I've had enough of horse racing and linguistics anyway. So what is malt, then? And why do so many bagel and other bread recipes call for it? In fact malt isn't so much a thing as it is a process. "Malting" is a word that means the same thing as "sprouting", or perhaps more precisely, "germinating". It happens when a seed, notably a grain like barley, is exposed to water and a temperature of around 65 degrees Fahrenheit. The seed, which is composed of an embryo (the germ) and a food supply (the endosperm) begins to grow. Which is to say the embryo begins to send out a shoot, at which point various enzymes in the seed switch on and begin slicing the long-chain starch molecules in the endosperm down into simple sugars the embryo needs to fuel its growth. Typically these enzymes produce sugars faster than the shoot can consume them, giving us humans a big opportunity.

On the one hand, one may simply dry malted barley (stopping the malting process but without deactivating the enzymes) and then grind it into powder. The result is so-called diastatic malt powder, a grain-sugar mixture that still has active enzymes in it, enzymes which are capable of breaking down starch when they're mixed with water (the word "diastatic" comes from the Greek diistanai, which means "to separate"). Diastatic malt is useful for baking types since it boosts the sugar content of bread (both by itself and as a result of the action of enzymes), enhancing taste and darkening crust (which occurs as a result of caramelization). Almost impossible to find in stores, diastatic malt usually has to be custom-ordered.

If one were to dry the malted barley and then toast it (which destroys the active enzymes but creates a nice yummy flavor), the result is non-diastatic malt powder. This is the stuff that's usually combined with sugar and dry milk to make malted milk powder. People add it to chocolate shakes to make "malteds", mix it with cocoa powder and sugar and form it into balls, or simply add it to hot water and/or milk and drink it.

If one were to dry the malted barley, then toast it, then mash it to goo and cook it, the result would be malt syrup (at least after it was filtered). Malt syrup is a sticky molasses-like liquid that you can find in health food stores under the name "barley malt". Healthy food types use it as a "natural" sweetener, though there's really nothing any more "natural" about malt syrup as compared more conventional syrups, it's just composed of different kinds of naturally occurring sugars (mostly maltose and glucose). It's about half as sweet tasting as sugar, though it has every bit as many calories.

Bakers use malt syrup for the same reasons they employ diastatic malt, to enhance flavor and color, but of course without adding active enzymes to their dough, which depending on the recipe, might not be either welcome or necessary.