Back when I first started noticing these things, in junior high school (1977-80) I think, I recall learning that “whole” cow milk contained 3.8% milkfat.
I just noticed recently that the whole milk at my local grocery store is only 3.25%.
Has this actually changed over time, or am I simply misremembering (or misunderstood it 40 years ago)? According to Wikipedia, “average” cow milk contains 3.6% milkfat.
Standards differ in different countries, and…
Also
It’s been 3.25 as long as I can recall, back to the 1970s
The fat content in milk varies by cow breed, as well. As this site shows, some breeds (such as Guernseys and Jerseys) produce milk with a higher fat content, while Holsteins produce a lower fat content.
My understanding is that, since they produce more milk in the absolute compared to other breeds, Holsteins have become the breed of choice for most U.S. dairy farms (this article on Mother Earth News cites USDA figures, indicating that 93% of U.S. dairy cows are now Holsteins). My wife’s relatives farm and breed Jersey dairy cows in central Illinois, and the breed has become pretty rare on dairy farms.
I suspect that, if the fat content in whole milk in the U.S. has gone down, the move to Holsteins may be a factor.
It varies a lot. In Japan the fat percentage is displayed very prominently on the packaging, and the price tends to be higher for higher fat content.
During my childhood 40 years ago, milk was noticeably creamier in summer than in winter - I don’t know if that’s still the case.
I’ve been meaning to ask this very question! When I was growing up (in Ontario in the 60s and 70s), I remember “homo” milk (yes, that’s what we called it, short for “homogenized”) being 4% milk fat, but as you note, it has now fallen to 3.25%.
Same here. My homo milk in the 1980s and 1990s (Lucerne brand) was always 4%. I’m pretty sure it was still 4% as late as 2003. But now it seems that it’s 3.25% everywhere. I’d like to know when this changed and why.
The local whole milk around here is about 3.4% In Vienna I stayed at a hotel with a breakfast buffet, and they had an array of milk pitchers on ice with various fat percentages written on them, from skim to cream. I found the fours and fives the best. Then it started getting into “half and half” territory. I wish I could buy some 5% milk here in the states. It’s the little things about foreign countries that really grab you.
The output produced by cows will vary over the year depending on their diet. But in the modern industrial dairy industry they take the raw milk of thousands of cows and formulate the end products out of the various constituents. So it doesn’t matter if in January the cows are producing 2% milk and in July they’re producing 4% milk, what gets sold by the big dairies is always the same. Any excess skim or excess fat is diverted to various other dairy products like powdered milk or butter or whatever.
Maybe the stores should start selling third, third and third.
Heck, I always heard whole milk had 3.5% butterfat. The USDA standard (at least the 2001 document I found) is “not less than 3.25 percent total milkfat.”
I remember non-homogenized milk, delivered by a milkman, in glass pint bottles with a foil cap on top. The top inch was creamy.
In the U.S., federal regulations state that “whole milk” must be at least 3.25% butterfat. Milk straight out of the cow is usually more than that. It depends on the breed (an average of 3.6% for Holsteins to 4.6% for Jerseys) but also depends on the time of year and diet of the cows. Since cream is worth more than milk, dairy processors have an incentive to remove the excess cream (which is allowed under federal regulations) and sell milk that is exactly 3.25% butterfat, or very slightly more.
I’m not sure when the federal standard was set, but the original regulation was published in 1977 (if I understand right). I’m not sure if the 3.25% standard was part of the standard then. It was by the mid-1980s according to the code of federal regulations I found on Google Books. As of 1913, most states had their own standards for minimum fat content, ranging from 2.5% to 3.5% See Yearbook of the USDA, 1913. I’m not sure if any states still set standards higher than 3.25%
When I was in college, my microbiology instructor (also state inspector) told us of a local milk producer who blended milk from various small producers, so that it was just at the required levels for fat content, other nutrients that have standards, and yes, even the microbial count. It sold for a few cents less than other brands.
In other words, if the standards are known, then there’s surely producers saving money by manipulating the product to just barely pass. The O.P. may just now be noticing, or maybe its a new money making process.
As noted in post #2 above, modern milk production “involve(s) first removing all of the butterfat…then adding back the appropriate amount” - so the 1%, 2%, “whole”, etc. milks you buy are all basically skim milk to which fat has been added to the required level.
My knowledge comes from when I was a kid on a dairy farm. 50s 60s.
Whole milk in the store had some of the butterfat removed. It was against the law to sell "whole’ milk above a set level of butterfat. Requiring some of the butterfat removal from the “whole” milk. I know the milk we had in the house was way richer than the milk I had at friends houses.
Also what the cows eat will have an effect on how much milk they give and what the butterfat will be. The farmer is paid based on butterfat more than volume.
In the day of the family run farm the feed given to the cows was adjusted to increase butterfat. in the 40s and early 50 my dad was a milk tester. He had a round of farms he would visit every other week or so. He would test a sample of milk from each cow for butterfat. The farmer would adjust the grain the cow was getting according to the test results.
I’ve never heard of it being against the law to sell at a higher percentage, but I’m guessing if the law says whole milk must have at least X percent fat, and if people know they can get a higher price for that fat if they sell it separately, then the whole milk they sell is “because of the law” going to be X.0000001 percent. 
Wow, thanks for all the answers! This had been bugging me for a while now. Glad to know I wasn’t imagining things!
California sets the levels of butterfat in milk. And yes the public is not made aware that there is a cap on the limit.
This may have changed over the years.
I’m sure that when I was growing up in the 40s and 50s, it was 4%. Now, I’ve not seen anything but 3.25%.