Mashed potatoes at Thanksgiving are serious business, but for Chef Barbie Marshall mashed potatoes are serious business no matter when she makes them. Chef Barbie is the in-house caterer at Ruba Club in Philadelphia and currently a contestant on "Hell's Kitchen All Stars." She came in fourth in season 10 of "Hell's Kitchen," and so far she's still in the running to win it this time around.

Chef Barbie Marshall, Hell's Kitchen All StarsChef Barbie took some time out from all she has going on to give me her top tips on making the best mashed potatoes.

"I'm very opinionated about everything mashed potatoes," she told me over the phone when I asked if she'd talk to me about starting the potatoes in cold or hot water. Her passion for potatoes came through as she went way past water temperature once we got chatting.

Just in time for Thanksgiving, here's her advice on how to make buttery, creamy mashed potatoes from start to finish, as well as how to salvage lumpy mashed potatoes and even how to prep ahead.

Cold vs. hot water

pot of cooking potatoes Don't turn your pot of water on until all of your potatoes are peeled, cut and in the pot. (Photo: Adva777/Shutterstock)

As much as I love mashed potatoes, I've never given much thought to whether there's a perfect way to prepare them. I do what my mom did, and mine usually turn out pretty well — but they're not fabulous. One thing I don't do that Chef Barbie says is imperative is to start my cubed potatoes in cold water.

"You absolutely have to start in cold water," said Chef Barbie, "or the potatoes start to cook on the outside before the inside and the starches get water logged inside." The starch is what helps to make mashed potatoes thick so you want the starch in good condition.

Also, starting in hot water will cause potatoes to cook unevenly. The outside can end up overcooked before the inside is fully cooked.

The big takeaway here is to always start with a pot cold water and don't turn on the heat until all your cut potatoes are in the pot.

Type of potato

yukon gold potatoes Yukon Gold potatoes were made for mashing, according to Chef Barbie Marshall. (Photo: photogal/Shutterstock)

"Use Yukon Gold potatoes because they are delicious," said Chef Barbie. "That's what that potato is for — mashing and roasting. It's beautiful."

She has definite opinions on a few other potato varieties.

  • Russet potatoes are to be used in the "worst case scenario."
  • Red Bliss potatoes — or other waxy potatoes — are for making smashed potatoes with the skins on, not mashed potatoes.
  • And as far as using fingerling potatoes, she emphatically said, "No. You will not."

Mashed potatoes from beginning to end

electric beaters A handheld electric mixer fitted with beaters will help create creamy mashed potatoes. (Photo: Thanakrit Sathavornmanee/Shutterstock)

Rather than sharing an exact recipe, Chef Barbie took me through the basic steps that anyone can follow (even if you stray from her Yukon Gold imperative).

1. Scrub and peel potatoes.

2. Cut the peeled potatoes into uniform cubes. The uniformity of the cubes is more important than the exact size, which Chef Barbie says should be a "large dice."

3. Aggressively salt a pot of cold water just like you would for pasta.

4. Put cubed potatoes in the salted, cold water, put on the lid, and turn on high.

5. When the water starts to steam, take the lid off and turn it down a little. You don't need to bring the water to a rolling boil before taking the lid off, just a simmer. You don't want the potatoes "knocking about."

6. Keep the water at a simmer, and the potatoes should be done somewhere between 15 and 25 minutes, depending on the size. To test for doneness, stick a fork in one of the cubes. If the potato slides off the fork, it's done.

7. Turn off burner.

8. Pour off the water.

9. Taste one cube to determine how much salt you'll need later.

10. Put the pan with the potatoes back on the burner, but don't turn it on. Keep the lid off the pot and allow the water left on the potatoes to steam away.

11. Heat your butter and milk, cream or half-and-half. For the holidays, Chef Barbie suggests using cream or half-and-half (which she says many people don't think of as an option for mashed potatoes).

12. Begin mashing with your electric hand mixer with beaters or your hand potato masher. A hand masher will give you the heaviest potatoes. An electric hand mixer will make them lighter. Either is fine. If you want to use a stand mixer, make sure to use the paddle attachment, not the whisk. And, never ever use a food processor or you'll end up with potato glue instead of mashed potatoes.

13. Slowly add butter and cream at a ratio to your liking (if you want potatoes to be more buttery, use more butter. If you want them to be more creamy, use more cream.)

14. When the potatoes are the consistency you want, taste to see if you need more salt. Chef Barbie's personal preference is to not add pepper. (It's my personal preference, too.)

15. If you need to keep your potatoes warm, cover with plastic wrap and then with foil. The plastic wrap will keep the moisture in. You can even put it in the oven like this on a very low temperature to keep warm.

Salvaging lumpy mashed potatoes

mashed potato casserole You don't have to tell anyone the cheesy mashed potato casserole on the table was the result of saving lumpy mashed potatoes. (Photo: minadezhda/Shutterstock)

Lumpy potatoes are the result of potatoes that are not fully cooked.

"You can’t go back and cook potatoes more," said Chef Barbie. But, she does have a method to salvage your undercooked potatoes.

Take your lumpy mashed potatoes and fold in about a cup of sour cream and a cup of cheese. Spread the mixture into a casserole dish that's been sprayed with non-stick cooking spray. Cook at 400 degrees until the cheese melts and the casserole is nice and bubbly. The lumps will then be cooked through, and you'll have a potato casserole that you can pretend you meant to make the entire time.

Planning ahead

peeling potatoes You can peel — and cube — your potatoes up to three days in advance if you keep them in water in the refrigerator. (Photo: Catalin Petolia/Shutterstock)

Here's something I didn't know. You can peel and cube your potatoes and put them in cold, unsalted water in the refrigerator up to three days in advance of making your mashed potatoes. That's helpful to know if you're planning a huge holiday meal.

Before cooking, drain the water from the potatoes, and then add fresh cold water and salt.

For more of Chef Barbie's tips you can follow her on social media. She's @barbiemarshall on all platforms.

Robin Shreeves ( @rshreeves ) focuses on food from a family perspective from her home base in New Jersey.

Everything you need to know about mashed potatoes just in time for Thanksgiving
'Hell's Kitchen All Stars' Chef Barbie Marshall shares her steps to making perfect mashed potatoes, including why starting in cold water is the only way to go.