Burning questions: On the color of salmon

Why is Atlantic salmon a paler color than Pacific salmon?

Hey, you're lucky Atlantic salmon even has a color.

Before we get to the hue of their flesh, let's review the differences between Atlantic and Pacific salmon. Wild salmon is caught off the Pacific coast of the United States and Canada from spring through fall in scores of individual "runs." Each run refers to the time that one of six species of salmon -- chum, coho, king (chinook), pink, sockeye and steelhead -- returns from the ocean to its river of origin to spawn, or lay eggs. Fishermen catch the salmon in the ocean just before they head upstream.

In the ocean, wild Pacific salmon eat, among other things, krill, tiny shrimplike creatures. Like shrimp, krill contain astaxanthin, a red pigment that lends wild salmon a vivid color that ranges from bright orange to deep red.

There is some salmon farming (aquaculture) on the West Coast, but for the most part, Pacific salmon are wild. Atlantic salmon, on the other hand, are almost entirely farmed. Whether you are buying salmon from Canada or Norway or Scotland or Ireland, it has been raised in captivity and is a species distinct from those in the Pacific. A farmed salmon eats a processed diet of fish meal along with some distinctly nonaquatic ingredients such as wheat and soy.

Because farmed salmon do not eat krill, their flesh would naturally be a pale shade of beige-gray. To avoid this unappetizing color, salmon farmers add synthetic astaxanthin to their diets. I suppose if they added more astaxanthin, they could make the salmon flesh even brighter. But they also might wind up making it look like a traffic cone.

What makes wine kosher, and what makes kosher wine kosher for Passover?

Kosher wine comes from exactly the same source as nonkosher wine: grapes. It's how the grapes are handled that determines whether the wine is kosher. The Bible sets out rules for the growing of grapes and the making of wine that include:

All winemaking equipment must be kosher, maintained as kosher and used exclusively for kosher wine.

All the ingredients used in the production of the wines must be kosher. (Clarifying agents made from eggs or gelatin, a meat product, are verboten; instead, a mineral clarifier is used.)

From the moment the grapes reach the winery, only Sabbath-observant Jews are permitted to come in contact with the wine.

If a kosher winery wants to make kosher-for-Passover wine, it must undergo a thorough cleaning process to remove any chametz (leavened-bread products) on the premises -- just as kitchens and other food-manufacturing facilities must do.

"Mevushal" is a term used to connote a kosher wine that has been pasteurized. In Biblical times, wine was a key element in the religious rites not only of Jews, but of their pagan neighbors. A practice arose among Jews to boil their wine in order to distinguish it from that of the pagans. Over the millennia, this evolved into a tradition whereby boiled wine was considered to retain its kosher status, even when handled by non-Jews, in a restaurant or at a catered affair, for example. Nowadays, mevushal wines are flash-pasteurized rather than boiled to minimally affect their quality.