A commenter named luis in another post criticized the element “shock” in the new book for being too brief. Of course every term has an infinite level of nuance, but the point of The Elements of Cooking is to provide a concise glossary of cooks terms. Nonetheless, for luis and others, here are three linked terms. Shocking fruits, vegetables, pasta and other foods is one of the most important acts a cook performs.
Blanch: This word has several different meanings depending on who’s using it and why, so it almost always needs some qualification or explanation. Technically, to blanch means to plunge a fruit into boiling water for a minute or less to make the skin easy to peel (as with a tomato or a peach) or to change, or “set,” a green vegetable’s color from flat to vivid green while keeping it, in effect, raw. Some kitchens use the word to mean parboil, to cook a vegetable half way, then shocking it so that it can be finished later. French fries are often blanched in low temperature oil so that they can be finished quickly (and crisply) in hot oil later. Many chefs use it to mean plunging a vegetable into heavily salted water that’s at a rolling boil, fully cooking that vegetable, then removing it to an ice water bath. To blanch can also mean to cover bones with cold water and bring them to a boil, then strain and rinse them in order to clean them for a white stock.
Shock: To shock means to plunge into ice water in order to halt the cooking. Green vegetables, such as the broccoli above (thanks donna!), are commonly boiled in salted water and immediately shocked.
Refresh: 1) To rejuvenate a dish or a sauce by adding fresh ingredients. Stock based sauces can be refreshed for instance by adding more stock and fresh herbs. 2) Some cookbooks and recipes use “refresh” as a synonym for “shock,” plunging cooked food into an ice bath to stop it from cooking. Avoid this illogical term; use shock, which is more accurately descriptive.
Chef Pardus, who read and commented on the entire manuscript, responded to luis on the other blog and I’ll put some of his his comments to luis here. I like his note about the carryover cooking (another important term!) of nuts (or anything especially with a high fat content). It's all about heat control.
"I think that we assumed a level of knowledge/experiance among readers that we should not have - i have to be very careful of this when I am teaching - easy for me to assume that because it seems simple and self evident to ME that a brief explanation will suffice for my students. You cook what ever it is - broccoli rabe, egg, pasta, shrimp - until it is cooked to your specification for a particular need (par-cooked, half cooked, JUST cooked...)and then immediately remove it from the cooking liquid and plunge it into ice water to arrest the cooking. Leave it in the ice water until it is COLD to the touch and then remove and hold cold/cool until you need to use or reheat it.
"It's not the same thing, exactly, but worth noting that roasting seeds and nuts will over cook if allowed to brown perfectly and THEN removed from the heat source and left in the hot pan they were roasted in. Obviously you can't plunge them into ice water, but you should have a cool metal pan on which to spread them out so that they can cool quickly without over browning - in effect, "shocking" them to quickly arrest the cooking and color change before it goes too far."