Swiss cheese and related cheese types with eyes include those manufactured in Switzerland (Emmentaler or Swiss), the Netherlands (Gouda and Edam), Italy (Fontina, Provolone and Asiago), Norway (Jarlsberg), Denmark (Havarti) and the United States (Brick, Swiss block and Baby Swiss) (Steffen et al., 1993). Swiss-type cheeses trace their origins to the Emmen valley in Switzerland. Emmentaler, the most popular Swiss cheese, is a large, round wheel, usually weighing about 100 kg (220 lb). Each wheel is about 112 cm (44 in.) in diameter and 15-23 cm (6-9 in.) thick, with a smooth, beige to yellowish rind. Emmentaler is simply called "Swiss cheese" in the United States and is a rindless block (Jenkins, 1996). The main characteristics of Swiss cheese are: (a) natural, attractive, uniform ivory to light yellow color (b) mild, pleasing, characteristic sweet hazelnut-like flavor (c) round or slightly oval-shaped eyes that are relatively uniform in size (1-2 cm [3/8-13/16 in.] in diameter) and distribution (d) uniform, firm, smooth texture and slightly elastic body In Swiss-style cheeses, eyes (CO2-formed openings) are expected and contribute to the cheese's visual appeal. The number, size, shape and surface luster of eyes are characteristic for each type of cheese. Extremes in Swiss cheese eyes appearance reflect adversely on workmanship and/or on milk quality. Normal eye formation results fromthe production of CO2 in the cheese, usually by propionic acid-forming bacteria and related types. In some Scandinavian-ripened cheeses, Leuconostoc mesenteroides ssp. cremoris and/or citrate-positive Lactococcus lactis ssp. lactis generate sufficient CO 2 to form characteristic small round eyes in the aforementioned cheeses. Gas holes in cheeses outside the Swiss-type category are generally considered undesirable because they often indicate the presence of undesirable lactic, spoilage and/or pathogenic microorganisms (Escherichia coli and Clostridia). Unintended gas formation in cheeses in the form of either CO 2, H2 and/or H2S is typically accompanied by an unclean-like off-flavor. Microorganisms used in the making of cheeses with eyes include: (1) Streptococcus thermophilus (produce lactic acid early in the cheese vat and the press), (2) Lactobacillus delbrueckii ssp. bulgaricus (produce lactic acid at a greater rate later in the pressing stage rather than in the vat) and (3) Lactobacillus helveticus (grow slowly and use up residual lactose and galactose-which is necessary to minimize browning and provide desired body and texture characteristics to cheese through proteolysis). Of particular importance is Propionibacterium freudenreichii ssp. shermanii, which plays a sequential role in development of a key flavor element, propionic acid, and the production of CO2, for characteristic eye formation. P. shermanii reproduce in the cheese, but not in the vat and require a temperature of >218C (708F). © 2009Springer-Verlag New York.
Cakir, E., & Clark, S. (2009). Swiss cheese and related products. In The Sensory Evaluation of Dairy Products (pp. 427–457). Springer US. https://doi.org/10.1007/978-0-387-77408-4_14