Never thought of making stock from doughnuts for dessert? How about carbonating fruit before it becomes juice? It turns out that these exercises in sweet molecular gastronomy aren’t limited to the lab-like pro kitchens of their inventors–they’re fun projects you can undertake in your own kitchen.
Awall25 says doughnut soup is a lot of fun to make, and tastes “exactly like a doughnut, except it [is] somehow richer than a doughnut.” To accompany the doughnut soup, he made espresso foam, a neat effect achieved without high-tech or hard-to-come-by ingredients. Simply add a bit of soy lecithin, which you can buy at health food stores (get it in liquid form if you can–otherwise, you’ll need to dissolve granules in the coffee) and froth it with a stick blender. The soy lecithin helps the bubbles hold once it’s frothed.
If you luck into some dry ice, or have a handy local source, you can carbonate fruit. When dry ice melts, it turns directly into carbon dioxide, the stuff of carbonation, and with the proper set-up, you can put the bubbles inside your berries. jsaimd tried it with apple slices and said it was like having Martinelli’s sparkling cider in whole-fruit form!