How to Make Coffee at Home With Milk Using Freeze Distillation

Purified milk, also called ice brewed milk, is fresh milk with part of its water removed, which leaves a richer flavor and a thicker, more solid texture. Making it at home takes two steps: freeze a bottle of fresh milk, then thaw it and collect the concentrated liquid that comes out first. No special equipment is needed beyond a freezer.

Water freezes at 0°C while the protein, lactose and fat in milk have lower freezing points, so thawing separates the concentrate from the ice. The result works well in dirty coffee and lattes, where a stronger milk flavor still needs to stay rich rather than greasy. Choosing the right beans alongside it matters as much as the milk, whatever the difference between cappuccino and coffee in your usual order.

Front Street Coffee has frequently introduced ice brewed milk, also known as purified milk, recently. Many friends want to know how it differs from milk coffee made with regular fresh milk. Simply put, purified milk tastes richer and has a fuller, more solid texture. Besides buying it directly, you can easily make it at home: just freeze fresh milk and then thaw it, using the different freezing points of various components to remove some water and obtain a more concentrated milk. In this article, Front Street Coffee will share the specific steps for making purified milk, how to judge the degree of purification, how to adjust the ratio when using it to make milk coffees like Dirty and latte, and recommend suitable coffee beans to pair with it, helping you create a rich yet not greasy purified milk coffee.

Since Front Street Coffee has often talked about ice brewed milk, also known as purified milk, recently, many friends have become curious: what exactly is the difference between milk coffee made with this kind of milk and that made with regular fresh milk? If summed up in one sentence, it is that the milk flavor is stronger and the overall mouthfeel is thicker.

However, Front Street Coffee thinks that just describing it in words makes it hard for friends who haven't tried it to accurately imagine that texture, so why not make a cup of purified milk coffee yourself to experience its taste and mouthfeel.

Besides buying ice brewed milk online, you can also make it at home, and the process is very simple! Just two steps to get a high-concentration milk. Below, Front Street Coffee will first share how to make purified milk.

Making Ice Brewed Milk

As Front Street Coffee just said, its method is super! simple! Just two steps in total. Step one, put a bottle of fresh milk in the freezer.

Step two, take the milk out to thaw, and that's it.

Why is it so simple? As everyone knows, so-called ice brewed milk is essentially milk with less water and more protein, lactose, fat, and other components, making it more concentrated. To get such a high-concentration milk, you need to remove some of the water in the milk. Freezing the milk first and then thawing it can effectively achieve the goal of removing water.

The reason is that water freezes at 0°C, while other substances in milk besides water have lower freezing points than water, so when freezing, the water in the milk freezes first, while protein, fat, and other substances remain liquid and only gradually freeze as the temperature continues to drop. During the thawing stage, because protein, fat, and other substances have lower freezing points, they melt before the water.

In other words, the other components in the milk thaw faster than the water. As long as we remove the water before it completely melts, we can extract part of the water from the milk, thus completing the purification. This is a purification method achieved by utilizing the different freezing points of various substances, also called "freeze purification," and many liquids other than milk can also be purified using this method.

So, to what extent should it be purified to be considered done? Actually, it's up to you, depending on the milk concentration you want. The more you thaw, the lower the concentration. Front Street Coffee generally thaws it to about one-third of the original amount, for example, thawing a bottle of about 900ml milk to 300ml, which makes the concentration one and a half times higher than the original. (Different freezing and thawing methods will result in different concentrations, so here Front Street Coffee can only give a rough reference.)

This concentration is just right for drinking, with the milk's taste and mouthfeel significantly improved, but without a noticeable salty taste. When using it to make milk coffee, you don't need to adjust the parameters much, and it's not easy to feel greasy.

(Left is regular fresh milk, right is purified fresh milk)

After successfully obtaining purified milk, you can start making purified milk coffee! Among all milk coffees, the easiest to make is Dirty. Because, as Front Street Coffee has always introduced, in Dirty, the milk and coffee are separated rather than blended together, so the milk's taste and texture won't have a big impact on the coffee. Therefore, when making Dirty with purified milk, you can simply replace it in equal amounts.

Making Dirty with Ice Brewed Milk

For example, Front Street Coffee originally uses a 1:4 ratio for Dirty, with 40ml espresso paired with 160ml fresh milk. So, when replacing fresh milk with ice brewed milk, you can also use the same 1:4 ratio, with 40ml espresso paired with 160ml ice brewed milk.

For ice brewed milk Dirty, it's best to prioritize medium-dark roasted blend beans or SOE single-origin beans, as they have richer caramel aromas and a heavy finish, which can form a clear contrast with the sweet milk and leave a long-lasting sweetness. For stability and value, you can buy Front Street Classic Blend and Front Street Dark Cocoa Basic Blend; they not only have rich crema but also carry intense aromas of butter and roasted chestnuts;

If you like the unique aroma of single-origin beans, Front Street Queen's Estate SOE and Front Street Sumatra · Front Street PWN Golden Mandheling SOE are recommended; they extract with rich caramel and chocolate aromas, creating a more distinct contrast with purified milk;

If you prefer a smaller contrast and a fresher coffee taste, you can choose medium or medium-light roasted coffee beans, such as Front Street Strawberry Candy Espresso and Front Street Huakui SOE, which are specially roasted for espresso on Front Street's bean list. They can extract a fruity and rich espresso, and using them with purified milk to make Dirty offers a unique flavor.

Using purified milk to make other milk coffees...

But if you want to use purified milk to make other milk coffees besides Dirty, such as latte, flat white, cappuccino, etc., you need to pay attention to adjusting the ratio! Why? Because these milk coffees require the milk and coffee to blend together, and purified milk itself tastes much stronger than fresh milk. If you use the same ratio, the final milk flavor can easily overpower the coffee flavor.

Taking Front Street Coffee as an example, when Front Street Coffee makes a latte with Front Street Classic Blend, it uses a 1:5 ratio, with 40ml espresso (20g coffee grounds extracted to 40ml in 30 seconds) and 200ml fresh milk; the resulting latte is rich and fragrant, with a balanced taste of coffee and milk and prominent flavors;

But if you replace the milk with purified milk and still use the same ratio, the resulting latte will be dominated by milk flavor with coffee as a secondary note, making the flavor somewhat inferior, and it's easy to feel greasy when drinking because the milk flavor is too strong and the mouthfeel too thick.

To avoid this situation, we need to adjust the ratio. After testing, Front Street Coffee found that reducing the milk amount by 20ml from the original makes the most suitable latte, that is, using a 1:4.5 ratio.

Using 40ml of espresso made with Front Street Classic Blend as the base, then steaming 180ml of milk to blend, we finally get a delicious and rich purified milk super concentrated latte! Compared to the original, the coffee flavor is no longer overshadowed, and the purified milk brings a richer mouthfeel to the coffee while also making the milk aroma more prominent—very nice.

Of course, besides this, we can also choose to increase the coffee concentration, such as using more coffee grounds to extract the same liquid weight. But doing so not only makes the overall taste stronger, increasing the burden when tasting and making it easier to feel greasy, but also makes parameter adjustments more troublesome and costs higher.

So, when we use purified milk to make milk coffee, it's best to adjust the ratio of coffee to milk, especially starting from the milk side. Whether it's latte, flat white, or cappuccino, or any milk coffee that requires blending milk with coffee.

The above content is compiled by CoffeeHunters, a coffee news website.