Q. How can I produce a lemon-flavored yogurt similar to those one buys in the store.

A. There are two ways to give yogurt a lemon flavor. You can add lemon extract to the milk at the same time you add the culture (plain yogurt). Or you can make a lemon "sauce" to pour in the molds before adding the milk. The lemon sauce should be thickened with cornstarch rather than the pectin used commercially. Starch produces a gummier texture, but at least you can purchase cornstarch, whereas the pectin they are using is not the same as the Sure-Jell or Certo available in the store.

Here's a recipe for lemon yogurt sauce: LEMON YOGURT SAUCE (Enough for 1 quart of yogurt)

* Peel of 1 lemon (yellow part only)

1/2 cup lemon juice, freshly pressed

1 tablespoon sugar or honey

1 tablespoon cornstarch

1/4 cup cold water

1/4 drop yellow food color (optional)

Using a swivel-bladed potato peeler, remove the peel of 1 lemon. Juice approximately 4 lemons to obtain 1/2 cup of juice. Add sweetening. Bring to a boil. Stir cornstarch into cold water and add to the lemon juice as it just comes to a boil. Reduce to low heat, cook and stir about 2 minutes. Add the food color, divide among your yogurt containers and allow to cool. The lemon sauce should become quite thick. That way, it won't mix with the milk as it ferments. Add the cooled and inoculated milk and proceed as you would with any other flavor of yogurt.

Q. How important is beer to the success of a beer batter used to coat fried vegetables and fish? Also, does the beer's yeast begin to ferment the batter? How do you prevent lumps in the batter? How important is it to fold beaten egg white into the batter at the end?

A. You could replace beer with milk and not really taste the difference after frying, although milk will make the batter a little sweeter. An active component of beer and milk is water: The flour's proteins absorb it and produce a viscous batter. The second active component is carbon dioxide gas: it helps leaven the batter, although the beaten egg whites do a fine job of that if you fold them in carefully.

Bottled beer is usually pasteurized; otherwise the beer turns cloudy and develops "off" flavors. The few remaining yeast cells are therefore dead and cannot ferment.

To prevent lumps in a beer batter, make a well in the middle of the dry ingredients, place the whole eggs or egg yolks in the center, pour in oil or melted butter if specified and, using a whisk (never a spoon), stir the liquid ingredients while slowly adding the beer. When all the flour has been incorporated and you have a thick paste, whisk it vigrously, then add the remaining beer. Let the batter sit at least 30 minutes before folding in the egg whites.

Egg whites give the batter a little more airiness. They are not required, however. In fact, they cause the batter to absorb far more oil while it is frying because of the coating's increased porosity. To incorporate an egg white foam, first beat the egg whites with a fine-wire whisk until they form an almost firm foam. Whisk one-third of the foam into the batter; fold in the remainder.