Starter Culture Development

Volume 132 No. 28 - Friday, January 11, 2008

Following sabbaticals of Dr. Gary Richardson, Utah State University, and Dr. Bill Sandine, Oregon State University, to New Zealand, interest began to materialize in using defined single strain cultures. 

During the same time, two major developments began to change the manufacture of bulk starter media. One bulk starter media development came out of academia, the other from industry. 

It was the mid 1970s when Dr. Gary Richardson began working with external pH controlled bulk starter and defined single strain cheese cultures. 

It was also this time that Dr. George Weber of Galloway West (now DSM Food Specialties) initiated the concept of internal pH buffered bulk starter media. Galloway West brought the concept to Oregon State University for development and funded the ensuing research. Both of these developments were major turning points in bulk starter technology.

While these two concepts were being developed, Chr. Hansen’s and Marschall Dairy Products (Danisco USA) were making major investments in the first phase of direct to the vat cheese cultures. The development of highly concentrated cultures required major investments for equipment and manufacturing facilities, and a complete philosophy change on how to approach the cheese industry in sales and marketing was developed. 

While direct to the vat cheese cultures provided ease of use, flexibility, reduced labor cost to the manufacture and some other reduced cost to manufacture bulk starter, the two major drawbacks were the cost compared to other culture alternatives and the fact they required about one hour longer make times because the culture had to thaw, repair their cell wall, become acclimated to the cheese milk and begin to produce acid; basically, required more ripening time. 

The convenience factor and the flexibility to switch strains at any given time really favored the direct to the vat cultures. Although this was also a time when factories were expanding at an alarming rate, make times were being compressed and a 30-40 minute ripening time was difficult to fit into the make schedule. After all, when becoming time efficient, time equals money. The first run of direct to the vat cultures had 4-5 years of glory but soon became a mere convenient back-up program to the internal and external pH controlled bulk starter programs.

pH-Controlled Bulk Starter
pH controlled bulk starter programs featuring defined single strain cultures grew in favor by the cheese manufacturer by 1985. Every efficiency presented to a cheese factory that would improve growth to the bottom line direct cost and consistency were easily marketed and sold. 

Consider the fact that pH controlled bulk starter programs substantially cut cost of conventional bulk acid ripened media systems and provided a healthier and higher cell concentration. Add the bonus of defined single strain cultures, bacteriophage could be easily monitored, you had a program that fit into the expanding cheese plants’ plan for growth, efficiency and consistency.

The cost savings of pH controlled bulk starter media were recognized in several areas. First, the acid ripened media are generally mixed at 11.5 percent solids. pH controlled media are mixed between 5.8-7 percent solids media. 

The original concept of external pH control bulk starter systems, developed by Dr. Richardson, actually used the plant’s own whey source with a small amount of stimulants and buffering salts to produce the finished starter. I had the opportunity to work in one of the original factories utilizing this technology, Ward’s Cheese, Richfield, ID. 

Anhydrous ammonia was used to neutralize the acid in the bulk starter during fermentation. The gaseous ammonia would be released into the starter, forming ammonium hydroxide and neutralizing the lactic acid forming ammonium lactate and water. The fermentation would be dictated by lactose content. 

When using the plant’s own whey, two problems were encountered; first, quality of the raw whey would vary; and second, the potential of bacteriophage introduced into the starter room could be devastating. 

Actually, the second problem was the resulting issue at Ward’s Cheese. However, they did convert to a pre-tested complete media and soon improved their process.

Once the pH controlled bulk starter is ripened the amount of culture added to the cheese vat is typically 0.7-0.8 percent. The reason for the 50 percent reduction of pH controlled versus acid ripened culture was because there is a higher concentration of healthy cells and the growth environment is always maintained within a favorable range.

With all of the advances in pH controlled bulk starter and defined single strain cultures the cost to the cheese maker was drastically reduced. So much that the cheese factories that had converted to direct to the vat cheese cultures could easily justify a new bulk starter culture room with as little as a six-month payback. And convert they did.

Two small start-up companies, Biolac, Inc. and Nordica International, Inc. challenged the big ingredient suppliers with their introduction of defined single strain cultures and pH controlled bulk starter media systems. I had the opportunity to go to work for Nordica International. 

The success was great with little time to rest. In hindsight, the reason for the busy schedule in converting cheese plants to the new technology was probably due to the fact that we were not charging enough for the technology provided to the end user. 

However, the new wave of technology did prevail and within a few years of growth and success both Biolac, Inc. and Nordica International, Inc. were acquired by other companies. 

The cheese manufacturer benefited with both a lower cost bulk starter system and more consistency. The cost of starter was becoming the least cost ingredient in converting milk into cheese. 

This was very good news to the cheese plant from a cost standpoint but not good when considering the big picture. The big picture, how can the ingredient manufacturer invest in research and development in a market shrinking in sales to the tune of 50-75 percent?
Investing in R&D

While the average pay price for milk has been steadily increasing in price since 1975 we have seen the direct opposite happening in the price of the most crucial ingredient in the cheese manufacturing process.

In the 40 or so years of commercialization of starter cultures in the US, pH controlled bulk starter has dominated in its brief existence. Huge developments and efficiencies have occurred to benefit the cheese maker. As technology has increased the value of the bulk starter market has decreased nearly three-fold relative to milk price.

It amazes me that the ingredient suppliers continue to push research dollars into the shrinking cheese culture market. But, the new research dollars are being marked to develop the second phase of direct to the vat cultures. 

About six years ago Chr. Hansen began to market a direct to the vat culture program. Several other ingredient suppliers are following the success of the new technology. 

I will review some of these successes and include how the technology will possibly change the US cheese market in a future article.

I said earlier that I would address economics of the cheese culture market over the past 30 years. The best illustration I can provide shows the cost of starter culture as relates to the cost of milk. My calculations only include energy, labor, starter ingredient cost and cleaning cost. Any cost above the mentioned needs to be further addressed by your specific situation.

I did not factor in the efficiency of use related to milk volume. Many times milk efficiency is overlooked in cost comparisons. It is very easy to calculate. For instance, assume you run 1MM pounds of milk per day, seven days per week using 1.5 percent starter versus 0.5 percent starter you would displace 70,000 pounds of starter with cheese milk per week (105,000 pounds of bulk starter - 35,000 pounds of bulk starter) or about 3.6MM pounds of milk per year or 360,000 pounds of cheese per year. Manufacturing cheese using direct to the vat cultures would allow you another 35,000 pounds of milk per week or additional 1.8MM pounds of milk per year.

In conclusion, I will leave you with one final graph indicating the percentage cost of culture systems relative to the pay price for a hundredweight of milk. You can decide yourself to thank your culture supplier for the efficiencies.

Finally, I estimate that advances in culture technology in the US have saved the cheese maker approximately $600-800 million since 1975. It always makes me wonder if even a portion of this savings were reinvested in research and development towards starter culture development what our technologists may have developed. 

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:

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
Mother Cultures
Initial Thoughts


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