I once read that "age doesn't matter, unless you're a cheese." This somewhat comical phrase is referring to the process of cheese production where various milks, depending on the type of cheese, are coagulated to concentrate specific proteins and fats that makeup the final dairy food product. Specifically it is saying that, like many wines, most cheeses improve in terms of flavor enhancement the longer they age.
An article by Greek authors Dimitra Dimitrelloua, Panagiotis Kandylis et al. asks if freeze dried kefir is a beneficial starter to use in this process of creating that perfectly aged cheese, specifically when making feta-type and whey-cheeses. Feta is one of the most popular food staples in a Greek food. Therefore it makes sense that these authors would want to determine the cheapest, most efficient, yet most flavor enhancing way to get this cheese production started.
To understand what is meant by this question and the results of their findings it would be great to first understand some of the science behind cheese making. Especially if one is considering home cheese making. In which case I would recommend the book, Home Cheese Making by Ricki Carroll, which is where I am getting most of my information on the process. To begin making any cheese, milk is needed and may come from a variety of mammals from cows to goats. Carroll raises the point that although milk may seem simple to us it is actually a complicated mixture of things – specifically water, a protein called casein, minerals, milk sugar or lactose, milk fat, vitamins and trace elements.
To transform milk to cheese the casein must curdle to form a curd, the raw form of cheese. After the curd is produced, it is processed to separate the hard part of it from its liquid whey component. This more condensed curd is basically the cheese we eat but depending on what bacteria are added to it later and how long they are allowed to treat it alter its flavor, texture, etc.
For the casein to curd in the first place, bacteria have to act upon the lactose and convert it into lactic acid. This process which separates the solid curd from the liquid whey is called proteolysis. Additionally rennet, a substance containing particular enzymes that speed up the process and therefore create curds sooner which can be strained from the remaining liquid elements of the milk. While some bacteria will naturally find their way to milk and can experience this reaction on their own, in today’s fast paced world it is much more common to use a mixture known as a starter.
A starter is a particular culture of bacteria that creates the ideal conditions, in terms of acidity factors to allow the rennet and bacteria to work together at a quick rate to separate the curds and whey. Originally, cheese makers would save some of their old cultures and save them in a tedious process to be used for the next cheese making batch. Now, many direct set starters are available for purchase that eliminate this process and let the cheese making process begin sooner. One example is freeze-dried kefir.
Kefir is similar to yogurt and is very inexpensive and has many health benefits. These benefits such as intestinal cleansing and immune system boosting can be seen at this Health Benefits Page from the Body Ecology store.Kefir is a substance that contains specific bacteria as well as rennet and therefore is a great combinational starter in the cheese making process. In addition to saving money and serving as an all-in-one add-on to the milk, the article concludes with the final decision that freeze-dried kefir significantly speeds up the ripening process and improves the "sensory characteristics" of both cheese types investigated.