Wiki: Body Defects, Mechanical Holes

Body mechanical holes defects of cheese are normally associated with rennet coagulated pressed cheeses can appear in other cheese types. Some cheeses (like Swiss) intentionally develop fairly evenly spaced round-spherical holes commonly called eyes. Most unwanted mechanical openings are irregular shaped and randomly distributed. This article is not for intentional eyes but for unwanted mechanical openings and includes a description and causes and solutions organized by root cause.

Description

  • Body of cheese has unwanted irregular shaped and randomly distributed mechanical holes. These may shrink or disappear if a cheese is partially dehydrated during aging as the cheese shrinks in size.

Yeast Contamination

Swollen and barrel shapped yeast contaminated Cheddar.
Swollen and barrel shapped yeast contaminated Cheddar.

Cause

  • Yeast contamination of curds during cheese making phase causing the production of carbon dioxide gas within the cheese resulting in yeasty smell, unwanted holes, cheese feeling “spongey”, and in extreme cases the cheese swelling significantly. While the resultant cheese may be edible, it will generally have unwanted texture or flavour.

Solution

  • There is no solution for current batch of cheese.
  • The solution for future cheese making is better sanitation, remove sources of yeast (do not make bread at same time as making curds and forming cheese).

Coloform Contamination

Cause

  • Coliform is a bacteria found in feces that has contaminated the milk and thus the cheese curd. It normally results in random somewhat roundish holes in the cheese body (such as from uneven pressing) and in a bad sourish smell.

Solution

  • There is no solution for current batch of cheese.
  • The solution for future cheese making is better sanitation.

BAB Contamination

  • ‘Late Blowing’ or excessive eye formation is a defect caused by the growth of butyric acid bacteria (BAB), mainly Clostridium tyrobutyricum, normally after 4-6 weeks of ripening. The defect can vary from slight gas formation and slightly larger eyes than normal with almost no perceivable off-taste, to very intensive gas production resulting in a higher number of large eyes, cheeses torn open and a clearly perceivable taste of butyric acid.
  • Brine-salted cheeses such as washed curd cheeses are particularly sensitive to `late blowing’ due to the time it takes the salt to diffuse from the exterior to the middle and resulting in a sufficiently high salt concentration to inhibit germination of Cl. tyrobutyricum spores.

Poor Pressing

Natural rind 4 pound Gouda inadequatly pressed resulting in mechanical holes.
Natural rind 4 pound Gouda inadequatly pressed resulting in mechanical holes.

Cause

  • During pressing stage of cheese making, temperature was too high or pressure was too low or time was too short resulting in poor removal of holes between curds. Normally occurs on harder curd cheeses.

Solution

  • Press at temperature or pressure or duration as per recipe/method for cheese type.