Cool process promises better dairy products

Eric Hallstead takes a small sample of milk from the new freeze concentration unit. Courtesy of NYSEG

By Blaine P. Friedlander Jr.

The process that made "ice-filtered" beer famous will soon be giving you milkier milk chocolate, cheesier cream cheese, creamier ice cream and yummier yogurt.

That's because of a device called a freeze concentration processor, which is being tested in a pilot plant at Cornell's food science department. It is the only such processor in the country devoted entirely to milk, said Eric Hallstead, the Cornell pilot plant manager.

The dairy industry estimates that every year 60 million pounds of milk and whey are converted into powder, evaporated or condensed milk using a heat-evaporation process. But, said Hallstead, that method gives the milk a burned taste -- "kind of a heated flavor."

That is a critical issue to commercial food processors, who use condensed and evaporated milk widely in baking, ice cream, sour cream, cheese and a large number of products requiring milk.

Even though freeze concentration -- which eliminates boiling -- uses more electricity, it may be able to save food processors money because the concentrator requires less cleaning, has a longer processing run and makes more product.

David Barbano, Cornell professor of food science, explained that the machine used in heat evaporation has to be turned off for about six hours a day just for cleaning. The freeze-concentration method allows the milk to flow freely through the machine for up to 30 days nonstop without cleaning. The total savings to the food industry from freeze-concentration could be enormous, Barbano said.

This new method of condensing milk also could be healthier for the consumer, he said. "With the freeze-concentration method, instead of heat, there would tend to be a lower count of bacterial spores," Barbano noted.

Brewers have been making ice-filtered beers -- which have a more concentrated flavor -- for years. The process has been tested previously for dairy use, but the Cornell pilot project will be used to make enough milk products for commercial food processors to test and taste.

Here is how it works: The milk is poured into the processor, where the water content, which is about 90 percent of the milk, is slowly frozen, leaving the crystallized water droplets to be scraped and washed away. The condensed milk solids are left behind.

The pilot project is funded by the Electric Power Research Institute and sponsored by New York State Electric & Gas Co. and by NIRO, the manufacturer of the freeze-concentration unit.