Mother Cultures

Volume 132 No. 24 - Friday, December 14, 2007

It has been identified that the first factory for industrial production of cheese opened in Switzerland sometime in 1815. In the US, my research indicates credit goes to Jesse Williams, a dairy farmer from Rome, NY, who in 1851 started making cheese in “assembly-line fashion using the milk from neighboring farms.

Within decades, hundreds of such dairy associations and cooperatives began to spring up throughout the Northeast and northern Midwest. 
Today the US manufactures 25 percent of the world’s cheese in the most efficient means in the world.

What has made America great? We have a great desire to become the biggest, the best with little regards to the long-term outcome or consequences along the way. We tend to run through obstacles and have gratefully accepted our obstacles as mere opportunities towards greater success.

This is the same case for the cheese industry. The cheese culture market has followed the path of cheese developments in the US.
I cannot speak to the cheese industry in the 1800s or even to the industry up until the mid 1970s. However, with regards to the developments in starter technology, the greatest advances have occurred in the past 30 years. 

In the past 30 years we have seen mother culture grown in whole milk, multiple strain cocktail cultures grown in acid ripened bulk starter media, direct to the vat multiple strain frozen cultures (phase 1), defined single strain cultures grown in internal buffered bulk starter media, defined single strain cultures grown in external buffered starter media and finally direct to the vat defined strain frozen pelletized cultures (phase 2).

Having worked closely with cultures and cheese manufacturing technology over the past 30 years as a technical representative, marketing manager, product manager and sales representative, I can easily relate to overcoming the obstacles and opportunities as we have encountered them. 
Driven by economics, cheese manufacturing has put great demands on culture technology. In my next article, I will address the history of cheese culture economics.

Mother cultures and whole milk were the only option to early cheese manufacturing. Crude, by today’s standards, this process provided adequate but far from sustaining results. 

Originating from naturally occurring micro flora found in milk, a mother culture was “isolated” and carried by the cheese manufacturer. The mother culture was then transferred and grown in heat treated whole milk and ripened until an acid coagulum was achieved. 

The bulk culture was then agitated to break the coagulum and then cooled. This traditional bulk method of growing starter culture contained not only viable lactic acid cultures but some non-starter bacteria and a high level of cellular enzymes resulting from cell lysis or acid damaged cells during ripening. 

In a developing industry and many small cheese plants with small volumes, a wide range of quality, flavor and other attributes from the use of mother culture grown in whole milk could be observed. Cheese had a wide range of character from region to region. 

Generally, a mother culture and whole milk would require an inoculation of 1.5 percent per weight of cheese milk. This is important to note when I compare some simple economics of starter cultures to cheese manufacture.

With wide variation of cheese characteristics and with the consumption of cheese increasing there was a great push by cheese marketers and retailers in the US for more uniformity. As cheese consumption began increasing and demands for more consistency prevailed there was also a push for larger, more sophisticated cheese manufacturing facilities.

Two of the largest and oldest ingredient manufactures in the US, Chr. Hansen’s Labs and Marschall Dairy Labs (now Danisco USA), both originating as rennet manufactures, identified the need for providing cultures to the cheese industry. In the early 1960s both companies began the manufacture of mixed strain lactic acid bulk cultures. 

The service provided by both companies was to secure and isolate a seed stock of successful factory derived mother cultures and assure the quality of the stock and consistency. These “bulk set” cultures were primarily grown in whole milk but eventually introduced into a pre-tested, prepared bulk starter media.

Multiple strain cocktail cultures and acid ripened bulk starter media became growingly popular in the mid 1960s and early 1970s. The success brought by the consistency of the bulk set starter cultures opened the eyes of the cheese maker and soon saw improvement in control of their processes. 

However, as the cheese factories became larger, the incidence of bacteriophage within the operation became more prominent. Of course, this was not the fault of the bacteria strains but a result of the strain exposed to potential for bacteriophage infection over a longer manufacturing day. 

Bulk starter media was soon developed with different bacteria stimulants and phosphate salts, to chelate the dissolved calcium made available in the starter during ripening, to assure optimum culture health. Unfortunately, the formulation of these starter media would only stimulate the bacteria and protect from bacteriophage contamination within the starter tank. 

The media blends also assured the starter would be in optimum health going into the cheese milk. Bulk starter media was not only fortified with stimulants and buffering salts but was also pre-tested for activity and other quality aspects to remove some of the potential variables found when using whole milk as a growth medium. 

Original acid ripened bulk starter media was generally mixed at 11.5 percent solids. Typical inoculation levels were similar to the mother culture and whole milk, 1.5 percent per weight of cheese milk.

In the late 1970s to early 1980s cheese factories began to drastically reduce in numbers but began to become much larger. Driven by the need to be more economical and reduce the cost of cheese manufacture, the trend was to run more hours per day and more days per week. 

With this new pressure there was an increasing pressure on the lactic acid producing strains relative to rate of acid production as well as addressing the higher pressure or exposure to bacteriophage. By this time there were several players in the bulk starter media business. 

Anyone with a dry ingredient blender could manufacture starter media and they did it. It was different relative to the bacteria culture itself. 

Accepted as “free”, Lactococcus lactis and Lactococcus cremoris strains are naturally found in milk, began taking new perspective. What for centuries was taken for granted was now becoming a focal point for development. Starter cultures were finally being considered a critical ingredient and needed serious attention to meet growing industry demands for performance. 

Mother cultures, once recognized as “free” were in dire need of research and development to meet industry demands. While cheese ingredient suppliers used to sell or market starter media they began seeing the need to develop new technologies. It was this time in starter culture development that some major changes began to develop.

In our next column, we’ll look at how advances in starter culture technology have reduced costs to the cheese maker. 

Mike Comotto will be writing several articles on culture technology for Cheese Reporter. In addition to his many years of dairy ingredient representation, he has served as cheese judge and grader for a number of international, national and regional cheese contests. You can get in touch with Mike by e-mailing: columnists@cheesereporter.com.

The views expressed by Mr. Comotto and other columnists that appear in Cheese Reporter do not necessarily reflect those of the editor and Cheese Reporter Publishing Co. Inc.

Mike Comotto's Past Columns
Initial Thoughts

 

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