What is Swiss cheese?
The two most famous cheeses from Switzerland are Gruyère and Emmentaler, but it's the latter that has the distinctive holes Americans associate with Swiss cheese.
Emmentaler has been made for centuries in the Emme Valley, near Bern. Made from raw cow's milk, it must be aged at least four months and has a lovely, nutty flavor and great meltability.
However, most cheeses labeled "Swiss" in the United States are not made in Switzerland. They have Emmentaler's holes, and a similar flavor profile, but they might be domestic or imported from a country other than Switzerland.
Jarlsberg, for example, is made in Norway. According to Jarlsberg legend related on the website jarlsberg.com, Swiss cheese makers first brought their craft to Norway in the 1820s. In the 1950s, "a group of students and scientists at the Agricultural University of Norway decided to explore these cheese legends and combine them with modern cheese-making technology . . . and under the leadership of Professor Ole Martin Ystgaard they created a cheese with fine, round holes. The cheese was given the name Jarlsberg."
Jarlsberg is made from pasteurized part-skim milk, as is another ubiquitous Scandinavian, Finlandia. Some of those cheeses are made in Finland and Estonia, some are made in the United States. Kerrygold Swiss cheese, also part skim, is imported from Ireland. American-made "Swiss"-type cheeses include those made by Brewster Dairy in Ohio and Sargento in Wisconsin.
A true Swiss Emmentaler comes in a 200-pound wheel with the edge stamped "Switzerland" in red. Many of the lower- end Swiss-style cheeses come in oblong blocks to better fit on a meat slicer. That's what you get when you order a ham-and-Swiss sandwich at a deli.
I recently bought a whole slew of Swisses for a taste test: Two Swiss Emmentalers (one aged three months, another aged four months), Jarlsberg, Kerrygold and pre-sliced Sargento. No one much liked the Sargento, but the differences among the other four were small.
I preferred the Emmi classic. (Emmi is the brand of Swiss Emmentaler you're most likely to encounter at American cheese shops.)