The lab’s most recent publication, Modernist Cuisine at Home, is nominated for a James Beard Award. The techniques and equipment it champions, however, may require some explanation for anyone more ‘at home’ in a kitchen than a science laboratory. Assisted by a handful of experienced chefs including several The Fat Duck alumni, I went about mastering the lab’s culinary gadgets and created tantalizing recipes using a centrifuge, a rotary evaporator, a Pacojet, an immersion circulator, and a vacuum sealer the size of a photocopier.
Let me explain each time a new technique and share a recipe, now on to Fig Juice in a Centrifuge.
Equipment & Technique
In the washing machine-sized centrifuge at the Modernist Cuisine kitchen, centrifugal forces push food up the sides of several 500mL containers inserted in a heavy, rotating, metal insert. The spinning rotor insert acts like a Round-Up amusement park ride, pasting the food to the side of the containers. But it also spins so fast that it separates the food by density into distinct layers of starch, fat, and juice. The densest particles (in the case of figs, the seeds) fall to the bottom, and the least dense (the juice) rise to the top.
If you’re new to centrifuging, you should probably not buy a centrifuge on ebay to make this recipe. If you do find a secondhand centrifuge, find out about its work history. If it once belonged to a physics or chemistry lab and potentially held dangerous bacteria or chemicals, you’re better off with a high-powered blender. There’s also the little problem of potential death. If the rotor is chipped or the machine is improperly used or calibrated, the extremely heavy rotor may shoot out of the machine at 27,000Gs (27,000 times the force of gravity). If that happens, the last thing you’ll be worried about is getting the fig stain off your shirt; however, Jim, a Modernist Cuisine cooking forum commenter, says that while he’s aware he could start the next plague or kill himself and everyone he knows, he does so enjoy his centrifuged clarified lime juice margaritas
There are two main types of centrifuges. At the Modernist Cuisine lab, the floor-model centrifuge has a fixed angle rotor rather than a swinging bucket rotor wherein the containers spin on an angle. Either model works for this recipe so long as the machine can reach at least 3,500Gs and has a cooling capacity. The lazy machine tends to works up a sweat at even 3,500 times the force of gravity. Counter-balancing the containers within the circular rotor is essential, which is why you can run the machine with two, three, four, or six containers, but not one or five. Lab chef, Aaron Verzosa, says you can use another filled vessel as a counter-balance but the density must be the same. A counter-balance of water will have its weight evenly distributed throughout, but the figs will be denser at the bottom where the seeds and starch concentrate, throwing off the balance as the food separates.
"So if we counter-balanced our fig juice with a container of water would we be in trouble?" I ask. “Maybe, maybe not,” replies Verzosa as he hauls up the backbreaking rotor. “Who’s to say? There are videos of these rotors flying out of the machine.” Fortunately nothing explodes when he turns on the machine, and I’m much calmer an hour later when we have miraculous fig juice, fig butter, and seeds.
A sweet, pure fig juice. Spread the fig butter on scones or serve with a cheese platter or fois gras. Eat the syrup with a spoon, on ice cream or fruit, or as a sauce for red meat or wild game such as duck, venison and bison with a squeeze of lemon.
Recipe: Fig Juice (click here for the preparation)
A high powered blender won’t separate the fig into three distinct layers, but if you don’t have a centrifuge (and who has a centrifuge?) you can make a low-yield fig juice by blending figs then passing them through a fine-meshed sieve or cheesecloth. Or use a juicer, but expect to have more pulp than syrup.