The first time I had french fries cooked sous vide I was the very fortunate guest of a friend who was writing an article about Asheville. I had to drive separate from him and he was already basically finished with his meal at Nightbell, but he had been so blown away with his meal that he was willing to let me have experience their food as well.
It’s very tempting to relive the whole experience again by writing about it (and it’s great to know that the deviled egg is still on the menu; you can watch this episode of Original Fare to see that deviled egg plus some other really cool stuff), but the one dish that really had me going was a poutine with duck confit and a foie gras gravy. The surprising thing in a dish with foie gras and duck confit, though, was the french fries. The fries had the perfect balance of a crispy exterior, fluffy interior, and were seasoned perfectly throughout that I remember us sitting there trying to figure out how they may have been prepared. Fortunately the chef came out to talk with us and we were able to ask about how they had been prepared.
So sous vide fries are kind of a pain in the ass, I won’t lie.
The process is this:
- Cut the fries and place into bags with a brine (the recipe is at the bottom).
- Cook in a water bath at 194°F/90°C for about 15 minutes, cooking in small batches.
- Cool the fries on a rack.
- Heat your fryer to 266°F/130°C and cook the fries for 5 minutes, again in small batches.
- Again cool the fries on a rack to drain the oil, then freeze them individually (this is an essential step because the freezing helps break down the cellular structure and increases surface area, thus making for crispier fries).
- Heat the fryer to 374°F/190°C and fry the frozen fries until they are golden delicious brown.
My first attempt at this was a hot and watery mess because my Anova precision cooker couldn’t keep the temperature at 194°F/90°C. So I had to keep a pot of boiling water going on the stove to keep adding hot water to the water bath. Not only did I have hot water everywhere, but because I had trouble maintaining the proper temperature I adjusted the time and ended up overcooking the fries so that many of them broke into pieces. And the resulting fries were kind of cooked unevenly. There was definitely potential, and they were marginally better than my usual preparation of brining and double frying, but not as good as my experience at Nightbell.
With my second attempt I achieved the desired result: perfectly crisp fries with a light and fluffy interior. Instead of using the immersion circulator I just used a big stock pot on the stove with a probe thermometer, adjusting the temperature with cold water as needed; which means basically anyone can cook the perfect french fries at home.
But is it worth it? I think it’s an unqualified yes. The process is time consuming to be sure, but you can make a whole lot of fries at once and keep them in the freezer for up to a few months. And they really are the best fries you’ll ever taste.
Here’s the brine recipe (which is lifted straight from Chefsteps.com) per 1.2kg of Russett potatoes cut into small batons (they say 9mm):
- 1 kg of water
- 15 g salt
- 10 g glucose syrup
- 2.5 g baking soda
The trick is to work in small batches, laying the fries out in an even layer in a zip-loc freezer bag using the immersion technique to get the air out. I was able to cook two bags at a time in the water bath, so if you have 4 bags you know it’s going to be half an hour of blanching (8 bags is an hour. . .).