In the past, farmers went through a lot in the guise to keep fresh milk safe from spoilage, and to do this, they came up with one solution which was Cheese. Say cheese to the camera, and as you say so, let me use the opportunity to wish you a happy new year.
In other to get cheese, the perishable milk had to be turned into something that could be stored for months, and this was done via fermentation with microbes. They just needed to acidify bacteria and enzymes to cause milk protein and fat to form clumps which are the starting point of cheese known as Curds. With just a simple process of fermentation, there are over 2000 ways to make cheese giving over 2000 types.
Talking about types of cheese, the mature cheddar undergoes month of bacteria action where the starter bacteria gets all the required energy by breaking down lactose into lactic acid and this clump the milk protein casein into curds which are stacked on one another in a cool, dark place after being shaped into blocks to release the whey which is the liquid leftover which is the process known as cheddaring. As the cheese get older, starter bacteria die off while new bacteria starts to grow and continue the fermentation process changing molecular structures and this bacteria can either find their way to the cheese from the air around or they can be added by the cheese maker.
In this process, it is a win-win for all of us as the microbes get energy that way while we get fhe cheese we need and the flavors they leave behind include alcohol, esters, and acids which will remain in the cheese until it is cooked or consumed.
Remember i mentioned whey before and i mentioned that it is liquid. It is a mixture of water, non-casein protein, and fats that didn’t curd, and cheese makers just needed to do something with it and they found a way to use it to make more cheese. They do so by just recooking it which is were the name of the cheese Ricotta is gotten. Because of the stability of the Non-cassein protein in curds, it is cooked so the temperature is increased, also more enzymes and bacteria are added to it.
Still on cheeses, there are some cheeses that have holes in them like the Emmentaler and to get this type of cheese, the bacteria P.shermanni is used to break down the lactic acid into other molecules and carbon dioxide gas where it bubbles to become holes or eyes the more it stays longer. Since cheeses are made from bacteria, it means that improperly made cheeses can leave people with infections associated with the bacteria including listeria bacteria infections which comes with symptoms including digestive problems, fever, and muscle ache. As a cheese maker, it is advisable to use pasteurized milk which would have killed the bacteria through heat.
Let’s say you have seen cheeses with vein lines of color green and blue. These type of cheese are made not from bacteria but from fungi such ad pennicillium mold. A cheese made from this is the Gorgonzola and aside from the blue veins that we see, the molds release free fatty acids, ammonia, and ketones. It might look there these cheeses are getting prepared by different microbes and little changes in procedures but they all follow the same process of fermentation.
Reference
https://global.oup.com/academic/product/the-science-of-cheese
https://www.journalofdairyscience.org/article/S0022-0302(13)00371-8/fulltext
http://onlinelibrary.wiley.com/doi/10.1002/jssc.200500400/epdf
https://pmc.ncbi.nlm.nih.gov/articles/PMC9150401/
https://www.cdc.gov/listeria/causes/dairy.html
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2843518
https://www.sciencedirect.com/topics/agricultural-and-biological-sciences
https://www.acs.org/education/chemmatters/past-issues/2017-2018
https://pmc.ncbi.nlm.nih.gov/articles/PMC7142753/
