whole potatoes should boil 20 minutes before they'll be tender. Even larger potatoes, such as those that are baking potato size, may need 25 to 30 minutes.
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.
A: Once cooked (whole or cut) potatoes can be stored in water (with or without vinegar) without becoming discolored or mushy. But, water storage isn't necessary. Refrigerate the boiled potatoes in a sealed container and use within a couple of days.
When I started to peel my potatoes, I noticed small grey or black spots. Some of the spots even looked like mold. These spots are called internal black spot and are essentially bruising that occurs from the potatoes lying against each other for an extended period of time.
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.
When potatoes are cut, especially into smaller flakes like your would for hash browns a lot of the starch begins to oxides and will cause the potatoes to turn gray. That starch is turning into sugar, mixing with the moisture in the potatoes which also causes it to become gummy.
Foil holds in moisture and steams the potatoes, resulting in a "boiled" taste and texture. Plus, without the use of foil, the skin will get extra crispy and flavorful.
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.
If you're here, you'll probably be glad to know that yes, you can peel and cut potatoes the day before you plan to serve them — and that it's super easy! All you have to do is submerge the bare potato pieces in water and refrigerate (more on that later).
Some people may prefer to peel the potatoes before boiling, but we would recommend you leave the skins on. This ensures that the nutrients and flavours are not lost during cooking and you get all those lovely vitamins too.
Potatoes soak up a lot of flavor, so salting the water prior to cooking is a good idea for the best taste. And you aren't limited to plain salted water for boiling your potatoes, either.
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.
Always start potatoes in cold water.
Dropping them into boiling water is a bad idea because the hot water will cook the outsides of the potatoes faster than the insides, leaving you with unevenly cooked taters. By the time they've fully cooked to the core, the outsides will be mushy and start to flake apart.
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.
Or, to put it another way, potatoes added to boiling water cook unevenly. If, on the other hand, you place potatoes in a pot of cold water, the water and potatoes heat up together, and the potatoes cook evenly inside and out.
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.
Can you bake potatoes without foil? Yes, there's no need to wrap your potatoes in foil while baking. You can just as easily bake potatoes on a baking tray lined with parchment paper without foil wrapped around them. However, we recommend brushing on some olive oil dressing to make the potato skin crispier and tastier.
"Yes, it's good to prick them," Smith told Food52. "It pokes holes in the skin, which allows steam to escape. Otherwise, they could explode—it doesn't happen all the time, but it happens every once in a while. The potato is full of water it's trying to turn to steam, or water vapor.
Wrapping potatoes in foil does not hasten baking. On the contrary, since the foil itself has to be heated before the potato begins to bake, cooking times increase slightly. Not only do you get better baked potatoes when you bake them unwrapped, you also save money.