WCMA Notes: The Time is Now for Microfiltration

A Column Offered by WCMA Executive Director John Umhoefer

There’s a proven tool the U.S. dairy industry isn’t using — a tool that can assist with cheese output and profitability as the industry struggles with years of low milk prices for farms and lackluster cheese and whey prices.

With surging milk, tight margins, new tariffs and markets threatened by EU cheese-naming barriers, the U.S. can, with a simple memo from the U.S. Food & Drug Administration, open the door to use of microfiltration of milk, just as FDA okayed ultrafiltration for cheesemaking last year.

Milk filtration is the simple process of running fresh milk through sanitary rolled-up plastic screens. The holes in a microfilter are a little bigger than those in used in ultrafiltration, so water and lactose and small whey proteins slip through and bigger components of milk – casein protein and fat – are concentrated. The smaller holes used in ultrafiltration let only water and lactose slip by.

The dairy industry has been running milk through filters since the 1960s, and ultrafiltration on the whey side of the business – concentrating whey proteins – transformed the dairy industry in the 1990s and onward. Filtration to create a suite of useful whey proteins has brought countless millions of dollars into the dairy community.

The next logical move is microfiltration. Europe already has 40-50 cheese factories microfiltering milk for cheesemaking, so this isn’t a brave new world.  And this filtration of farm milk offers a host of opportunities.

First, microfiltering milk helps cheesemakers standardize the casein protein in milk entering the cheese vat – that means more consistent cheese year-around. At the same time, since the whey proteins are filtered away, any off flavors or bitter notes these proteins can bring in finished cheese are not present.

Second, cheese yield is improved – controlling and concentrating casein in cheesemilk means more cheese per vat. That production efficiency helps profitability because cheesemakers gain more product from the same equipment and labor inputs. Cheese plants that concentrate casein protein can run more vats per day and help soak up rising milk production. And the water removed in milk concentration can be used elsewhere in the plant – creating a more sustainable dairy plant that uses less groundwater.

Finally, removing whey proteins before they reach the cheese vat offers exciting possibilities. These whey proteins don’t move through the cheese make, so they’re free from milkfat, cheese culture, annatto color and salt.  These whey proteins are visibly clearer and have fewer off-flavors, because these proteins haven’t faced culture activity or rennet enzymes.  Sometimes called milk-derived whey or native whey, this dairy product has application in clear drinks, infant formula and countless other pure food applications.

Last summer, FDA issued a memorandum offering enforcement discretion for the use and labeling of ultrafiltered milk in cheesemaking.  In other words, FDA acknowledged the benefits of that filtration process and will not enforce standards of identity and labeling regulations that held back industry’s use of this simple filtration process.

So, what’s holding up FDA’s acknowledgment of microfiltration? FDA noted in 2005 that microfiltration changes the casein to whey protein ratio in milk, making this filtered milk nutritionally different (in their view).  But whey proteins always slip away into the whey during cheesemaking – filtration simply takes them out before the cheese is made, rather than during the process.

A 2018 study at the Center for Dairy Research, which was presented at the American Dairy Science Association meeting in Knoxville in June reported that ordinary cheesemaking always removes all but 1.5 percent of whey proteins from cheese, and removing around 50 percent of whey proteins from the milk in advance of cheesemaking (by microfiltration) still resulted in that same small amount of whey protein retained in cheese curd. This Center for Dairy Research study also found that using microfiltered milk to make cheddar cheese had no impact on the composition or quality of the cheese, but improved make efficiency.

Microfiltration is a proven tool, already in use around the world, that can make better cheese, improve the efficiency of cheese plants and open the door to new whey products.  It’s time for an industry push to gain approval for this process in cheesemaking.  Today, we need every tool to rebuild farm and dairy plant profitability.