By Catharine L. Kaufman
As autumn approaches, some of us shift gears full throttle into baking mode. The aromas of sweet fall spices (cinnamon, nutmeg, cloves and cardamom) perfume the home as apple pies and fig tarts, banana and zucchini breads, and pumpkin and cranberry muffins envelope the kitchen in culinary bliss.
Some readers want to know how to become savvy bakers. I'll now take your questions.
Q: Are baking soda and baking powder interchangeable?
A: Although baking powder and baking soda are both leavening agents used to make baked goods rise by producing bubbles of carbon dioxide, they react differently in a chemical sense with other ingredients, so they can't always be substituted.
Baking soda is pristine sodium bicarbonate. When it combines with other ingredients like milk or eggs, the chemical reaction is immediate. Recipes need to be baked pronto or the leavening effect will be kiboshed, and the finished product will be pancake-flat.
Baking powder, on the other hand, is a blend of sodium bicarbonate, cream of tartar and usually starch. There are two versions: single-acting and double-acting.
The former, which is activated by moisture, requires the recipes to be baked immediately, while the latter has some forgiveness and the mixture can stand before baking.
Since baking soda is a pure base, it needs to combine with an acid such as buttermilk to counteract the bitter taste. Baking powder is both a base and an acid, yielding a neutral taste. It is usually used in recipes with other neutral-tasting ingredients such as milk.
While baking powder can be substituted for baking soda (although you will have to add more), you cannot switch baking soda for baking powder. Homemade baking powder can be easily concocted by combining two parts of cream of tartar with one part of baking soda.
One last recommendation: Purists buy aluminum-free baking powder.
Q: How do you prevent brown sugar from clumping or hardening?
A: Since exposure to air hardens brown sugar, it should be properly stored in an airtight container — whether a canister, can or moisture-proof plastic bag stored in a cool, moist area. The sugar should not be refrigerated, but it can be frozen.
And although brown sugar has a long shelf life, it should be used within six months of purchase to maintain its integrity in terms of flavor and texture.
If the sugar loses its natural moisture and hardens, there are two modes of damage control: Heat the sugar in a 250-degree oven or microwave until it softens, and use immediately as it will harden quickly. (Caution: Heated sugar is scalding hot, so be careful when handling.)
Or try the snail-paced approach, which takes about two days. Place the sugar in a rustproof container covered with plastic wrap and a damp napkin or paper towel. Tightly cover, and remove the sugar after it has absorbed the moisture and softened. Reseal in an airtight container.
Q: Is there a difference between dry and liquid measuring cups?
A: In this country, ingredients are measured by volume, while other parts use more accurate weight measures.