If you're going to be in New York City next Tuesday, there are still a few tickets left to the Kitchen Alchemy duo's class, "Chilling Out With Liquid Nitrogen."

Did PopSci's recent article on cooking with liquid nitrogen pique your interest? Learn first-hand from H. Alexander Talbot and Aki Kamozawa how to flash-freeze foods and shatter them; turn any cream into ice cream; grind olives into powder; and other kitchen-tech wonders.

The class is at Manhattan's Astor Center, August 26 at 6:30 pm. Use the secret discount code POPSCI when ordering your ticket and get 10 percent off.

Hope to see you there!

In kitchens all around the world, cooks are experimenting with liquid nitrogen. It is a dramatic and very useful culinary tool that can cool or freeze things in an instant. It is made of pure nitrogen in a liquid state. Daniel Rutherford discovered the element nitrogen in 1772. It makes up 78.1% of the earth's atmosphere by volume. In its gaseous state, nitrogen is odorless, colorless, non-flammable, non-toxic, and largely inert. Nitrogen is found in organic materials, foods, explosives, fertilizers, and poisons.

I think that everyone in New York City read last week's article by David Leite on the Quest for the Perfect Chocolate Chip Cookie. One of the main tricks from the article is to rest your dough for 36 hours before baking the cookies in order to improve the flavor. In my work as a chef I have often made cookie dough in advance and baked to order. I knew that refrigeration had beneficial effects although I had never tested the theory to the extent that David Leite did for the article.

Pectin is probably most recognizable to home cooks as the ingredient that thickens jellies and jams and gives them that smooth, sticky texture. Pectin is an indigestible soluble fiber which, when combined with water, forms a colloidal system and gels. It has a wide range of uses. It can be found as a gelling, thickening or stabilizing additive in food, an ingredient in laxatives, a demulcent in throat lozenges, and vegetable glue for cigars.

We are proud to introduce today the first installment of our newest regular feature,Kitchen Alchemy. In it, H. Alexander Talbot and Aki Kamozawa, a husband-and-wife cooking duo and authors of the constantly fascinating Ideas in Food blog, will take us through the myriad intersections of food and science; and as an added bonus, each column will also feature an innovative and, needless to say, delicious recipe for putting said science into action. Enjoy. —Eds.

Pressure cookers are among our favorite culinary gadgets. We like them for things as simple as perfectly steamed beets and as playful as caramelized yogurt. And the days of screeching, squealing pressure cookers, shuddering on your range top and conjuring fears of explosions, are on the wane. Today we have quiet, efficient appliances that are used in both professional and home kitchens. Now you can buy electric pressure cookers, which shorten cooking times, are easy to clean and make a minimal amount of noise.