But, first things first! While thinking of gallon, first think which country’s gallon is this?
As a matter of fact, the measurement of a gallon varies in different measurement systems, as in the imperial and American systems. Although a pound in both the UK and US systems is equal to sixteen ounces, the case with gallon is different. One imperial gallon is measured 20% more than a US gallon. Or put it otherwise, a 1.2 US gallon is equivalent to an imperial gallon. When talking about milk (normally full-fat milk), a UK or Canada gallon weighs 10.3 pounds or 164.8 ounce or 4.67 kg, while a US gallon weighs 8.6 pounds or 137.6 ounce or 3.9 Kg.
Further in this article, all measurements are mentioned in US gallons.
Now, to know the weight of a gallon milk, you need to understand the composition of milk, types and varieties of milk, and what part of constituents affect the weight.
Types Of Milk:
Milk itself consists of 87% of water, around 300 different chemical substances, and fat content that significantly add up to its density and thus to its weight. At present, a wide variety of commercial milk is available in the market, and all differ in their per gallon weight.
The weight of milk varies depending on the fat content it holds.
Milk that comes from different animals possesses different levels of fat content. For instance, sheep’s milk is a bit richer in fats than cow’s milk. So with the increase in density, a gallon of sheep’s milk weighs a bit more than cow’s milk. That’s the reason why ewe’s milk serves as a prime ingredient for delish yogurts and cheeses.
Similarly, there are some other alternatives to milk like nut milk that contain suspended material for milky texture. Such products vary in weight depending on the amount of suspended material, which makes them denser and heavier.
1. Whole Milk
Normally, when talking about the whole milk, people refer to the milk that comes straight from cows and is not processed any further. The consumer gets whole milk with all the constituents that milk possess naturally.
2. Skim Milk (Fat-Free Milk/ Non-Fat Milk)
On contrary, the skim milk has no fat content left in it. This fat-free form of natural animal milk affects its weight directly.
A Gallon of Whole Milk versus Skimmed Milk
A gallon of whole milk weighs about 8.6 pounds while a gallon of skimmed milk contains 8.5 pounds. Why 0.1 pound lesser?
Well, it’s the lower fat content in skim milk that makes it 0.1 pounds lighter than the whole milk. The whole milk contains 3.5% fat. On the other hand, skim milk (non-fat milk) has just 0% fat. And that makes the difference. People on a fat-free diet can happily rely on skim milk.
3. Low-Fat Milk
Low-fat milk contains 1 % of fat.
4. Reduced-Fat Milk
Reduced-fat milk contains a 2% fat content. This makes it slightly lighter in weight than the whole milk.
Is Milk Heavier Than Water
As mentioned above, milk has 87% of water constituent. The rest of the 13% of constituents is other substances, mineral and fat content. All these substances and fat content pose a cumulative effect on the density of milk. Resultantly, it makes a gallon of milk a bit heavier than a gallon of water.
In US gallons, weighs of a gallon of water is about 8.33 lbs, and a gallon of milk is 8.6 lbs. Thus, water weighs about 3% lighter than milk.
What About A Gallon Of Milk Without Water?
If you flash-heat the milk until the water content is evaporated, you will get the condensed milk, or you can convert it into dried powder.
The benefit of powdered milk is that it has a longer shelf-life than the fresh products, plus huge gallons of milk can be transported easily if the water part is removed which forms the bulk of milk.
Besides being used as an ingredient in other products, powder milk serves as a medical product for babies who are on alternative nourishment to breast milk. The desired amount of powder milk can be reconstituted with water when needed.
Conclusion
How much a gallon of milk weighs depends on the country you live in, water and fat content, and the type of milk you are weighing.
There’s no specific answer to this question. It is different under different conditions.
