How to Make French Fries (Ultra Crispy at Home)

Clip your immersion circulator to the side of a large pot or polycarbonate tub, fill it with warm tap water past the minimum line, and set the temperature to 90 degrees Celsius (194 degrees Fahrenheit). Give it ten or fifteen minutes to come up to temp while you work on the brine and the potatoes. Ninety degrees is the sweet spot - hot enough to cook the potato all the way through, but low enough that the exterior never browns, which is what lets the second fry crank up to 375 without burning the outside.

Pour four cups of cold water into a large mixing bowl. Whisk in one tablespoon of kosher salt and a half teaspoon of baking soda until everything dissolves. The salt seasons the potato all the way through during the sous vide pass. The baking soda is the part most home recipes skip - it gently raises the surface pH of the potato, which roughens the exterior during cooking. That rougher surface is what catches oil during the second fry and turns into the craggy outer crust you bite through on a great french fry.

Tear off a big sheet of parchment paper and lay it flat on the counter. Stand over the parchment and peel your four large russets so all of the peels land on the paper. When you are done, grab the corners of the parchment, lift, and tip everything straight into the trash. No more sticky peels glued to a wet counter, jammed in the disposal, or stuck to the bottom of the sink. Russets are the right potato for this because their high starch content turns into the fluffy interior you want, and their low water content lets the exterior actually crisp.

Lay a peeled potato on the cutting board and slice off a thin strip from one long side so it lies flat. Cut the potato lengthwise into half-inch-thick planks. Stack two or three planks at a time and cut them lengthwise again into half-inch-wide batons. You want even rectangles that measure half an inch by half an inch on every side. Even cuts cook evenly - if some fries are fat and some are skinny, the thin ones burn while the thick ones are still raw inside.

Split the cut fries into three roughly equal piles. Drop one pile into a vacuum-seal bag and pour in just enough brine to cover the potatoes. Seal the bag using a vacuum sealer or a hand-pump zip bag - the goal is to get the air out so the fries sit at the bottom of the bag and do not float to the top when you put them in the water. Repeat with the other two piles. Working in thirds keeps each bag thin so heat moves through the water and into the potato evenly during the sous vide pass.

Drop the three sealed bags into the 90-degree-Celsius water bath and set a timer for 15 minutes. When the timer goes off, pull the bags out, cut them open over a wire rack set in a sheet pan, and spread the cooked fries out in a single layer. The fries should be fully cooked - tender if you bite one, but not falling apart. Let them sit on the rack until the exterior is dry to the touch. Dry exterior equals crispy crust. Wet fries spatter, drop the oil temperature, and steam instead of fry.

Pour two quarts of neutral oil into a heavy Dutch oven and clip a deep-fry thermometer to the side. Heat the oil to 270 degrees Fahrenheit over medium heat. When it is up to temperature, lower in a single layer of fries using a spider strainer - work in small batches so the oil temperature does not crash below 250. Fry for five to seven minutes, gently jostling them, until the exterior looks dry and crusty but still has not picked up any color. Lift them out, drain on a wire rack, and spread them on a sheet pan in the freezer for at least 30 minutes (or up to a week).

Crank the same oil up to 375 degrees Fahrenheit. The fries can go straight from the freezer into the hot oil - the cold makes the second fry shorter and the crust crispier. Lower in a batch and fry for about a minute and thirty seconds, just until they turn a deep golden brown. Pull them onto a paper-towel-lined tray and immediately sprinkle on a heavy pinch of kosher salt while the surface is still glossy with oil. That is when the salt sticks. Salting cold fries means the salt just falls off and pools on the tray.

If you want to dress these up the way Joshua does, mix the topping while the second fry is happening. Stir together a half cup of finely chopped fresh parsley, a half cup of freshly grated Parmigiano-Reggiano or Grana Padano, and one freshly grated garlic clove. Add a small pinch of salt and stir to combine. The second the last batch comes out of the oil, toss the hot fries with the topping in a wide bowl so the cheese melts a little and clings to every fry. Pile them on a plate and serve. The combination of crispy salty fries and sharp grassy topping is the move.