If you’re a big fan of coffee, then you are well aware that some great types of coffee are not complete without the addition of a creamy froth, especially when it comes to cappuccinos.
It is essential to select milk that will whip up into a foamy head when making a beverage that needs a fluffy topping. So what is the best milk for frothing?
The best type of dairy milk to use when creating a foam is whole milk, as it contains an optimum combination of fat, protein, and carbohydrates. Frothability wise, oat milk is the most suitable non-dairy option due to its creaminess and thickness similar to that of dairy milk.
This paper will take a look at different kinds of dairy and non-dairy milk and explain why they are successful when it comes to producing foam. This text will investigate why certain sorts of milk produce foam more easily than the rest.
What Is Foam?
Seems like a silly question, right? A foam is any substance with air bubbles caught inside. In relation to coffee, this implies to the thin layer on top of the beverage in which air has been held in a fluid mixture, usually dairy or an alternative dairy product. At coffee shops, baristas employ steam-powered wands to infuse milk with air and warmth to generate stable and pleasing microfoam.
I realized that machines used in the home employ several of the same ideas to get comparable outcomes. I had a hard time understanding the process of making foamed milk with an at-home frother, such as making cold foam, so I consulted Dr. Thom Huppertz. He is a professor of Dairy Science and Technology at Wageningen University and the Editor-in-Chief of the International Dairy Journal, so I figured he would be familiar with the topic and would have the answers I was looking for.
Milk consists of water, as well as proteins, fats, and sugars. The three factors contributing to the distinct taste of milk are not of equal importance, however, we will primarily be exploring the first two components since they are responsible for the formation of hot milk and foam.
Protein
According to Dr. Huppertz at the Re: co conference, the proteins found in milk are remarkable. When we started talking on the phone, I questioned whether there were any other liquids I could froth besides milk, such as orange juice, that would produce foam. Yes, he said, but nothing that’s very stable. Only eggs possess the ability to create foam in a similar way to milk.
He went on to say that milk proteins have the characteristic of being able to dissolve easily in water, and they have the ability to interact with the surface of the liquid.
When making frothed milk, you mix in air into the liquid by shaking it at the top. You can produce foam by combining and stirring any substance with air, developing a solid foam which can keep air suspended in the liquid for a lengthy period of time. Due to the fact that milk proteins posses surface activity, they can hold on to whatever is distributed to their surface. When you are creating foam with milk, you are adding an enormous amount of air to the milk’s surface.
Heat also plays a part in milk frothing. The application of heat to milk will cause the proteins in the milk to separate from their closely wound coils. As the proteins start to expand, the parts at the beginning and end become exposed – the hydrophobic end that hates water, and the hydrophilic end that loves it. The hydrophobic ends are trapping air molecules to form foam.
Other items that contain protein may form a foam, yet it probably won’t be as prominent and could be less sturdy. A serving of whole milk typically contains eight grams of protein, while oat milk contains around three grams of protein. Both types of milk will generate foam, however it will require more agitation to produce the same quantity of foam from oat milk as with whole milk. If you check the amount of protein in your milk, you can estimate whether it will create a foam easily. You should give your milk a more vigorous shake when creating steam with any kind of plant milk.
Fat
Fat has an adverse effect on foam, but only if it’s in a specific condition. He stated that if the temperature rises higher than 40 degrees centigrade, all the fat will be melted and will not be destabilized any longer. When the fat present in milk is either a liquid or frozen solid, it will not interfere with forming a stable foam. When both solid and melted fats are included together, milk fat can create an unstable element.
Nonfat milk is the simplest type of milk to foam, and it stays whipped for a long period, though an excessive addition of air can make the foam excessively firm, bordering on brittle. Whole milk typically contains 3-4% milk fats, and is most suitable for creating a foam with a velvety and soft texture, similar to what you see at a coffee shop. I tested out heavy whipping cream, which has 40% milk fat, but it will not stay foamy like it does in a latte– instead it will only become whipped cream.
I conducted tests to find out which frothers could generate a fine, lustrous microfoam; an airiness that had tiny air bubbles that created a unified, smooth, and uniform consistency. I right away looked at the foam once the frother had completed its task, since the foam will begin becoming detached from the milk and start to go up to the top as it waits.
What Is Cold Foam?
I felt I needed to gain more knowledge regarding the testing of cold foam. In my area, cold foam drinks have gained prominence recently; beginning in 2018, they were added to Starbucks offerings. I haven’t come across many coffeehouses that take advantage of cold foam in any way other than to put it on in place of whipped cream.
I asked an anonymous former Starbucks employee how they prepared cold foam, and they said they simply use non-fat milk and a powerful blender. The lack of fat content helps the foam keep its density. I was uncertain about the purpose of the high-powered blender.
According to Dr. Hupays, these high-speed mixers are being utilized. The air is mixed into the milk, and the protein is responsible for keeping the milk stable. Agitating at a very fast rate can cause tiny bubbles to form, resulting in a nice foam. Alternatively, slower agitation can produce bigger, yet less delicate, bubbles, according to Dr. Huppertz.
This final section concerning the velocity of the stirrer was quite helpful for me, because I hadn’t previously realized that the pace of the stirrer was so essential. In their analysis of milk frothers, Cook’s Illustrated identified that they liked a handheld model that had a little less strength than similar versions more, which proved sensible when making warm beverages since it provided more authority over the frother. I thought about how quickly the frother worked when it created cold foam.
Why Do Some Types of Milk Froth Easier Than Others?
In order to make a delicious foam for your coffee, the milk must be heated in a specific manner.
The ability of the milk to stiffen into foam is connected to the quantity of proteins, carbohydrates, and lipids in the milk.
We will look into the two primary sorts of proteins generally found in milk—caseins and whey protein—and how they respond to the fat content of your milk.
Caseins
When heated, caseins are the proteins that determine the consistency of milk. The bundles of air bubbles are contained in the liquid, and once steamed, the bundles separate, creating the foam.
The amount of casein you use will decide whether you will get a creamy luxurious foam or a standard cup of coffee with milk.
Proteins
The amino acids in milk whey proteins can either draw in or push away water molecules.
When heating milk, the amino acids serve to create a film which contains the air molecules and confines them in the bubbles.
This layer of acids affects the sturdiness of your foam when creating coffee.
Fat vs. Proteins
It does not matter how much protein is there in the milk; the ratio of fat to protein will determine the quality of the foam.
For example, milk with lots of fat will become thick, dense foam when steamed:
The rich texture of the foam is delicious, however it is likely to dissipate quicker than other milks.
In contrast, using milk with lower fat content but higher protein will create a gentle, airy froth.
The foam will not have the same delicious taste as the creamy milk, but it will take far more time for it to dissolve.
It would be incredibly difficult to successfully froth all types of milk because they all have different levels of proteins, fats, sugars, and water.
Non-dairy milk varieties containing a high proportion of water and additives to compensate for the fat and protein missing from dairy milk are unlikely to froth well.
The Best Dairy Milk for Frothing
Many different types of cow’s milk exist and they all produce a satisfactory foam. The amount of fat included in your drink is up to you.
Generally, the highest fat content in milk will produce the most velvety and tastiest foam. Let’s explore more about your dairy froth options.
Whole cow’s milk for coffee froth
The most efficient frothing effect can be produced using whole cow’s milk as opposed to any other dairy or non-dairy milk options. The capacity of this milk to make foam is very noticeable when it is organic.
Organic whole milk contains the ideal proportion of fats, proteins, sugar and water, making it an ideal choice for creating froth.
Total milk can generate a luxuriously velvety and sugar-coated foam when it is heated to the precise temperature (150-155°F, 65-68°C).
As the whole milk is heated, tiny bubbles will appear as it is being frothed.
These bubbles mean the foam will taste extra creamy and be a more consistent foam that lasts on top of your drink for an extended period and is perfect for making a flat white:
The negative aspect of employing whole milk for producing foam is that the fat diminishes the air bubbles, making it harder for the froth to become dense.
Despite the wait, the result is definitely worth it.
In addition, the type of cow’s milk and its food intake both have a substantial influence on the flavor and contents of the milk.
Certain cow breeds, or those given a certain diet, will affect the level of sweetness and consistency of the foam.
2% milk for frothing
If you are aiming for a frothy texture similar to whole milk’s but with fewer fats, then 2% milk is the perfect choice.
2% milk can be utilized as a suitable replacement for whole milk when attempting to achieve an excellent foam due to it having the same amount of proteins.
Using 2% milk provides a quicker heating process and results in more microbubbles being produced than when using whole milk.
Given that there is less fat than protein, the casein clusters disintegrate faster and the milk foams up faster.
The ultimate choice between whole milk and 2% milk for frothing comes down to a matter of personal preference regarding taste and speed.
If you’re looking for a more sumptuous and sugary foam, whole milk is the way to go. If you want your milk to foam quickly, pick 2% milk.
Skim milk as coffee froth
Frothed skim milk will give you a different experience than full-fat or 2% milk would.
Because it has little or no fat, skimmed milk foams up more easily.
When steaming the milk, the proteins will instantly split, creating bubbles which are bigger and lighter than the tiny bubbles that appear in full-fat and 2% milk foam.
Remarkably, the bubbles that form in skim milk froth remain in tact for longer periods of time in comparison to the bubbles that arise in the foam of whole and 2% milk, even though the bubbles in skim milk froth appear larger.
If you use skim milk, the foam will stay firm for a bit rather than vanishing into liquid right away like it would with the other two options.
If you are looking for a milk that has very little fat and will create a thick foam and stay good for a long period, then skim milk is the perfect option for you to froth.