How much does a gallon of milk weigh?

In this brief guide, we are going to answer the question “How much is a gallon of milk weigh?”, discuss answers to other related questions like how much does a gallon of skim milk weigh, and how much does a gallon of cow milk weigh.

How much does a gallon of milk weigh?

The weight of a gallon of milk varies depending upon the breed of cow and the fat percentage of milk. In the US, a gallon of milk weighs 8.6 pounds (3.9 kg) at room temperature. While in the UK, a gallon of milk weighs 10.32 pounds (4.68 kg).

How much does half-gallon milk weigh?

As a gallon of milk in the US weighs 8.6 pounds, so if we deduct half of it, we get 4.3 pounds which is the weight of a half-gallon in the US.

How much does a gallon of skim milk weigh?

Milk with a fat percentage equal to 2% is termed skim milk. Due to a decrease in fat content, the weight of whole milk is affected. The weight of skim milk is measured in the same way as that of 2% and 1% milk. It may range from 1 to 78 g of fat in one gallon. Even though the amount is significantly low, it causes a very insignificant change in the total weight.

How much does a gallon of cow milk weigh?

As the milk of different cows is different depending on the breed, weight, and area in which the cow is present. Milk also affects the weather and feed of the cow. Therefore, it can not be adequately measured what a gallon of cow milk will weigh. Cow milk also has different percentages of fat in its milk, ranging from 3.25% to 5%. The measurement can be done on a weight scale considering the fat and measuring system before measurement.

How long can you leave milk at room temperature?

According to the US Food and Drug Administration (FDA), milk can be left at room temperature for only 2 hours. This is because the room temperature, or the temperature range between 40 to 140 degrees Fahrenheit, is a perishable commodity for microorganisms, particularly bacteria. So, the 2-hours benchmark can become 1 instead, in case the temperature exceeds 90 degrees Fahrenheit.

How does milk spoil?

Milk is home to bacteria, such as Lactococci and Lactobacilli. At temperatures above room temperature, these bacteria breed and reproduce. These probiotic bacteria change the milk sugar, lactose, into its compositional units; glucose and galactose. Later on, the formation of lactic acid starts, as proved by the familiar tangy smell and taste. As the casein develops, the curdling process starts. As milk deteriorates further, the bacteria take over the fats, which causes the occurrence of molds.

Spoilt raw milk may become inedible as it curdles and gains its distinct sour taste and odor. However, it does not need to be discarded, as curdled milk is used to make cheese, cream, and kefir.

On the other hand, pasteurized milk does not become sour due to the absence of bacteria that are responsible to cause the milk to curdle. Instead, it rots and becomes unfit for consumption.

When the milk is spoiled, it develops undesirable characteristics. Even if milk seems to be safe, you can expect bacterial growth to start at a temperature greater than 40 degrees Fahrenheit. As milk spoils, you can detect a rancid and sour smell. The texture and consistency of the milk change too and the color becomes pale with a yellowish tinge.

Drinking spoiled milk can cause you to be a victim of food poisoning with general symptoms of vomiting and diarrhea. Therefore, it is better to just toss off the spoiled milk rather than risking your health.

How can you store milk?

So, from the above discussion, we come to an end that the milk should not be left out of the fridge and especially not overnight. 

Aseptic milk, packaged after processing at an Ultra High Temperature, will last for 6 months if its seal was left intact. However, an opened tetra pack will spoil if left out of the fridge overnight. Pasteurized milk can not be left out at room temperature for more than 2 hours.

The pasteurization process kills bacteria by heating the milk at high temperatures. After potentially harmful microorganisms destroy, then it is aseptically sealed to ensure its longevity. Once the seal has broken, pathogenic microorganisms cause the milk to spoil.

Traditional milk, on the other hand, does not undergo such a process. Therefore you can expect it to have a shorter life, even if it has an intact seal.


In this brief guide, we answered the question “How much does a gallon of milk weigh?”, discussed answers to other related questions like how much does a gallon of skim milk weigh, and how much does a gallon of cow milk weigh.



Hi, I am Charlotte, I love cooking and in my previous life, I was a chef. I bring some of my experience to the recipes on this hub and answer your food questions.

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