Direct to the Vat Cheese Cultures, Part 2
See Part 1

Volume 132, No. 43 - Friday, April 25, 2008

Last week I addressed that the cost of raw materials to manufacture bulk starter media were escalating the past 18-24 months. However, why is there an argument that the new generation direct-to-the-vat cultures are so cost competitive while the older format is still cost prohibitive?

“In the new era of direct set, the big advantage is that it is cheaper than in the past,” said Dean Sommer, a cheese and food technologist with the Wisconsin Center for Dairy Research. One of the reasons they got the cost down, Sommer theorized, was putting Streptococcus thermophilus in the starter.

In fact, the culture manufacturers will admit the addition of S. thermophilus with an additional growth stimulant. So, at the end of the day, you are making cheese with basically a themophilic culture. Great for pasta filata/Italian cheese varieties.

But, what does this do to differentiate our American cheese varieties and what are the consequences of manufacturing American cheese with thermophiles?

“The old direct sets were slow, typically slower (to make acid) versus bulk set,” Sommer said. “So they put the thermo (Streptococcus thermophilus) in there to speed it up, but now your cheese browns, your whey browns and you have some of those other issues.”

Other cheese plants are recognizing this same issue. Because the S. thermophilus does not ferment the galactose molecule of the disaccharide lactose, this residual sugar plays a role in the Maillard Reaction as well as plays a significant role in effecting flux rates in filter systems and sticking in dryers.

“To me, the biggest issue with the new strains is the thermophilic/ mesophilic and the galactose and browning,” Sommer said. Sommer has had a number of cases in his position at CDR, where cheese companies would call him, or their customers would call him, asking “why is my Cheddar browning now?” or “why is my Monterey Jack browning now?”

“That’s the biggest Achilles heel for that system right now. No doubt about it,” Sommer said. “It’s that browning issue.”

In addition, Sommer said from a whey standpoint the mesophilic and thermococcus form a synergy that produces acid more rapidly, affecting the whey.

Some of the recent calls I have received are from cheese processors that say that “my cheese isn’t breaking down the way it used to, it won’t cook, I see uncooked particles.” I have not concluded that some of these problems are directly attributed to the new format of direct-to-the-vat cultures but recognize it as a potential.

If cheese is not breaking down properly one would not only consider culture but certainly consider calcium, pH and salt residual very important to cheese breakdown. Many times the problems arise from fortified or concentrated milk and retained/residual calcium.

Surely, if there isn’t enough initial acid development because of the culture the residual calcium will play a role. In any case, one of the factors can be the culture addition. The new direct-to-the-vat cultures do not provide flexibility to increase starter in incremental amounts to adjust for milk solids/equivalent in a cheese vat.

So is it the cheese cultures’ fault? This is where Dean and I really agree, “The cheese makers must take the biggest share of the blame for some of the problems associated with the new direct-to-the-vat cheese cultures. The cheese makers insist on speed. They want to make it in 2½ hours and demand the cultures have to do that.”

How does this pressure to perform effect the culture manufacturer? Sommer says, “it forces the culture houses to put S. thermophilus strains in there to make it economical and work in the desired make schedule.”

Sommer said some of the parameters the cheese makers put on the culture houses, paint them in the corner. “We want it cheap. We want fast, speedy acid production. It forces the cultures houses to blend their cultures in a way that may cause other potential problems.

“If the cheese maker would say they can live with the three-hour make or the 3:15 make then they (culture houses) might be able to come up with some direct sets without the thermo in there.”

But, Dean said, “culture houses are going to have to work through these issues.” “They are going to have customer complaints from foodservice or companyies using the whey as an ingredient. They are going to have performance issues with whey products and cheese products.”

Dean and I differ in opinion with these statements. His observations are correct but it is not a stand-alone option for the culture houses. We, as an industry, have to grow into these new challenges. As an industry we need to continue to bring new technologies to the forefront, take new challenges and risks and work with the tools at hand.

Making cheese faster, using higher concentrated milk will drive the industry, contending with higher buffering capacity because of higher milk solids, dealing with higher lactose/galactose concentrations, trying to solubilize more calcium from the casein. These issues are independent of starter culture activity but play a vital role in culture performance and ultimate cheese breakdown.

I reserve some very biased opinions on the future of the cheese culture market. I have strong opinions on how to pursue a successful program. I will address this in my next article when I have the opportunity to interview some of the various culture companies and what their opinion of the future might lead.

However, because Mr. Sommers was so graceful to offer his time and opinions I will leave this article with his visions and opinion of the future of culture options.

“In the near future I see them finding a way to eliminate thermococcus for the American style cheese. To get rid of the browning problem. I also see the next development will be to isolate more strains with adjuncts and other flavors for they can more customize the flavors that you want.”

Sommers’ outlook, “aged Cheddar has distinct flavors. I envision a culture house will be able to target specific flavor profiles. Do you want your flavors with sulfur notes? Do you want your flavors more sweet/Swiss flavor profile? Culture houses will be able to target those flavors,” Sommer said.

“Not tomorrow, but, someday using adjuncts to provide more complex strain development.”

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

Direct to the Vat Cheese Cultures, Part 1
Starter Culture Development
Mother Cultures
Initial Thoughts


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