Cheese Rheology Is a Branch of Physics

Cheese Rheology

Rheology is a branch of physics which revolves around the study of the deformation of the flow of matter. As one physicist explained, "Rheology is the study of the flow of materials that behave in an interesting or unusual manner. Oil and water flow in familiar, normal ways, whereas mayonnaise, peanut butter, chocolate, bread dough, and Silly Putty flow in complex and unusual ways. In rheology, we study the flows of unusual materials" (Morrison). For example, given the wide variety of the composition and structure of different varieties of cheese, from hard cheeses to soft cheeses, two different kinds of cheese are likely to have very different rheology.

The compressive vigor of a cheese is valued via the cheese's uniaxial compressive stress which is reached when a cheese fails during a compression test, with a uniaxial compressive load used. In a word: "large strain uniaxial compression indirectly measures shear behavior. Mohr's circle a construction widely used in the analysis of the strength of materials, enables the shear and compression stresses (up to the fracture point) and compression stresses (up to the fracture point) on an inclined plane at any angle… to be calculated" (Fox, 2004). This is an accepted way to measure normal and shear stresses when one is working with a sample of cheese that's undergoing uniaxial compression. It's not the only way, however, to measure these elements.

When it comes to the cheese at hand, Jarlsberg, its structure after analysis was as follows:

Fat

Protein

6.38 x TN

Moisture

NaCl

Milk Ash

L-lactic acid

D-lactic acid

TOTAL

28.8

27.7

38.9

1.3

2.3

0.0

0.5

99

This clearly indicates a cheese that has an overall moderate composition. It is neither to milky or too moist or too fatty or overly acidic, giving it a modest total of 99, just under 100. Thus, it comes as no surprise that Jarlsberg has a strain at fracture of 0.74. What's notable is that the one of other cheese that has a comparable level of strain at fracture is mozzarella cheese. This cheese has a 0.77 strain at fracture, remarkably close. This is particularly remarkable in that the structural breakdown of mozzarella in no way really resembles Jarlsberg. Mozzarella cheese has approximately one-third less amounts of fat, almost half the amount of protein, just a tiny amount of sodium chloride, and no D-lactic acid to speak of. However, it reaches a total analysis score that is notably close to Jarlsberg, reaching 100. This is because it has a moisture level of 63.7, practically double that of Jarlsberg. Obviously, this added amount of moisture allows has a profound effect upon the strain fracture and the general rheology of mozzarella. The added moistness allows it to mimic the rheology of Jarlsberg. Without this added moisture, one would have two extremely different cheeses with two extremely different rheologies.