Tag Archives: diffusion

Leavening in the Kitchen: Incorporating Air

In the introduction to leavening, we discussed how gases in our batters and doughs expand to add volume and tenderness to our baked goods. Over the next few posts, we’ll explore how those gases get there in the first place. Today, we’re talking about air, which is the foundation of all leavening. It’s easy to see air’s role in meringues and sponge cakes, where it’s beaten in for volume and fluffiness. But air is crucial to the success of other leaveners like baking soda, steam, and yeast. In this post, we’ll explore what air is, how we use it, and how it behaves in the kitchen.

Red Bean Dessert Soup (紅豆湯)

Red bean soup (紅豆湯,) is a popular dessert throughout China, Taiwan, and Hong Kong. It’s made from red beans (紅豆, also called adzuki beans) which are incorporated into many East Asian desserts. Red bean soup itself is versatile. It can be eaten hot or cold, plain or with toppings, liquid or frozen. When my mom first dictated her version to me, she cautioned, “糖最後加，不然紅豆煮不爛！Don’t add the sugar until the end, else the beans will never soften!” Today, I’m sharing my mom’s recipe, adapted for a typical Western kitchen and pantry, then discussing the science behind her words.

Apple Pie

In the last post, we discussed how sugar preserves the structure of cooked fruit. This comes in handy for fruit pie fillings, which often become a mushy and wet (but nevertheless delicious) mess. In this recipe, apples are tossed with sugar and drained. The drained liquid is cooked into a thick syrup that’s added back to the apples and baked. The apples maintain some crunch, not much water leaks into the pie, and the syrup adds an extra punch of flavor. Let’s take a look at the recipe and then discuss the science!

Sugar in the Kitchen: Special Applications

Over the last few posts, we discussed a lot of sugar’s roles in baked goods. It’s important for flavor, texture, structure, and color in cookies, cakes, and muffins. But sugar’s roles in baking extend further. Sugar is important in meringues as a stabilizer, in yeast breads as a source of energy for the microorganisms, and in fruit desserts to preserve the structure and texture of the fruit. In this post, we’ll explore sugar’s myriad roles in these sweets.