As a food scientist, I’m always on call to handle my friends’ and family’s recipe emergencies, but this time of year the phone rings more than usual: “My grandmother is from Germany, and her recipes use potato starch to thicken everything—can I use flour instead?” Or, “One pie calls for tapioca and another flour— does it really make a difference which I use?”

最常用的淀粉（至少在这个国家）用于增稠锅调味料，肉汁，布丁和馅饼馅料是面粉，玉米淀粉和木薯。不过，它们的行为并不是一样，因此在您替换另一个方面之前，对一般的淀粉以及特定方面的每个淀粉都了解一点很有帮助。

什么是淀粉？

Starches are long chains of sugar molecules—thousands of molecules long, in fact—that are found, in the form of tiny, dry granules, in all plants. The starches we commonly use in the kitchen come from grains (wheat and corn) and roots (potato, cassava, and arrowroot).

淀粉如何变稠？

Starch granules don’t dissolve in cool or tepid liquid—stir some cornstarch into cold water and you’ll see what I mean—but when heated in a liquid, the granules swell, absorb water, and burst, emptying more starch molecules into the liquid. (Every starch granule is jam-packed with starch molecules.) The liquid then thickens because of the traffic jam of tangled molecules and also because the starch molecules sop up water.

全淀粉开始在140°F左右变稠。但是，为了达到充分的增厚能力，面粉和玉米淀粉具有很高的淀粉分子，称为链淀粉，必须一路煮沸，并保持在沸点以下几分钟以煮熟的淀粉味。木薯和其他根淀粉，富含另一种称为淀粉蛋白的淀粉，在沸点煮沸之前呈增厚。

Prolonged cooking and stirring as well as exposure to acids like lemon juice, wine, and vinegar weaken all starches’ thickening power. Different starches, however, can endure different amounts of heat, agitation, and acidity before they start to break down and lose their thickening power. And there are a few other differences worth learning about, such as clarity, cooking characteristics, and how well they freeze and thaw.

是什么导致块状肉汁和调味料？

由于淀粉在温暖的温度下膨胀并凝胶化，因此将它们直接撒入热液体中不是一个好主意。粉末状淀粉的外边缘会立即凝胶化，几乎将其余的淀粉封闭并导致肿块。从本质上讲，淀粉的外表面在淀粉有机会分散和溶解在液体中之前煮熟。为了防止结块，请将淀粉搅拌成一小剂的凉水，然后将此淀粉浆液搅拌到要加厚的热液体中。

Three common thickeners: flour, cornstarch, and tapioca

	Flour	玉米淀粉	Tapioca
	面粉是食谱中最常见的增稠剂，从火鸡肉汁到苹果派，这是有充分理由的：它的多才多艺，在大多数厨房中，它总是在手头。但是面粉不是纯淀粉（它包含蛋白质和其他成分），因此它只有其他淀粉的增厚能力的一半。用作增稠剂的最佳面粉是通用面粉，因为淀粉的含量高于其他小麦面粉。	玉米淀粉is a pure starch derived from corn. It can withstand a good amount of cooking and stirring before it begins to break down. That’s why it’s frequently used for thickening vanilla pastry cream, banana-cream pie filling, as well as butterscotch and chocolate puddings, all of which are cooked on the stove and involve prolonged heating and stirring.	Tapioca is a pure starch derived from the root of the cassava plant, and it comes in many forms. The small granules of pearl tapioca, labeled instant or quick cooking (Minute Tapioca is a common brand), are widely available and work well as a thickener. There’s also a powdered variety, which dissolves more smoothly than the granules but is hard to find; I get it at health-food stores.
外貌	面粉中的蛋白质使面粉粘稠的调味料和馅饼馅料看起来多云。	玉米淀粉厚的调味料具有半透明的闪光。	木薯粉厚的填充物是晶状的，并且与其他淀粉变稠的填充物相比，果冻状的稠度更像。即时的木薯颗粒不会完全溶解；它们可能会徘徊在馅饼馅中，如柔软，清晰的珠子。
何时使用	面粉最适合不会在视觉上遭受不透明度的食物：白色调味料，例如贝加梅尔，简单的锅肉汁，牛肉炖肉，鸡肉炸鸡肉和苹果或梨派。	玉米淀粉是精致的酱汁和gravie伟大s that you want to be translucent, like stir-fry sauces. It’s also a good choice for berry and stone-fruit pies, because it won’t cloud the jewel-like colors of the fruit juices. Since it can handle a good amount of heat, it’s fine for stove-top puddings and sauces that will be reheated.	It thickens juices faster than flour or cornstarch, so tapioca is great for all fruit pies, especially berry, peach, and rhubarb, which throw off a lot of juice. It’s also great for pies that will be frozen and reheated, because tapioca holds liquid, so the pie filling won’t weep when frozen and thawed.
何时不使用	清晰度很重要的浆果馅饼或调味料	不要将其直接撒在热锅中以作为肉汁，因为它会块。	Don’t use instant tapioca for pies with open lattices or large steam vents because the granules will be exposed directly to the hot air of the oven and won’t dissolve. It’s also not ideal for pan sauces or stovetop custards because it can’t withstand a lot of stirring and boiling.
如何使用	有很多方法可以将面粉用作增稠剂 - 这是很棒的事情：您可以在添加炖液之前在锅中用芳香蔬菜烹饪。您可以在褐色之前将炖肉浸入面粉中，然后面粉会使炖肉变稠。您可以将其与少许液体混合形成糊状，然后将其搅拌成沸腾的锅酱。您不应该用面粉做的一件事是将其直接扔进热液体中 - 干颗粒可能会汇合在一起。 为了达到充分的增厚功率并消除了原始面粉的味道，必须将面粉加热的混合物煮沸，然后煮约3分钟。但是，不要对烹饪过度过度，因为面粉会冷却更多。通常，当它们比理想的稠度稍薄时，停止烹饪肉汁和调味料。	玉米淀粉比任何其他淀粉都更容易在暴露于热液体时结块。为了避免结块，将玉米淀粉与一些有助于将颗粒分开的东西混合在一起。对于馅饼和蛋ust，将其与糖相结合，以更好地分散。对于调味料，将玉米淀粉与食谱中需要的一汤匙或两个液体混合 - 液体应该很酷。煮至少一分钟的酱汁，以消除生淀粉的糊状味。	For best results, let pearl tapioca sit with the fruit for 5 to 10 minutes before you bake the pie so that the fruit juices can begin to soften the granules. And before you remove a pie from the oven, make sure the juices at the center are bubbling, even if it seems the juices at the edge have been fully cooked for quite a while.

发现马铃薯淀粉和箭头

Writing this article gave me an excuse to experiment with a couple starches that I hadn’t used much before, potato starch and arrowroot. They’re both wonderful thickeners, and I hope you’ll give them a try, too.

Potato starch is most commonly called for in European recipes. It’s easy to find in the baking ingredient aisle of East Coast markets, but in the rest of the country, look for it in the kosher section of the store. Potato starch thickens quickly without a pronounced flavor that needs to be cooked off, which makes it great as a lastminute fix for too-thin sauces.

Arrowroot powder comes from the root of a tropical plant of the same name. Look for it in gourmet or health-food stores. Arrowroot starch granules are very small and make sauces exceptionally smooth. Like flour and cornstarch, it can withstand long cooking and higher temperatures, and like tapioca, it is remarkable for its clarity. It’s a great choice for stir-fry sauces and any kind of fruit pie filling.

How to substitute one starch for another

当我开始研究淀粉实施指南时，我发现了从一本书到下一本书的许多不一致之处，以至于我决定进行自己的实验，这就是我发现的：

2 Tbs. flour = 1 Tbs. cornstarch = 1 Tbs. tapioca = 1 Tbs. + 1-1/2 tsp. arrowroot = 1-1/2 tsp. potato starch