Ask Dr. Potato

Top 5 Frequently Asked Questions

1. What is the Difference Between Idaho® Potatoes and Russets?

Russet potatoes are grown in many states, however, only potatoes grown in Idaho can be called Idaho® potatoes.  Idaho’s ideal growing conditions – the rich, volcanic soil, climate and irrigation – are what differentiate Idaho® potatoes from potatoes grown in other states.  

“Idaho® potato” and the “Grown in Idaho®” seal are federally registered Certification Marks that belong to the Idaho Potato Commission (IPC). These Marks ensure that consumers are purchasing potatoes that have been grown in the state of Idaho.   

The IPC works hard to protect these trademarks and ultimately the integrity of the ‘”Idaho® potato” brand, which is recognized around the world as a premium potato. In fact, recently a trial was held in the U. S. District Court for the Southern District of New York where a jury  concluded, and a Judge affirmed, that “Idaho” was not generic for any russet potato.                   

While the russet is the most well-known potato grown in Idaho, more than 25 other potato varieties are grown in Idaho including:  Yukon Golds, Reds and Fingerlings. 

2. How do I know I'm buying Idaho potatoes?

To be sure you're getting genuine, top-quality Idaho Potatoes, look for the "Grown In Idaho" seal, which features a silhouette of the state of Idaho, and for the registered certification mark, "Idaho Potatoes."

Genuine Idaho potatoes have a rounded, somewhat elongated shape, few and shallow eyes, net-textured skin and a deep brown color. Look for clean, smooth, firm-textured potatoes that have no cuts, bruises or discoloration.

Don't buy potatoes that are soft or have excessive cuts, cracks, bruises or discoloration and decay. If your potatoes have any green spots, pare them off before cooking because they could taste bitter.

3. I purchased Idaho potatoes and they looked good but it turns out they were rotten on the inside, why did this happen?

When Idaho potatoes are shipped from our state there is a quality control inspection performed on them.  This is just one of the reasons Idaho has such a good reputation for growing the highest quality potatoes in the world.  When produce is received by the intended retailer it is inspected by the US Department of Agriculture, if there is any question about the quality.  The Idaho shipper has no control after their potatoes have been received by the retailer.  

It is possible that your purchase was on the shelf longer than the retailer intended.  In most circumstances when a consumer purchases a produce item from a retail store which they are dissatisfied with, you only need to return the unused portion and the sales receipt to the retailer and they will replace or refund your money.

4. Why are my potatoes turning green?

The greenish color sometimes seen on potato skins occurs when the potatoes have been exposed to natural, artificial, or fluorescent lights.  This can also occur if when a potato is growing a crack in the soil exposes the potato to sunlight.  This is mostly discovered before being sold.

Greening happens a lot more than it used to because supermarkets are often open for longer hours so their displays receive more direct light.  However, it can also happen at home if you store your potatoes out in the open where they are exposed to light.

The green color on the potato is chlorophyll developing in the skin and along with this change, increased quantities solanin is also formed.  Solanin is part of the flavoring complex that gives the potato its taste.  This is concentrated close to the potatoes surface and is easily removed when peeled.  Only if the potato has prolonged exposure to light will the bitter taste and color penetrate deeper into the potato.  

We recommend that you don’t eat the green part of the potato because of its bitter taste.  Just peel away the green sections before preparing the potatoes and serving to your guests.

5. Can I cook Idaho potatoes in the microwave?

With the invention of the microwave, cooking potatoes has become much faster and more convenient. Many claim that the microwave actually bakes a more nutritious potato than a conventional oven, because the potato is exposed to nutrient-draining heat for a shorter period of time. 

Potatoes should be scrubbed, dried and pricked with a fork, then wrapped in a paper towel and placed one inch apart on a microwave rack. Cook according to your oven's guidelines, and turn potatoes once during cooking. Don't exceed the cooking time, as potatoes will continue to cook after they're removed from the oven.

Potato tip - If you’re in a hurry to prepare potatoes but feel that microwaving makes the potato too moist here’s one easy tip: As soon as you come home from work turn on the oven to 400⁰ F and place the potatoes directly on the rack for about 15 minutes, (just enough time to change out of your work clothes). Then pull out the potatoes and put in the microwave and you’ll find that the skin is dry and crispy and the potatoes cook faster.  That way you get the taste of oven baking with the speed of microwaving.

Nutritional Information

1. What makes Idaho Potatoes so good?

Idaho grown potatoes have a high solids content, so there's more potato and less water. The high quantity of starch grains cook to a light, fluffy texture and full, firm appearance when properly prepared.

2. What is the healthiest way of cooking potatoes?

Probably baked with a squeeze of lemon, some salt and pepper. Topping the baked potato with salsa is also a good solution.

3. How do I get the most nutrition out of Idaho Potatoes?

To preserve the Idaho Potato's abundant nutrients, cook with the skins on whenever possible. And steam, rather than boil potatoes.

Save the cooking water after steaming potatoes, as some of the potatoes' nutrients will have leaked into it. Use it to make gravies or bread, or to moisten mashed potatoes.

4. Do Idaho potatoes contain gluten?

No, Idaho potatoes are gluten free and often used as a substitute for people with these types of allergies.

Buying Potatoes

1. What size potatoes should I buy?

Small Idaho Potatoes are best for use in salads, while medium-sized Idaho Potatoes are quite versatile and can be used baked, mashed or fried. Large ones are ideal for French fries or the "meal-in-itself" baked potato.

2. Are there two grades of Idaho potatoes, or two varieties?

There are two grades of potatoes typically sold in foodservice. A No. 1 potato from Idaho comes packed in cartons and has less defects, as well as a nice oval shape with few eyes. The No. 2 potato is commonly used in situations where the overall appearance is not as important such as freshly made French fries, mashed potatoes or hash browns. The No. 2 is packed in burlap bags, plastic or paper bags or can also be sourced in a one-piece box.

There are several varieties of Idaho potatoes, to view the different varieties click here. The largest and best known variety from Idaho is the Russet Burbank, named after scientist Luther Burbank. It has high solids and bakes up dry and fluffy and fries crisp and golden brown. Another popular variety is the Russet Norkotah, which also works well as an all purpose potato but has a slightly moister taste. 

Potato Prep/Cooking

1. Why are mashed potatoes lumpy and sticky at times and not at others?

The individual potato cells are susceptible to breaking down based on the amount of starch in the potato. Higher solids (starch) potatoes have larger cell size and tend to not break down as easily when over mixed versus a low solids potato (such as a red or yellow skinned variety) which has smaller potato cells. Among russet varieties the Russet Burbank from Idaho has usually had the highest solids and lowest moisture so turns out dry and fluffy. In Idaho we are required to list the potato variety on the bag or box.

2. How do I achieve the best results when mashing Idaho Potatoes?

Mashed potatoes have been an American favorite for decades. For best results when preparing mashed potatoes, place a quarter of a lemon in the cooking water to prevent potatoes from breaking up, and cook them in their skins to prevent water logging. After cooking, pull the skin from the end of the potato to remove it easily. While mashing, add warm milk to the potatoes gradually to gauge consistency; then add any other favorite condiments.

3. What's the best way to boil Idaho Potatoes?

When boiling potatoes, it is best to leave the skin on while cooking--the potato will retain more nutrients and flavor. Skins can be removed as soon as the potato is cool enough to hold. Potatoes should be scrubbed before boiling, rather than soaked. Soaking potatoes in water can sap nutrients and flavor. To enrich the flavor of potatoes boil them in a favorite stock, or for a mild, sweet taste, boil in milk. Potatoes boiled in milk should be peeled thinly when cooled. To prevent potatoes from discoloration after cooking, add a touch of lemon juice to the water.

Potatoes should be placed in the cooking water before it is heated. An alternate method is to place fresh potatoes in salted, already--boiling water. Steaming is another popular cooking method that has a similar effect to boiling, but the potato tends to retain more nutrients when steamed because it is not immersed in water, though boiled potatoes do retain more vitamin C. Seasonings of various kinds can be added to the water while steaming potatoes to give them a unique flavor.

4. Can I make a recipe for mashed potatoes that contains cream cheese a week in advance and then reheat to serve?

From a food safety standpoint we do not recommend making any recipe with potatoes and dairy a week in advance. Potatoes are a neutral PH and combined with dairy, especially if done warm and not cooled immediately, could lead to some problems. The mashed potatoes will also turn dark from oxidation for that long, even if refrigerated. Instead, make the mashed potatoes the day before, cool, refrigerate covered, then add in the cream cheese (same weights as butter or margarine) the day of your meal. 

5. Is there anything harmful in eating potatoes raw?

There is no harm in eating the potatoes raw, however, you may find them a little harder to digest than when cooked. Willard Scott, the famous NBC weatherman, does this all the time even making a point once to chomp down on an Idaho Potato on a harvest segment of the TODAY show a couple of years ago.

6. What is the best method to pre-cook mash potatoes and reheat later?

Boil water, add peeled potatoes cut into large chunks, cook and drain. Mash or use a ricer. Add a teaspoon of lemon juice or white vinegar to help keep the potatoes from oxidizing and let them cool then cover tightly and refrigerate. Reheat (microwave, crock pot, oven, stovetop) till slightly warm and then add in the liquids (milk, chicken broth, even a little water to rehydrate can work).

7. What's the best way to open a baked potato?

Never use a knife for opening a baked potato; it flattens the surface and alters the normal fluffy texture of a baked Idaho spud. Instead, pierce the potato with a fork, once lengthwise and crosswise. Press the potato at both ends and it will "blossom".

8. When is a baked potato done?

Potatoes are ready when their internal temperature reaches 208 to 211 degrees Fahrenheit. A fork easily pierces a baker when it's done. If the potato is hard, bake a little longer. However, watch out for over-baking, or drying of the underskin will occur.

9. What is the healthiest way of cooking potatoes?

Probably baked with a squeeze of lemon, some salt and pepper. Topping the baked potato with salsa is also a good solution.

10. When using skewers, how can I prevent the inside of my potato from turning dark?

If you use metal skewers for baking potatoes, heat the skewers first. This seals the potato and prevents the center of the potato from turning dark.

11. How do I achieve the best results when frying Idaho Potatoes?

When frying, the high solids content of Idaho Potatoes decreases oil absorption, guaranteeing crispier potatoes. In addition, Idaho Potatoes shrink less when fried and retain their shape better than moister potatoes.

Before frying potatoes, rinse them in cold water to remove starch, which can cause the potatoes to stick together during the frying process. For crispier potatoes, soak the potatoes in salt water for several minutes before cooking. Be sure to always use clean oil, heated to the proper temperature--food dropped in improperly heated oil will absorb the fat and take longer to cook. Oil should be heated slowly. If a good thermometer isn't available, drop a potato strip into the oil and observe. If it sinks and the surrounding oil doesn't react, the oil isn't hot enough. If the oil bubbles around the strip and the potato remains on top, the temperature is ideal.

Keep checking the cooking oil for acrid odors while cooking; strong odors indicate that the oil is beginning to burn. Be sure to never leave frying potatoes unattended.

12. Can a pressure cooker be used to cook Idaho Potatoes?

What happens when you add an Idaho potato to a pressure cooker? You get the fastest, easiest, healthiest potato dishes in no time. Imagine mashed potatoes in seven minutes or crunchy topped potatoes in four minutes.

A pressure cooker is the ideal cookware for preparing flavorful and healthful foods in record time with little or no fat. By sealing in foods inside the pressure cooker, steam pressure builds inside the pot and the temperature rises. The high cooking level cooks foods in a short period of time, often cooking meals in less than 15 minutes.

Because foods are cooked under pressure, up to 50% more vitamins and minerals are retained. Because steam pressure breaks down the fibers in food in a very short time, foods are succulent, with an intense mingling of flavors.

Check out our Recipes section for pressure cooking recipes or follow this link to find out more about Fagor pressure cookers.

13. Why is my new potato peeler often difficult to use?

A new potato peeler could be difficult to use because the peeler "softens up" with use. The high starch in the Idaho Potato reacts with the peeling blade, making the blade sharper with each potato peeled. The peeler handle also becomes more flexible with use. Idaho Potatoes have a long, smooth shape, so the peeling action is even. As the peeler handle loosens, it can more cleanly slice the surface of the potato.

14. Why do my potatoes sometimes turn black after I cook them?

This is one of the hardest things to detect when potatoes are brought in from the field and sorted to go into bags for consumers.  Black spots just below the skin of the potato can occur if the potato is stored too cold (below 40 degrees) or when a potato is dropped more than 6 inches or something heavy is placed on top of them.  The damage does not appear immediately but can become noticeable after one or two days in storage.  Since the skin is not broken it is very hard to detect black spots until the potato is cooked.  

Despite their hardy appearance, potatoes can bruise as easily as a banana or apple.  While it might not be convenient, you can still eat the potato as long as you trim away the black spots before cooking.

Storing Potatoes

1. Where is the best place to store potatoes?

Store Idaho Potatoes in a cool, dark and well ventilated place. They will keep about a week at room temperature and for several weeks at 45 to 50 degrees Fahrenheit.

However, refrigerator temperatures are too low, which converts the potato's starch into sugar, resulting in a sweet taste. The extra sugar also causes potatoes to darken prematurely while frying. (This process can sometimes be reversed by storing the potatoes at room temperature for a week to 10 days.) If potatoes have green patches, cut them off, as they have been exposed too long to direct lighting and will have a faintly bitter taste. The rest of the potato will taste fine.

Potatoes are still alive when they are picked, so they should be kept in a cool area, away from the light. A cellar is ideal, but any place where they won't be exposed to excessive heat or light will help prevent spoiling.

2. Should I wash my potatoes before storing?

Before storing spuds, look them over and use any bruised ones first. Since dampness can cause decay, it is best not to wash spuds before storing.

3. Can home made mashed potatoes be frozen?

Once mashed they can be frozen but will typically oxidize or turn gray in a matter of days. To help prevent this, add a small amount (tablespoon) of white vinegar or concentrated lemon juice to the mixture once cooked.

4. If I purchased a 50 lb box of potatoes how long would they stay good if stored in proper conditions?

If stored at 45-48 degrees F with 95% humidity the potatoes will last quite some time, potentially months. Most people can not make arrangements to store them under those conditions. Store in the dark, in a cool location and you should be able to have them stay fresh for a couple of weeks. The potato is about 80% water, so high humidity really helps retain the moisture. Above 55 degrees the potato will start to shrink and is more susceptible to sprouting.

General Potato Questions

1. What is the difference between No. 1 and No. 2 Potatoes?

No. 1 potatoes are typically better shaped with less defects than No. 2's.  No. 2 potatoes bake and taste the same but may have pointed ends, more bruising, etc.  Restaurant operators use No. 2 potatoes when the final appearance does not have to be as attractive a potato shape, for example for mashed, hash browns or French fries.

2. When does the Idaho® potato “planting” and “harvesting” season officially begin and end? 

Planting usually starts in early April and goes into middle May, the bulk of the planting happens in the last two weeks of April and the first two weeks of May.  The early warmer areas of the valley start earlier, but they don’t plant nearly as heavily as the cooler areas of the state. Harvest begins in early September and can run through most of October. Most of the potatoes are harvested in the last two weeks of September and the first two weeks of October. Some varieties will be harvested earlier than that, but they don’t account for much production.