A reprint of an article written a number of years ago for the cheese industry.
Traditionally, before the widespread use of laboratory cultures, cheese dairies would begin the season with no culture at all; allowing a culture to develop from the microbes in the environment, what we would call today, sour milk. Culture was seen as an influencing which bacteria of the many naturally in milk, would thrive. It is the bacteria in the cheese and their enzymes, which define the cheese, more or less. It is the pH, or acidity of the milk and the temperature that influences which bacteria grow, but they have to in the milk in the first place. That is where the culture comes in. It is a kind of insurance policy.
In the tightly controlled, sanitized environment of the cheese room today, lab culture, usually freeze dried, is used to ensure consistency in the production of large quantities of industrial cheese, as well as try and mimic the complexity of nature by adding carefully selected bacteria and enzymes called “adjunct cultures” to try and replace those missing from the milk, either because of how we feed and raise our herds, or because of pasteurization.
But the charm of so-called “wild” cultures is also their challenge.
What we have is a loss of diversity
When the labs went to pure monocultures they discovered why one bacteria in a wild culture may “win” over another, and the culprits are bacteriophages.
In the late 1800’s, in Scandinavia, scientists isolated lactic acid bacteria and began to provide it commercially. This led to a sea change in how cheese was produced. Originally the work of the farmwife in England, some of Northern Europe and the US, it became the province of men exclusively for almost a century, and the 40 lb. block grew rapidly in popularity in the US because of the percieved economic advantage of loading into train cars, also a new mode of industrial transportation. With it came a catastrophic loss of diversity in the dairy industries of Wisconsin and California from the turn of the century until the renaissance of artisan cheese that blossomed, roughly, starting in the early 1990’s.
As part of my research for the CMAB, which, seeing a chance to raise the prestige of California’s cheeses in the public’s eye, had decided to pour resources into driving that renaissance, I uncovered lists of cheese factories from this time. At the turn of the century in California, there were over 1400 dairy families making cheese. By 1992 it had fallen to around a hundred, a devastating loss to the diversity of the State’s agricultural heritage. But the growing interest in better tasting, less industrial food, had ignited another sea change happened. Ironically, the fledgling artisan cheesemakers had to work with equipment, cultures and laws that were created to help industrial production, as the old ways were practically lost.
From the use of raw milk for aged cheese, to the use of wood for aging the wheel, even to the use of bricks for making brick cheese, brave individuals stood up and fought for the right to do things the traditional way: including Ig Vella, who won the right to age on wooden shelves, and Joe Widmer in Wisconsin, the right to age initially in wet-heat, and use bricks, both by bringing elderly inspectors out of retirement who could remember the days when these things were common.
My research was done as part of an educational marketing document prepared for the CMAB on How Cheese Gets its Flavor, one aim of which was to encourage family dairy producers, with the aid of a handful of sympathetic technicians, to experiment with cheesemaking with wild cultures as a way of differentiating their product from more industrial cheeses. As cultures, like pasteurization, were a heavy financial burden for them to bear. It was not until later, and I do not think because of the work I did but because of a european influence that wild cultures did finally become used in some cheeses, though i would love it if somehow I made a little contribution.
A small producer uses a small vat, so if bacteriophage attacks the vat it is not a fatal economic loss like what prevented the industrial production of cheese pre-1800’s. Lose a few thousand pounds of milk on a regular basis and you end up in trouble fast.
Interestingly though, the research uncovered the fact that the natural cultures were much more resistant to bacteriophage than the lab versions, because they were more complex, but I will leave that to the scientists and technicians quoted below.
I know that the traditional way (of making cheese) started with milk. You have LAB (lactic acid bacteria-DS) in milk and if you do not pasteurize it will spontaneously acidify. Then you can use this coagulated milk to inoculate a new portion. The ones giving the best product you can grow in bigger portions and use every time until they begin to slow down, often the dairies used to add whey to the new portion to make it more resistant to phages. The mixed starter developed in this way were often very good, however, antibiotic treatment of cows kill the starters.
Prof. Lytte Josephsen
In fact, the more diverse your starter culture the less likely phage can “stop” your vat. But phage can still attack, changing your culture on any given day. Small variations in the cheese will occur depending which bacteria are active. Small variations can be a plus for artisan and farmhouse cheesemakers as it differentiates their product from a more standardized cheese, or a pain in the neck if what you need is consistency.
If you use back-slopping (a cheesemaking term for using some of yesterdays starter to create todays) you will not get the same cheese every day due to phage attacks. Another thing, I believe that non-starter LAB and surface flora are very important for the local influence. (Terroir)
Prof. Lytte Josephsen
Problems with phage can result from using direct to vat cultures for batch culturization. You can’t start with just any direct to vat culture; you need to work closely with a culture supplier to develop a proper culture, and no industrial culture can come close to the complexity of nature.
“I know that many problems with phages are related with an improper use of direct cultures (direct cultures that are used as semi direct cultures)
Prof. Jorge Rynheimer, Argentina
“The following is from an email response to me from on the use of indigenous cultures in Italian cheesemaking from Professors Germano Mucchetti and Erasmo Nevian of the Instituto Sperimentale Lattiero Caseario, Lodi, Italy
The problem with all plant propagated systems is the potential for variable rates of acid production. The production of in house cultures that are more phage prone are usually not made with the aid of adding back some of yesterdays whey. I know of one Italian cheese plant in the US that used yesterday’s whey to inoculate heat-treated whey to produce culture very successfully. They use this culture along side a commercial direct vat set daily.
Even if in Italy a lot of cheeses are made using raw milk and “natural” starters, the great part of this production is represented by Parmigiano Reggiano and Grana Padano (the parents of the globalized “Parmesan”): their whey cultures, composed mainly by thermophilic lactobacilli with sometimes a minor component of streptococci, are the most studied and well-known.
The cultures typically used (when used) for the production of the other raw and/or artisanal cheeses are represented by milk starters or whey starters. The “milk starters” (lattoinnesto in Italian) are microbial cultures derived from the heat treatment (60-65°C per 10-20 min) of fresh raw milk, then cooled to 42-45°C and incubated at those temperatures until pH drop to 5-5,4 (generally within a time ranging from 6 to 18 hours): their flora is composed mainly by a natural mix of several biotypes of Streptococcus termophilus, with the presence of some enterococci, if they occur in the raw milk. With this kind of starter are produced some Mozzarella cheeses (e.g. Mozzarella Tradizionale: you can see on the web at www. europa.eu.int/eur-lex/ the standard of production), mountain cheeses like Montasio, some varieties of Pecorino (sheep) cheeses and many industrial soft cheeses, like Crescenza etc.
The whey starters (sieroinnesto in Italian) are microbial cultures obtained incubating the whey deriving from the cheesemaking (only for cheeses from raw milk) at opportune temperature (specific for every cheese) until the right degree of acidity is reached.
Differently form (from the- DS) USA, as we suppose you well know, in Italy many producers of the standard cultures are (more or less) strongly interested also in the production of “natural” or “undefined” cultures for the artisanal cheeses. The approach however, depending on many local variables, may be very different: when it is economically feasible, a culture laboratory offers to the cheesemaker a ready to use liquid culture, giving at the same time a functional mix of viable cells, lactic acid and, may be, aroma from the original, while avoiding drastic changes in the cheesemaking technology.
In other cases, a smaller local laboratory can produce direct to vat starters, composed by strains isolated from milk, cheese and/or natural starters typical of that variety of cheese. For the cheesemaker, when these cultures are available, the choice is between the cost of buying something that until this moment was inexpensive (or apparently) and the reduction of the variability associated to the self-production of the starter.
The problem, for our artisanal cheesemakers, is to reduce the range of variability: the natural cultures are a strong instrument to assess the imprinting of the cheese and to link cheese, origin and producer, (TERROIR) but there is an difficult risk to have an excess of variability that leads to obtaining unidentified cheeses (a mix of good, normal and defective cheeses). In Italy some … combine the use of natural cultures with selected ones, giving to the former the role of improving the aroma of the cheese and to the latter the technological aim to produce lactic acid and so on.“
Germano Mucchetti and Erasmo Neviani
I can give you a reference for phages in cheddar cheese production where they a few times a year grow the mixed undefined starter up and divide it into small sample, which they use for making cultures they use for the cheese milk. The reference is : Nielsen, E. W. 1998. Long-term use of a cheddar starter and development of phages with homology to its bacteria. International Dairy Journal 8:1003-1009
Dr. Lyette Josephsen
Terroir as defined by R. Drouhin, Vice-President of the INAOA terroir is a spread of land whose unique agricultural potential can be imprinted into the products cultivated on it. Terroir doesn’t exist unless a person determines by luck or observation, reflection or experimentation, the best agronomic approach and the most appropriate method to make a product that exemplifies this unique and original potential. Within a clearly defined geographic area, how successfully and completely these characteristics of terroir are able to be expressed depends directly on how they are produced.