Starch-Infused Fries - Modernist Cuisine

Starch-Infused Fries

Recipe • November 23, 2011

When Nathan, Chris, and I were writing Modernist Cuisine, we knew that two great techniques had recently been created for making French fries: one by Heston Blumenthal of The Fat Duck in the U.K. and another by Dave Arnold and Nils Norén at the French Culinary Institute. So we decided to include in the book recipes inspired by both of those teams. Our pommes pont-neuf is similar to Blumenthal’s triple-cooked chip. Arnold and Norén built their technique from a Polish researcher, Gra?yna Lisi?ska, who discovered that steeping potatoes in a pectin-dissolving enzyme creates a great fry texture, and that technique is illustrated by our pectinase-steeped fries recipe.

Then we started musing about other methods we could try to make the ultimate French fry. It occurred to me that we had an ultrasonic bath that we hadn’t used much for the book, except as a handy tool for extractions. I thought perhaps the cavitating action of the ultrasound would create an interesting texture in the fries. So, after cooking the potatoes sous vide to a nice, tender consistency, we put them in the ultrasonic bath. And sure enough, the cavitation created thousands of little fissures on the surface of the potato, which effectively released all of the natural potato starch. When we then deep-fried the potatoes, we could see the starch come out and crisp up to form tiny hair-like fuzz on the outside of the fries. They had an amazingly satisfying, crispy texture.

Having succeeded in finding a way to get the natural starch out, it got us thinking about ways to stuff more starch into the potatoes. We realized that we could use vacuum packing to infuse starch into the potatoes to produce an extra layer that would allow the interior texture to remain silky as the exterior fried and dried to a crisp. The next logical step, of course, was to marry both methods together into a recipe for starch-infused ultrasonic fries. They’ve been a big hit when we have served them at our dinners and events.

In the end we published all four recipes for French fries (five if you include the pommes pont-neuf). Each differs somewhat from the others in it texture and fluffiness, but all of them are great. The recipe for Starch-Infused Fries here is one of the simpler ones. If you want the others, you’ll have to buy the book!

Although these recipes represent the successes of our many rounds of trial and error, not all our ideas panned out. Our seemingly brilliant idea of infusing fried with ketchup or vinegar, for example… well, let’s just say that they’re not in MC for a reason.

Maxime Bilet, coauthor of Modernist Cuisine and Modernist Cuisine at Home


Make sure to vacuum seal your potatoes in one even layer so that they cook evenly. Chefs have been deep-frying their potatoes twice--first at a lower temperature, then at a higher temperature--for years. But Heston Blumenthal came up with the idea to cook the potatoes before frying them at all. Not only do our starch-infused fries have a crispier exterior, but they keep their crispiness longer, too! Our starch-infused ultrasonic fries offer the best of both worlds: an ultracrispy exterior and silky fluffiness inside. We recently served this ultrasonic fry at a Cooking Lab dinner with bone marrow mousseline.

Tips and Substitutions

  • Fries need to be preseasoned with a brine. Add salt (about 1.5%–2% of the total weight of the potatoes) before you vacuum seal them. We have found that this is essential because salting the fries when they are done cooking actually softens them over the course of about 15 minutes.
  • When vacuum sealing the cut potatoes, make sure they are in one even layer. They will cook more evenly this way.
  • Make sure to cool the fries completely between steaming and each round of deep-frying.
  • Cooling the fries in a chamber vacuum sealer both cools and dries the exterior of the fries–one of the methods developed by Heston Blumenthal. You can, however, air-dry your fries. Simply place the fries in a single layer on a rack. You can use a household fan to speed up the process, but it will give the fries a thinner crust.
  • We like to use our combi oven to steam our potatoes, but any method will work.
  • We use a 21 l / 5½ gal Branson 8150 ultrasonic bath set at a frequency of 40 kHz.
  • We recommend both the Waring Pro DF250B 1800-Watt Deep Fryer and the Waring Countertop Electric Commercial Deep Fryer.
  • Chefs have been deep-frying their potatoes at two different temperatures for years, but Heston Blumenthal discovered that cooking potatoes before frying lends a mashed-potato-like texture to the fry interior. Blumenthal recommends par-frying the cooked potatoes once at 130 ?C / 265 ?F, drying them, and then frying them again at 200 ?C / 390 ?F. We find these temperatures a little low when making pommes pont-neuf. We have also stuck to the traditionally prescribed temperatures in our other French fry recipes.
  • Infusing the fries with starch not only makes them crispier, but also helps preserve the crispiness longer. To avoid soggy fries, sprinkle on spray-dried vinegar instead of dowsing them with liquid.
  • Looking for a condiment more creative than ketchup? We recently served these fries with a bone marrow mousseline, but you can also find us eating them at The Cooking Lab with leftover mushroom marmalade from our striped omelets!
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