High-end restaurants have begun adding a new piece of equipment to the kitchen that until recently was found mainly in medical laboratories and university chemistry departments. The bigger versions look a bit like washing machines, but the spin cycle in these ultracentrifuges is a lot more powerful than that of any Maytag. They whirl vials around tens of thousands of times a minute, generating centrifugal forces up to 30,000 times as strong as Earth’s gravity.
You might think that such crushing force would be enough to obliterate any foodstuff, but in fact the intense pseudogravity causes fluid foods such as purees—mixtures of liquids and solids of various kinds—to separate. For example, the meat of centrifuge-pureed tomatoes settles, along with bits of skin, in a compact puck at the bottom of the vial. The water in the tomato forms a clear layer in the middle, and the intensely flavorful oil floats above.
Chefs find centrifuges handy for several reasons. A centrifuge saves a cook time: a separation process, such as extracting the oil from a vegetable puree, that might take days under natural gravity finishes in mere minutes at 20,000 g. The results are also much more predictable than those obtained by natural settling. The biggest selling point for these culinary tools, however, is the amazingly clean division they produce among the components. Because the food emerges from the centrifuge separated into distinct strata, it is easy for the cook to then decant or scoop off the layers he or she wants to use.
In many foods, the high-speed spin concentrates the flavor molecules in a powerfully aromatic liquid layer that is ideal for cooking. A chef might use just the water and oil from a centrifuged tomato puree, for example, to make a consommé that has a brilliantly strong tomato flavor yet is perfectly clear. The cooks in our research kitchen at the Cooking Lab in Bellevue, Wash., have used the ultracentrifuge to make sweet and rich carotene butters from carrots. Indeed, centrifuges are great for spinning fat out of all kinds of vegetables and nuts; you can then use the purified fat to make constructed creams having consistencies similar to dairy cream but with dramatic and unexpected flavors—and because they are dairy-free, they are suitable for vegans to eat.
To make a soup or sauce that is transparent and smooth on the tongue, you must somehow remove solid particles that are larger than the tongue can discriminate: about seven microns (a mere 0.0003 inch) in size. Strainers, filters and other culinary tools can do this, with enough time and effort. But it’s hard to beat the convenience of just pouring the mixture into a bottle, sticking it in the superspinner and pressing “start.”