The Flavor of Milk

Linda Drendel with a baby calf

Last fall, the Field Moms toured Dale and Linda Drendel’s family dairy farm in Hampshire, Illinois. They care for dairy cows and grow crops to support them. They sell their milk to a local dairy.

My big question of the day was about the flavors of milk. Why does the milk I buy (2% conventional) have such a consistent flavor year-round? What is it about organic/ultra-pasteurized milk that some people think it tastes better than non-organic milk?

I found out the answers are actually simple and straight forward. There are several factors that play a part and they include the cow’s diet, modern refrigeration, heat treatment of the milk, butterfat content, and packaging.  

One thing I did not know before the tour is that milk flavor testing is one part of a long list of test criteria (including anti-biotics and hormones) for each and every batch of milk put on the market. Consumers expect a consistent product and that is the purpose of the flavor test. An actual human, experienced in flavor testing, does the taste testing in a lab at the dairy. Any hint of an off-flavor in a batch of milk, such as onion flavor, for example, would cause the entire batch to be rejected. (Wild onion is a common weed sometimes consumed by dairy cows grazing in summer months.) We were told batch rejection does happen, but it's rare.

When I was growing up in Western New York, our milk tasted different in the summer and winter. In the summer months, the cows were out to pasture grazing on all sorts of grasses. In the winter, the cows were indoors with a diet of hay and silage. This change in diet caused the milk to taste different from winter to summer. (For more information on what dairy cows eat, see note 1 below.)

So, my first question was , why do we not taste that flavor change in the milk we buy in Chicago? I learned there were two possible reasons. The first is that many large dairy farms no longer put their cows out to pasture in summer months; therefore, their diet is consistent year-round and, subsequently, the flavor is consistent year-round. Another factor is that the equipment used at every step of milk production from the milking parlour, to the storage tanks, to the delivery system and dairy plant, all the way to our homes and including our refrigerators, is much better than it ever was at keeping milk at the proper cold temperature. Keeping the milk at the appropriate temperature helps preserve a very consistent flavor.

My next question, what makes someone think ultra-pasteurized organic whole milk tastes better than non-organic milk? The answer to this was surprisingly simple. As we all know, all milk at the super-market is pasteurized; but, some milk is labeled ultra-pasteurized, particularly milk labeled organic. So, what is ultra-pasteurized and how does that affect flavor?

First, we were reminded that pasteurization heats the raw milk up to a specific temperature and that temperature is held for a specific time. The temperature and duration depend on the product, the sugar content, and the fat content; but, generally, regular milk might be heated to somewhere around 150 degrees Fahrenheit for 30 minutes. This kills harmful bacteria such as Salmonella, E.coli, and Listeria. The ultra-pasteurized label tells us that the milk was heated to a much higher temperature, maybe nearly 200 degrees Fahrenheit, for just a few seconds. This kills all bacteria and enzymes and the milk is then considered sterile. Ultra-pasteurization produces milk with a burned, or nutty, flavor which some people prefer. (For more information about organic milk, see note 2 below.)

The third factor that affects the flavor of milk is butterfat content. If I remember correctly, we learned that all the fat is taken out of the raw milk when it comes to the dairy. Later, it is put back in and homogenized (mixed so that it will not separate) to make skim, 1%, 2%, or whole milk. Of course, the more butterfat in the milk, the creamier the milk tastes. (For more about butterfat and the cows that give it, see note 3 below.)

The fourth factor is the packaging. We can buy milk in cardboard cartons, plastic jugs, and glass. Each of those may impart (or not, in the case of glass) a different flavor into the milk.

Below are a few additional notes about what dairy cows eat, what makes milk organic, and what makes different types of cows special (other than their good looks and sweet personalities, of course).

Dale Drendel talking with the Field Moms
about the diet of his dairy cows

1. Dale Drendel showed us what their dairy cows eat. It is actually a fairly complex blend of some basic ingredients. They grow corn and alfalfa to store for winter feed. Some corn is cut and made into silage, which is the whole plant shredded to produce a nutrient-rich part of their diet. Corn may also be harvested for grain. Alfalfa is made into silage, but it is commonly cut for a nutrient-rich hay, as well. Hay is a big part of the dairy cow’s diet; it is their main source of fiber and necessary for good digestion. A surprise, to me, was to see whole cottonseed in the cows’ diet. Cotton isn't grown this far north, so that is a supplement that dairy farmers must purchase to add to their feed. It is a super-food, in a way, high in fiber, protein, and energy (fat). They also give the cows corn and soybeans in a ground-up form, for easier digestion, to supply energy and protein, respectively.

Giant hay bales in storage (over 1,000 lbs each!).
Hay is a necessary and main component
of a dairy cow's diet.

Silage (corn or alfalfa) is nutrient-rich and a main
component of a dairy cow's diet.

Grain (corn and soybeans) are main energy and
protein components of a dairy cow's diet.

Whole cottonseed is a great source of fiber, protein, and energy.
It is part of the Drendel's dairy cow diet. 

 

2. The organic label, alone, is not an indicator of a flavor distinction. Organic milk comes from a cow that has had a diet of (organically grown) silage, hay, and grain; and probably grazed in the pasture during summer months. The conventional cow will have the same diet, although grown conventionally, and may or may not graze during summer months. Often, it seems, the organic label is paired with the ultra-pasteurized heat treatment and that heat treatment is what gives that milk a distinct flavor.

3. We learned that there are many different breeds of dairy cows. A dairy farm will choose their breed based on the specific characteristics of the breed that they are looking for. The black and white spotted cow is a Holstein; and it is probably the most recognizable of all cows. They are the highest milk producing breed and most of the milk we consume comes from Holsteins. Jersey, Guernsey, and Brown Swiss are three other common breeds and they produce milk with a higher butterfat content.

A Holstein cow in the milking parlour

To learn more about Illinois family dairy farms or even try a new dairy recipe, check out the Illinois Farm Families Pinterest page!