This week at the lab day I tried out a recipe that I had read about and never thought I’d be able to try for myself – Heston Blumenthal’s famous triple-cooked chips. You’ll find versions of these in pubs all over the country but Heston claims to have invented them at The Fat Duck. His idea was to take the idea of a fluffy centre and crispy outside to their extremes to create the perfect chip.
A standard chip recipe is roughly as follows: Cut potatoes into equal batons of the size of your choice. Deep-fry them once at 130-140℃ until soft (around 10 minutes depending on the size). Take them out, drain off excess oil and cool. Then fry them again at 190-200℃ until golden and crispy which takes just a minute or so making them perfect for restaurant service.
In The Fat Duck Cookbook Heston tells the story of how he tried various methods to create the perfect chip. For the fluffy middle he found the best way was to boil them in water to get the potato very soft, in fact he advises cooking them until they are almost falling apart. This also produces cracks in the surface which help to crisp the chip. He also tries different methods to dry the potatoes out in order to make the cracks even more pronounced and therefore create a crispier. After trying them in a dehydrator and in the oven he settled on putting them into the vacuum sealer to remove the water that way as it was the easiest way to achieve the result. Our plan was to freeze-dry the chips and see what effect this had. This process removes all the water from the chip, it is the same process used for making stock cubes and dried soup which can be reconstituted with hot water so it would be interesting to if this made the chip even more crispy.
The first job was to cut the chips into equal batons. Its important that they are exactly the same otherwise they will not cook at the same rate. Next the chips are boiled in salted water until they are almost falling apart. This is quite tricky to get right as if you leave them in for a minute too long they will fall apart and they won’t be chips anymore. When they are ready they are removed to a cooling rack.
The next stage is to place the chips in a vacuum chamber on a wire rack and activate the vacuum cycle four times. The suction applied by the machine removing all the air from inside the chamber is suppose to also suck out a lot of the water and dry the chips out. When they came out they were cool and strangely clammy to the touch. Some online recipes call for placing the chips in the freezer for an hour, but we tried this and it did not produce anywhere near as pronounced an effect. I had to use a cheese grater as I couldn’t find a wire rack that would fit in the machine. The important thing is to make sure there is air all the way round the chips so it was an adequate substitute.
Next the chips are fried as normal chips would be at a low temperature of 130℃ for 8 minutes. They are then removed onto a wire rack and vacuum cooled again three times. Then they are ready for service and can be stored in an air-tight container until ready to use or fried at 190℃ for a minute to serve.
The result was very different from a normal chip. They felt very light when picked up due to the lower water content and had an interesting flaky texture in the centre. The chips were very crispy and tasted a little more like a crisp than a normal chip. I think this is because there was more surface area in all the cracks to go criipy and less soft potato centre. Although they are definitely very pleasant to eat I wouldn’t call them perfect. They are so different from normal chips that they are not really comparable. Some people like thin-cut fries, some people like thick cut ‘chip-shop’ chips, and I’m sure lots of people like triple-cooked chips so ultimately it’s down to preference and maybe you could take into consideration the effort required. These chips are not quick to make and they have to be handled with great care or they break. Plus you have to have some very expensive equipment to start with.
The chips that we freeze-dryed were very strange. They browned in the fryer after just a few seconds and made no noise or oil splutter when they were dropped in. This is because there was no water in them at all. They were very light and reconstituted in the mouth to give a texture almost like a ‘chipstick’, a type of crisp I remember from when I was a kid. The taste was quite like a normal ready salted crisp. It was an interesting experiment but not an improvement on Heston’s recipe in my opinion.