We’ve published hundreds of clever readers’ tips over the years, and every so often, we encounter one that makes us wonder, why does it work? We figured there must be a scientific explanation; after all, science lurks beneath everything we cooks do in the kitchen. So we rounded up some tips we’d been wondering about and turned them over to chemist and food science writer Robert L. Wolke, author of the two-book seriesWhat Einstein Told His Cook,用于解释。这就是他对技巧背后的科学的看法。

A better way to store herbs

Why it works

正如任何兴高采烈的花束接受者所知道的那样，维持花朵以及背后的情绪的最佳方法是将其茎的尖端浸入水中。新鲜草药也是如此。

许多开花的植物和草药（所谓的血管植物）都有一束细长的结构，称为木质部，韧皮部延伸到茎上，将水和养分携带到植物的上部区域。当您将新鲜草药的茎放入水中时，水从这些管中升入叶子，使它们保持牢固。将草药花束放在冰箱中放缓腐烂，因此草药将在两周内保持新鲜。每隔几天更换水，以使细菌和霉菌不在其中占用。

战斗洋葱眼泪

Why it works

Ask almost any cook and you’ll hear his or her pet strategy for preventing tears when cutting onions. “Cut them under water,” some will say, leaving open the question of whether the onions or the cook, or both, are to be submerged. Others may say, “Cut off the root end last,” as if the onion will know the difference and behave accordingly. And then there’s the last-line-of-defense school: Let the irritating gas spread at will, but protect the eyes and nose with a skin-diving mask—a technique I have used with success. (A Speedo bathing suit is not required.)

但是在我告诉你另一个不那么笨拙，防御性的措施之前，让我解释为什么洋葱让我们哭泣。

The tear-producing gas is a chemical called (among other names) thiopropanal sulfoxide. It doesn’t exist in whole, intact onions. Instead, it forms at the time of cutting, when an enzyme (alliinase) and certain other chemicals (sulfoxides) escape from the broken cells and react with one another in the air to form the thiopropanal sulfoxide vapor. When this vapor reaches the eyes, it dissolves in our alwayspresent film of tears. This irritation stimulates the tear glands to try to wash the offending substance away.

那么，任何事情都可以消除或至少减少眼泪吗？尝试一下：在切割之前将洋葱冷藏一两个小时。所有化学反应，包括产生洋葱催泪瓦斯的化学反应，在较低的温度下放慢速度。如果洋葱很冷，则气体会更少，眼泪较少。

但是，如果您想坚持使用其他一些宠物方法，那也很好。如果对您有用，请继续前进。

Make your own buttermilk

Why it works

在紧要关头，这个技巧将起作用，但是，正如我要解释的那样，这并不总是最好的行动方案。添加醋（乙酸）或柠檬汁（柠檬酸）等酸，以使蛋白质凝结并使牛奶味道酸。但是酸味的牛奶和酪乳并不是一回事。真正的酪乳是通过在牛奶中添加活乳杆菌来培养的。这些细菌以乳糖，牛奶糖为食，并产生乳酸，该乳酸会部分凝结和浓稠牛奶，并使其具有独特的，浓郁的味道。然而，用醋或柠檬汁酸味的牛奶味道像醋或柠檬汁。

You can easily substitute soured milk for buttermilk in a recipe where the buttermilk’s primary function is a chemical one: for example, in a cake batter where the buttermilk is the acid that reacts with the baking soda and creates the carbon dioxide gas that helps the cake rise. But in recipes for buttermilk biscuits or pancakes or salad dressing—that is, any recipe where buttermilk’s unique lactic-acid flavor and consistency is key—only the real thing will do.

在微波炉中软化红糖

Why it works

这是一个经典的提示，至少是因为微波炉入侵了我们的厨房。红糖由糖颗粒组成，几乎类似于您的糖碗中的砂糖，但添加了少量的糖蜜。当暴露于空气时，糖蜜会干燥并变硬，将谷物固定在一块甜混凝土中。来自微波的热量使糖蜜水泥的变软足够长，可以使您测量糖，但是它会在冷却时再次变硬。

A more permanent fix is to restore the brown sugar’s lost moisture by sealing it in an airtight container along with a wedge of apple or a piece of dampened paper towel (keep a sheet of plastic wrap or aluminum foil between the towel or apple and the sugar). The molasses will soften over a period of several days as moisture from the fruit or damp paper raises the humidity in the container

快速解冻食物而没有头

Why it works

This is a great tip, and people are often astounded at how well it works. But heating the pan with hot water isn’t even necessary. You can thaw frozen food quickly simply by placing it on a heavy metal surface at room temperature. This works because metals very efficiently conduct heat from the surrounding air into the food. The heavier the pan, the more heat it can conduct, and the faster the food will defrost.

Copper and aluminum are the best heat conductors, but if a solid copper or heavy aluminum pan isn’t handy, a heavy stainless-steel pan with a thick copper or aluminum core will work very well. A cast-iron pan would be the next best option. A solid stainless-steel pan isn’t a great choice because stainless steel doesn’t conduct heat as well as the other metals. And a nonstick pan is even worse because its Teflon lining is a heat insulator—but there’s nothing to prevent you from using it upside down.