Q: What kind of walnut is best suited for baking?
Edwin, via e-mail

A: There are three basic walnut varieties.

English walnuts: Also called Persian walnuts, these are the most familiar type. Although native to Asia and Europe, California is now the major world producer. The shells of English walnuts are relatively easy to crack with a nutcracker, and the halves of the nut kernel can usually be removed in one piece.

Black walnuts: These walnuts have a very tough, dark outer hull, and the inner shells also are thicker than those of English walnuts. The shells have to be broken under so much pressure that the nut meats are usually crushed as well. These have a very distinctive, “cheesy” flavor. They are not to everyone's taste, but aficionados of these walnuts will go to great lengths to get their hands on them.

Butternuts: Also called “white walnuts,” these are native to the United States, but are rarely harvested for the marketplace. They are oilier and sweeter tasting than the other two walnut varieties.

As the English walnuts are easily available, I use these for all my bakery applications.

Q: I have two questions. Can the roots and leaves of rhubarb be consumed, and what can be used to sweeten the rhubarb stalks?
David, via e-mail

A: Rhubarb, which looks like a pink celery stalk, is botanically a vegetable, but it is used as a fruit, largely in pies and sauces. The roots and leaves aren't edible; in fact, the leaves are highly poisonous. Rhubarb stalks are extremely tart and require sweetening to make them appetizing. This can considerably increase their calorie content. For example, a typical home recipe for rhubarb pie calls for 4 cups of diced rhubarb to which 1 ¼ cups of sugar are added. This converts 104 calories' worth of rhubarb to more than 1,000 calories. An alternative to this is to sweeten rhubarb with other sweet fruits, such as apples.

Q: Our bakery ingredient supplier offers various types of cinnamon. Which one do you recommend using?
R.B., Davis, Calif.

A: Cinnamon is the dried inner bark of a tropical evergreen tree with about 100 different species, all with similar aromatic properties. The two most commonly available varieties are Ceylonese cinnamon and Chinese cinnamon. Chinese cinnamon, which is actually from the bark of the cassia tree, is not considered a true cinnamon. Grown in southern China and other parts of eastern Asia, cassia has a dark reddish color and is stronger in flavor than its Ceylonese cousin. Cassia is less expensive to process than true cinnamons and is the type of “cinnamon” most commonly sold and used in bakeries-though it is sometimes blended with Ceylonese cinnamon. Most cinnamon is sold in powdered form; however, it also is available in sticks (scrolled portions of bark) or essential oil. Cinnamon sticks are sold in various lengths, though the most common cinnamon stick is about 3 ins. long. My preference changes with my supplier or even the price, as the differences in outcome are very minimal and it has no impact on the application of use.

Q: How can we prepare cherries for freezing?
Dani, via e-mail

A: You can use several methods to pack cherries for freezing. The best one depends on how you want to use the frozen cherries later. I normally spread cherries in a single layer on sheet pan and freeze them. Then, I remove and quickly pack them in labeled freezer bags or containers removing as much air as possible. I seal and return them promptly to freezer. You can store them up to three months and use as needed.

Q: Throughout the week, we accumulate a few loaves of bread, which we use to make bread pudding. What can we do to set our bread pudding apart from the competition?
John, via e-mail

A: A whole world of opportunity exists with bread pudding, and it doesn't always have to be sweet. I like deep-frying (375°F) my bread pudding until golden brown, about three minutes. This gives the bread pudding a crispy outer crust, while maintaining a soft and moist internal structure and texture.

Q: Lately we have noticed a lot of published information on raisin products and would appreciate more information on raisin paste and juice concentrate. How can these products be used in a bakery?
J.S., El Paso, Texas

A: Extruding raisins through a fine mesh screen makes raisin paste. This paste can be used to add visual appeal and flavor to granola bars, yogurt, ice cream and other frozen novelties. It has excellent sweetening capabilities for use in fine confectionery fillings and bakery items, too. Raisin juice concentrate is a pure extract of raisins evaporated to produce self-preserving concentrate. It extends shelf life, substitutes for preservatives, maintains moisture and acts as a natural binding agent, enhancing flavors while sweetening and coloring food products.

Q: While reading the ingredient label of margarine, I wondered at the meaning of the E-numbers? Do you have an idea?
Michael, via e-mail

A: All food additives have E-numbers. The E stands for Europe. The E-numbers have been introduced in order to be able to clearly define the additives on an international level, because the names for the additives vary from country to country. Moreover, the E-number indicates the food additive is on the list of admissible additives, and therefore is not detrimental to health. Some examples are:

E 170 Acidulant calcium carbonate

E 263 Acidulant calcium acetate

E 300 Flour improver L-ascorbic acid (vitamin C)

E 322 Emulsifier lecithin

E 341 Acidulant calcium phosphate

E 410 Thickener carob gum

E 412 Thickener guar gum

E 450 Acidulant diphosphate

E 471 Emulsifier mono- and diglycerides of edible fatty acids

E 472e Emulsifier DATEM (diacetyl tartaric acid ester)