11/23/2007

Water and Salt - Caviar Taste

Does it matter where the fish come from the make your caviar? Of course. Caviar from clean water, free from pollution tastes cleaner and makes you feel better. Like taking vitamins, the net health effect may not be immediately detectable, but we certainly enjoy our caviar more knowing it is from clean, cool water. The same can be said for Maine lobster.

Rumor has it the cold water produces a harder shell and sweeter taste. It took me about 5 or 6 years of eating lobster every year in Maine to begin to recognize a difference. While I've never eaten a lobster I did not enjoy, I am beginning to prefer the Maine variety.

From great waters stem great food traditions: like Maine Lobster, or Nantucket Bay Scallops, or wild Alaskan King Salmon and Colossal King Crab legs. For caviar, we find fish growing in cold, clean water produce a more pure tasting product.

Pictured above is the Tennessee River below the Great Smoky Mountains. Hackleback American sturgeon and paddlefish are caught in this river. Surprising beauty from a part of the country I had not visited before working with caviar. We often find very clean water sources in rivers and springs throughout the United States, not just in the far northern waters of Maine and Alaska.

TEMPERATURE—Water Temperature can impact the flavor of fish. For example, some farmed caviar picks up an off-flavor when it is grown in warm water. The warm water in re-circulating tanks can accumulate algae. It is a common problem in aquaculture that algae can produce an off-flavor. This might taste like a muddy or pondy taste. We see it more often in caviar from California, where water temperature can approach the high 70's F, and less in somewhere like Idaho where temperatures are closer to 80 F and there is no re-circulation. However, some farms in CA will send their fish to the cleaner waters of Tahoe to simulate the fish’s natural run upstream. This also serves to reduce the harmless but undesirable algae flavor.

Water temperature also determines the month of harvest. The water is cold enough in Idaho to make caviar year-round, which is an absolutely amazing concept. Everywhere else in the world caviar is seasonally produced, with salts providing the preservative to help it last until the holidays.

Cold water also makes fish grow slower. It often takes 2-4 more years to grow sturgeon in Idaho than California. Due to its long growing season, Sacramento, California seemed like an ideal location to grow sturgeon in the 1980's when that industry started with the help of the University of California Davis. While the growing season spans 7-9 months, there are times when the quality of caviar can change from this seasonality, and for this reason we do not sell much caviar from California, though we enjoy eating it when it's fresh.

There is some wonderful caviar from California, and very large quantities are produced there. We may find in the future that other locations produce a higher proportion of superb caviar year-round, without problems from algae or seasonal harvests. Regardless, this region has really helped to propel farmed caviar onto the world stage.

There are some rumors that caviar tastes more salty when the fish are raised in freshwater. We have not found this to be the case. Freshwater fish do hold a higher proportion of ions in their blood than saltwater fish do, but that does not affect the taste of the fish. Pike, trout and sturgeon are very mild fish, not salty tasting. The fish commonly producing caviar are often migrating from saltwater to freshwater and are often harvested after entering freshwater. At that time, the fish have already adjusted to freshwater, just as a fish would be had it spent its life in a freshwater river.

The biology varies a lot among different caviar fish species. What does not vary, however, is the salt content of the caviar. Manufacturers set the salt percentage based on the amount of final salt they want in their product. Salt acts as a preservative, and is often set around 4 percent. Subtle differences in saltiness of the fish are not perceptible, though adding different quantities of salt are. 3.5% tastes very good, 2% often taste bland, and 6% tastes very salty. The FDA standard depends on the final salt percentage, not on how salty the unprocessed roe is.

Not all salts are created equal. For example, the most common salt used is NaCl, or table salt. Not surprisingly, table salt is a "salty" tasting salt. Meaning, table salt tastes like salt—what we think of as salty. Other salts, however, taste bitter, savory, and sweet. Potassium chloride, very effective at lowering blood pressure, tastes bitter. Potassium is often used in low sodium foods, and the end product tastes less salty than is the same amount of table salt was used. MSG was actually created for its flavor -- it's a savory salt. Sea Salt is a blend of many salt ions that produce a balanced saltiness I think is less salty than table salt, and slightly savory. Borax is a sweet salt, and a microbial preservative.

Borax is a naturally occurring salt found in the mud of the Caspian Sea. Centuries ago, caviar was packed in cloth and stored in the cool mud of the Caspian before transportation to Europe. The borax leached in and acted as a preservative. Today, borax is still used in much of the caviar produced outside of the U.S. American manufacturers are not allowed to add borax, because it is a type E carcinogen and its antimicrobial effects can mask the deterioration of expired product. Likely, borax will not hurt you, but it is what it is. Other preservatives not used in the U.S. caviar include Nisin, Sodium Nitrate and Sodium Nitrite. I don’t know of U.S. manufacturers using preservatives, but we’ve tasted some edible results with mild fruit acids like vitamin C, citric acid, and some sorbates.

One hypothesis I have is that caviar from the Caspian tastes less salty because it contains borax, not because it is produced from saltwater fish. The preservative aspect of borax allows manufacturers to use less salt, and the sweetness masks the flavor of salt. As much as I do not like the idea of eating caviar salted with borax, some of the best caviar I have had has come from Iran and Russia, which almost certainly used it or some other preservative. 100 years ago the U.S. caviar market was booming in the Hudson and Delaware, and before that the rivers of Europe. To my knowledge, none of the manufacturers used borax and no one missed it. Still, many connoisseurs miss the sweetness when it is absent.

In the future, we will likely see more farmed caviar from the U.S., Latin America, China, Israel, and Europe. I believe the world's finest caviar has yet to be tasted. And, if global re-stocking and farming efforts continue, the best caviar may come from wild sustainable fisheries. Had no hatchery programs existed in the Caspian and Black Seas, sturgeon may already have gone extinct.