Flavor Differences Between Bock Latte and Regular Latte How to Make Bock Milk

Introduction to Eisbock Milk Coffee

Recently, coffee shops big and small have been rolling out Eisbock milk coffee, largely thanks to the launch of "Eisbock" refrigerated concentrated milk by Bihu. But even before that product hit the market, some cafes were already featuring Eisbock milk coffee as a signature item. So how did they make their Eisbock?

What Is Eisbock?

"Eisbock" is transliterated from the German word Eisbock, which originally refers to the freeze-distillation process used to purify beer, also known as German ice beer. The principle is to separate substances according to their different freezing points. Apply the same principle to milk and you get what we call Eisbock milk.

In milk, water freezes at 0°C, while other substances (protein, fat) freeze at lower temperatures than water. If you place milk in a -20°C environment, the water in it freezes into ice first, and only when the temperature drops to each substance's own freezing point does it gradually solidify as well. During melting, the other substances release more easily while the ice melts slowest. By exploiting these different freezing points, we achieve water-milk separation and obtain a far more concentrated milk — that is Eisbock milk.

How to Make Eisbock Milk the Simple Way

FrontStreet Coffee stores do not sell Eisbock coffee, but we can show you how to make it at home. The materials are simple: a carton of milk and a container to catch the drips.

1. Place the entire carton of milk in the freezer. FrontStreet Coffee uses 946ml cartons of Kowloon Dairy fresh milk, frozen for 12 hours until the milk has frozen into a solid block. The frozen carton will look noticeably swollen, and pressing it firmly will tell you it is rock hard — confirmation that it has completely solidified.

2. Take the milk out of the freezer, open a small spout in the carton as you normally would, and set the carton upside down above the container. Then cover both the carton and the glass container with clean plastic wrap (a plastic bag works too) and secure it with tape. This does two things: it stabilizes the structure so nothing collapses, and it blocks outside contamination, especially moisture from the air — the wrap prevents water vapor from condensing into droplets and dripping into your container.

3. Simply let it melt at room temperature. The milk will drip into the container drop by drop, typically releasing 40%-60% of its original volume. If you prefer an intense milky aroma, collect only 40%; for a normal balance, choose 50%; if you hate to waste milk, go up to 60%. After a long 4 hours we collected 450ml of Eisbock milk — so from one 946ml carton of fresh milk, 450ml of concentrated Eisbock.

What Does Eisbock Milk Taste Like?

The high-purity milk that Eisbock produces has a stronger milky aroma and noticeably more body. In our tasting, FrontStreet Coffee found the milk extremely sweet and quite mellow — after drinking Eisbock milk, regular fresh milk tastes as thin as water by comparison. That said, a full glass of Eisbock milk can feel overly sweet and heavy precisely because of its concentration.

Which is exactly why Eisbock milk paired with espresso is the perfect match — think of the Eisbock Dirty that has become so popular in coffee shops.

How a Dirty tastes depends above all on the espresso beans. FrontStreet Coffee stores use their own roasted "Sunflower Warm Sunshine Blend," composed of 70% Honduras Sherry coffee and 30% Yirgacheffe natural red cherry coffee. The whiskey, vanilla, and cream notes of the Sherry component combine with the tropical fruit and fermentation character of the red cherry to create a rich aroma and silky mouthfeel. The first sip of an Eisbock Dirty delivers deep coffee flavor with whiskey, vanilla, and berry notes; from the second sip onward, as the cold concentrated milk blends in, you get a cocoa-and-cream texture. The finish lingers with the sweet fragrance of strong coffee and milk — beautifully layered.

FrontStreet Coffee Recommendation

A concentrated milk base like Eisbock needs an espresso with crema to match. FrontStreet Coffee's Classic Blend was designed specifically for espresso machines and moka pots, and its greatest strength is crema beyond compare — even a beginner with a basic home machine can pull a dense, silky golden foam. Built on the traditional Mamba formula with a full-bodied, mellow character, it suits seasoned drinkers and newcomers alike, and it covers exactly the drinks an Eisbock milk coffee depends on: latte, cappuccino, and Dirty.

Not chasing maximum crema? FrontStreet Coffee's Black Cocoa Blend uses 100% Arabica beans with ample crema and a mellow cup at a friendlier price, while the long-running Premium Blend pairs Brazil Cerrado with Colombia Huilan for that classic, familiar espresso flavor — with Brazil leading the profile, your latte gains layered almond and walnut nuttiness that stands up beautifully to sweet, concentrated milk.