Spheres, Foams and Gels
Farzi café in Gurgaon has some wacky stuff on its menu. The first dish they serve is an amuse bouche which they called Mishti doi shots. It comprised a small bowl with a light brown orb, some strawberry compote and a sprinkling of panchphoron. We downed it like a shot, and much to our fascination, the orb gently exploded in our mouths releasing a gush of a mishti doi flavoured liquid, accented with the sharpness of the compote and the texture of the panchphoron. It is a great example of how molecular gastronomy can be used to create unique and interesting dishes. This week, we will explore the playful side of molecular gastronomy.
Let us start with spherification, one of the most well-known techniques in molecular gastronomy. To any flavourful liquid such as fruit juice, powdered sodium alginate is added. The liquid is dropped into a cold solution of a calcium salt (chloride or lactate) with a needle-less syringe. Just as a drop of water remains as a sphere when put into oil, this alginated liquid remains as a drop in the calcium salt solution. A reaction occurs converting the outer layer of the alginated liquid sphere into a thin skin. These spheres are carefully retrieved and washed in water to get rid of the excess calcium salt. What we end up with are tiny liquid-filled spheres that burst in the mouth.
A more ambitious technique using the same principle is reverse spherification, which involves pouring the alginated liquid into moulds like those used for making chocolates, and freezing them. These frozen pieces are then dunked into the lactate solution. The frozen liquid slowly melts and simultaneously, the thin jelly skin forms retaining all the liquid inside. These are then delicately retrieved and washed in cold water as usual, and served immediately. It is a great way to serve drinks like mojitos, and was the basis for the mishti doi amuse bouche we talked about at the start.
Another staple of the molecular gastronomy kit is lecithin powder, used in making edible foams. We’ve already talked about lecithin in our egg series. It is what holds the water and oil together in unexpected harmony in a mayonnaise. Lecithin has yet another property; it lowers the surface tension of any liquid it is added to. You will recall from high school physics that it is a low surface tension which causes soap water to froth. Lecithin creates the same effect; add it to any liquid and agitate it with a hand blender, and an edible lather forms on top. Retrieve it gently and quickly, and use it to garnish any dish of your choice.
A much sturdier foam can be made using a whipped cream canister. The liquid is mixed with pasteurized egg whites and added to a canister charged with nitrous oxide gas with converts the liquid into a foam. One of Heston Blumenthal’s earliest creations was an amuse bouche that involved taking a green tea and lime flavoured liquid, converting it into a foam and dropping dollops of it into liquid nitrogen, which sets the exterior. These are then dusted with matcha powder and served immediately. When eaten, the warmth of the mouth melts the shell releasing the foam of flavour that dissipates in the mouth almost immediately, leaving the mouth fresh, while the residual gas issues, dragon like, out of the nostrils in the form of vapour.
We’ve talked about spherification earlier. A cheat’s alternative would be to use a gelling agent like gelatin or agar agar. It involves mixing the liquid with agar agar, and pouring it drop by drop into a bowl of cold water using a syringe. The individual drops, upon contact with the cold water, set immediately producing tiny jellied spheres, perfect for garnishing a dessert. Another playful agar-based concoction involves mixing fruit juice with agar and slowly pushing it into a tube using a syringe. The tubes are then submerged in ice water to set the jelly. When set, extrude the strands of jelly using an empty syringe and voila, you’ve got fruit spaghetti.
But perhaps my most favourite application of agar in molecular gastronomy is the fluid gel. A jelly is made with agar and blitzed till smooth. It is then sieved, and if possible, put in a vacuum chamber to remove the excess air. What you get is a clear gel which is easily spreadable yet holds its own. Sturdier than a coulis and thinner than a jelly, the closest thing I think of texturally is the ultrasound gel I use at work. Fluid gels have a unique texture and is great in both sweet and savoury applications.
Let us end with the examination of an amazing dish I came across in a blog called Gratuitous Foodity. Playfully named the Peaness Mightier, it takes the centrifuged pea puree we talked about last week to the next level. The puree is centrifuged and separated into pea broth, pea butter and pea solids. The starchy pea solids are dried out in an oven and pulverized to make pea flour. This flour is then used to make crackers, which are then slathered with the pea butter and topped with caviar made with the pea broth. If there is a dish that marries nose to tail cooking and molecular gastronomy, it has to be this. Check out the recipe here https://www.gratuitousfoodity.com/2012/01/17/the-peaness-mightier/
Molecular gastronomy is here to stay. It will never replace traditional cooking, but it has created its niche in the gastronomic universe, and it worth the effort to cross the fourth dimension and enter the mysterious terrains of this truly enchanting domain of modern cooking.