How to make 400-beat foam coffee: What are the ratios and steps? Why won't espresso foam up?

Whenever I open social media sites, my homepage periodically pushes tutorials for making foam coffee to FrontStreet Coffee. After a quick search, I found countless images. As more and more people try making it at home, failed cases have also become frequent, with many netizens saying that their homemade foam coffee looks completely different from the original version, and they don't know where the problem lies.

What is Foam Coffee?

With milk as the base, cloud-like dense coffee foam offers a rich, slightly sweet texture with intense coffee aroma. The first sip reveals an ice cream-like consistency, while drinking it in large gulps allows you to simultaneously experience the fluffy upper coffee layer and the bittersweet taste formed with the milk beneath—this is the foam coffee leading the DIY trend. Yes, it's the "400-stir coffee" that went viral online years ago.

From a structural perspective, the raw materials used for foam coffee are very simple: just coffee, milk, sugar, and an electric whisk. The steps are not complicated at all. However, to achieve a coffee foam that doesn't collapse on the milk and maintains a fluffy, dense texture, FrontStreet Coffee's experience shows that attention to certain details is still necessary. Now, let's start with the specific operations～

Step 1: First, make an espresso base

Many online versions directly use instant products like 3-in-1 or freeze-dried coffee, whisking directly after adding water. Due to their higher solid content, they can more easily achieve an ice cream-like texture.

However, since this creative specialty drink is primarily composed of coffee and milk, the coffee base naturally plays a key role in determining the flavor direction of the entire beverage. Therefore, compared to relatively single-flavored instant products, FrontStreet Coffee prefers freshly ground and extracted espresso, which can make the foam coffee's aroma richer.

Commercial espresso beans are mainly divided into two categories: one is medium to dark roast beans specifically designed for crema extraction and providing a rich texture, such as FrontStreet Coffee's Mamba Italian blend coffee, which is quite suitable for making various milk coffees or for those who dislike acidity; the other is medium roast beans that highlight certain floral and fruit notes, which can be either blends or SOE (Single Origin Espresso). FrontStreet Coffee's Strawberry Candy espresso belongs to the former category, while directly using single-origin beans to extract espresso falls into the latter category. Here, we use medium-roasted FrontStreet Coffee's Colombian Sidra as a demonstration, where the extracted espresso can perfectly express flavors of grapes, dried fruit, and blueberry candy.

Step 2: Whip the coffee into a dense, foamy texture

After making the coffee, we come to the most critical and error-prone step—whipping the coffee foam. The most common problem people encounter is that no matter how they whisk, the coffee liquid cannot thicken, shows no signs of hardening, and the foam is very rough. After browsing through countless online tutorials, FrontStreet Coffee has compiled three techniques that can easily help us whip espresso into a smooth, fine bubble layer.

1. To achieve a milk cap-like texture, the water content in the espresso should not be too high. Here, FrontStreet Coffee improves the espresso concentration by cutting off the tail end, making it into a Ristretto. FrontStreet Coffee's original parameters for Sidra were 20g of coffee powder extracted for 32 seconds to yield 40g of liquid weight. Here, we change it to extracting 30g of coffee in 26 seconds. (If you're using a moka pot, just wait until the coffee liquid reaches 1/4 of the upper pot before turning off the heat.)

Left side is espresso, right side is Ristretto

2. Although espresso turns into large bubbles under the rapid operation of the whisk, due to poor stability, it quickly returns to a liquid state. We can increase the amount of sugar to "stabilize" the foam group. FrontStreet Coffee uses 10g of fine sugar here.

3. Another situation is that the freshly extracted espresso is too hot, making it difficult to foam during whisking. In this case, you might as well add ice directly to cool it down quickly.

The conventional operation is to pour espresso into a cup, add 10-15g of fine sugar, and then whisk directly. However, FrontStreet Coffee first adds 30g of ice cubes here, gently shakes it a few times to quickly cool down the espresso.

Wait until the coffee liquid is completely cool, remove the ice cubes, then start the whisk to let air mix into the liquid and form a large vortex, until it reaches a thick and smooth state, then you can stop whisking. The entire process usually lasts 2-4 minutes. When preparing a container, try to choose a taller transparent glass cup, which prevents overflow/splashing during the stirring process and makes it easy to observe the state of the coffee foam.

Step 3: Pour the coffee foam over the milk

Prepare a nice cup (200-250ml), add 60g of ice cubes and 120g of fresh milk, then without hesitation, pour the coffee foam on top. At this point, a beautiful layered gradient effect will form. While the foam is still fine and dense, take a big sip quickly.

Foam Coffee is Still Not on Our Menu!!!

Friends who have visited FrontStreet Coffee's Dongshankou store probably know that including the foam coffee we introduced today, all the specialty drinks mentioned in our articles, regardless of whether they taste good or not, are not served by FrontStreet Coffee. Because of this, many customers express regret, and some readers feel puzzled: "If you don't serve it, why write about it?"

Coffee, as an everyday beverage, is consumed by some for its energizing effect, enjoyed by others for its aroma, while some people enjoy the hands-on experience of making a cup themselves.

In FrontStreet Coffee's view, these highly individualized specialty drinks are not rare treasures; they are merely the result of deconstructing and recombining coffee with other ingredients. For most baristas, as long as they have all the ingredients ready, they can easily replicate them. However, for home brewers, equipment limitations, different extraction methods resulting in varied coffee flavors, plus unfamiliarity with parameters make imitation prone to failure. What FrontStreet Coffee does is precisely to open up new ideas for everyone through articles, allowing you to "turn the tables" and become a coffee expert yourself.

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Important Notice :

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Tel:020 38364473