How often have you beaten egg whites for a recipe? Soufflés, meringues, angel food cakes, and chiffon pies all depend on airy whites for their loft. And what about whipping cream? Not only is it the secret to ethereally light mousse (such asRaspberry & Blackberry Mousse）但是，鲜奶油也非常适合分层放入草莓酥饼，顶馅饼或装饰简单的冰淇淋圣代。

当你打蛋清或奶油和液体基本脉冲电平lows into an airy mass, a similar transformation seems to occur in each. But plumes of whipped egg white and cream have less in common than you might think. They are alike in one important way, however: They’re both foams. Like soapsuds and the head on beer, beaten egg whites and whipped cream trap air in a soft network of stable bubbles.

Protein and fat stabilize bubbles

When you blow air through a straw into a glass of water, bubbles form and quickly disappear. But when you whisk air into egg whites or cream, bubbles form—and linger—because the proteins present in these viscous liquids stretch around bubbles and trap them.

Here’s where the foams differ: In whipped egg whites, proteins alone do all the bubble building. In whipped cream, proteins share the task with another substance—fat. This important distinction influences how cooks use beaten egg whites and whipped cream in recipes, so let’s take a closer look at how each forms.

蛋清捕获水和蛋白质网中的气泡。蛋清是蛋白质（10％）和水的混合物。跳动的作用会产生气泡，同时哄骗盘绕的蛋清蛋白将其解开并重新组合成柔软的网状薄片，这些薄片包裹着气泡。随着持续的鞭打，气泡变小，泡沫变厚成稳定的质量。

Fat: friend or foe?Whipped egg whites can billow up to eight times their original volume. But a drop of yolk or a little grease lingering in a mixing bowl can reduce the egg whites’ foaming power by two-thirds. That’s because the fat bonds with the egg proteins before they can bond with one another and form those mesh-like protein sheets necessary for trapping bubbles.

虽然最细微的脂肪是鲜蛋白的衰落，但在鲜奶油中，固体奶油效果与牛奶蛋白一起搭建泡沫。鞭打冷奶油不仅将牛奶蛋白订购到薄膜中以进行气泡建筑，而且还会导致固体黄油的显微镜簇，这些脂肪片被悬浮在冷液体中，以包围和稳定每个气泡。但是，如果黄油脂肪变暖并融化，泡沫将崩溃。

泡沫很挑剔

Egg whites whip to their greatest volume at about 70°F. When whites are warm, they don’t cling together as much, making it easier to incorporate air. Cream, on the other hand, whips best when the cream, the bowl, and the whisk are very cold (45°F or lower) and the butterfat is solid.

当涉及到鞭打鸡蛋时，专业意见有所不同。随着鸡蛋的年龄，白人变得更薄，很容易鞭打成大量的体积。新鲜的鸡蛋更具粘性，因此需要更长的时间才能打败，但是有些厨师认为由此产生的泡沫更稳定。特别是为了制作蛋白甜饼云，我们选择了较旧的白色和额外的体积，并添加一点牙垢奶油来稳定泡沫。使用奶油，不会影响蓬松度和稳定性，而是脂肪含量和温度。奶油和更多的脂肪会使泡沫变得更硬，更稳定。浓奶油，脂肪为36％至40％，鞭打成坚硬，稳定的泡沫；以30％至36％的脂肪搅打奶油，使泡沫更柔软，稳定。

How long to beat?

蛋奶酥和海绵蛋糕的食谱通常会说要鞭打蛋清，直到抚摸搅拌器时柔软的峰值卷曲。在此阶段，白人保持灵活，因此它们很容易与其他成分混合。但更重要的是，气泡仍然足够弹性，可以在烤箱中膨胀。这使蛋奶酥蛋白蛋白凝结并放在烤箱的热量之前，蛋奶酥的框架可以更高。

对于像慕斯这样的冷藏或冷冻甜点，在添加了鸡蛋白泡沫之后不会进一步烹饪，从而产生了强烈的泡沫（与足够灵活的泡沫相反，可以在烤箱中进一步膨胀）。因此，将白人打到僵硬（但不干燥）阶段。在此阶段，泡沫包含更多的小气泡，数量有强度。

Use ’em or lose ’em.您是否曾经击败过白色以完美的中型山峰，转过一会儿以测量其他成分，然后返回到您的泡沫外观干燥，结块和过度becte脚的泡沫？那是因为暴露在空气中的卵白泡沫迅速开始凝结并失去其弹性。因此，如果您将蛋清打成蛋白，而无需糖或蛋奶酥，请确保将所有剩余的成分准备就绪，并在殴打白色后立即加入它们。

Overbeating makes foams flop。跳动使泡沫扩大，但不能无限期进行。如果蛋清被鞭打过长，则泡沫会变干，块状且过于脆，无法支撑蛋奶酥。OverBeaten Cream提出了另一个问题，因为它分成凝乳（黄油）和乳清（酪乳）。

现在您知道了泡沫的工作原理，舞台是为您制作过的最矮的souffl olfte和最轻的慕斯。

	Egg whites	Cream
Temperature	about 70°F (to warm eggs, soak them in warm water for 10 minutes)	越好，越好，33°至45°F越好
体积	increase 6 to 8 times	增加2至3次
How to hold	不建议	refrigerate, covered, in a cheesecloth-lined strainer, for up to 3 hours
Signs of overbeating	appear dry and lumpy; liquid separates out; hard to blend with other ingredients	no gloss, looks grainy and curdled