Latte coffee looks simple, but achieving a mellow, balanced cup is not easy. From a barista's perspective, this article systematically sorts out the techniques for making iced lattes, including the choice of coffee bean roast level, the espresso extraction formula, the control of the milk-to-coffee ratio, and the causes and solutions for common problems such as too bitter, too weak, or both bitter and weak. At the same time, combined with Front Street brand's multiple blend beans and SOE single-origin beans, it gives recommendations for different flavor preferences, helping coffee lovers consistently produce a delicious iced latte in daily preparation.

Do you still remember the moment you first tasted a latte? Many friends may no longer recall it clearly, but Front Street is still deeply impressed—first attracted by the exquisite latte art, then taking a sip and feeling the slight sweetness and bitter notes brought by the crema; with the second sip, the original strong bitterness turned into roundness and smoothness, interwoven with the sweetness of hot milk, achieving just the right balance in the mouth, and after swallowing, it still left a creamy chocolate-like finish.

Just as the Western proverb says, there are a thousand Hamlets in a thousand people's eyes, and the same is true of coffee. For a delicious latte, everyone may have their own standard of judgment: some prefer it generous in portion, some value its richness and balance, and others are drawn to those beautiful latte art designs.

However, when it comes to a bad-tasting latte, everyone's feelings are surprisingly consistent—either the coffee is so bitter it is hard to swallow, or the taste is too weak and unappealing like water, or both situations appear at the same time, both bitter and weak. What exactly causes this?

The formulation approach for latte coffee

When making latte coffee, it is recommended to give priority to medium-dark roasted blend beans or SOE single-origin beans, because such beans have richer caramel-like aromas and a fuller flavor, can create a clear contrast with sweet milk, and bring a lasting sweet aftertaste. If you seek stability and value for money, you can choose Front Street Classic Blend and Front Street Dark Cocoa Base Blend; they not only have rich crema, but also carry an intense aroma like butter and roasted chestnuts;

If you prefer the unique flavor of single-origin beans, Front Street Queen Manor SOE and Front Street Sumatra · Front Street PWN Golden Mandheling SOE are recommended. After extraction, they can present strong caramel and chocolate tones, making the contrast with fresh milk even more prominent;

If you want the coffee flavor to be a bit fresher, you can choose medium or medium-light roasted beans, such as Front Street Strawberry Candy Espresso and Front Street Huakui SOE, which are specifically roast-adjusted for espresso in Front Street's bean list. Both can extract a cup of espresso with rich fruity flavor, and making a latte with them paired with purified milk has a distinctive taste.

Today, taking Front Street Classic Blend as an example, we first apply the conventional espresso formula: a coffee-to-liquid ratio of 1:2, that is, 1 gram of coffee grounds yields about 2 grams of coffee liquid, with the time controlled between 25 and 35 seconds. Taking Front Street's actual operation as an example, use a double basket filled with 20 grams of coffee grounds, extract 40 grams of espresso, keep the duration at 27 to 33 seconds, and ensure there are no abnormalities throughout the extraction process (channeling, splashing, unstable flow rate).

If making a hot latte, Front Street will use a 1:5.5 ratio, pour 220 milliliters of fresh milk into the milk pitcher, steam it to 55 to 65°C, while forming a 0.3 to 0.5 centimeter thick milk foam, and finally mix it evenly with the espresso, pour it into a ceramic cup, and draw a neat pattern.

When making an iced latte, we first place 3 ice cubes at the bottom, control the coffee-to-milk ratio at 1:5, first pour in 200 grams of fresh milk, then drizzle on 40 grams of coffee liquid, to preserve a beautiful layered effect.

According to Front Street's experience, as long as the coffee beans and milk are reasonably paired, and espresso extraction and milk ratio are stably controlled, making a delicious latte is actually not complicated. In other words, if the latte made does not taste right, the problem must lie in the above steps. Below we analyze them one by one.

First, why does a latte taste bitter?

Everyone knows that, without adding sugar, a latte is the least bitter among all fancy coffees, because it adds a large amount of milk, so the coffee flavor usually is not too prominent. When you do taste obvious bitterness, it means the problem is most likely in the espresso—either the coffee beans are roasted too dark, or the extraction parameters are not right.

Regarding the former, unless what you bought is extremely dark roasted beans so dark they are oily, in order to retain more of the coffee's own flavor, most common espresso recipes on the market use medium-dark to dark roasting, at most just reaching the start of second crack when discharged. The espresso made from such products usually has rich crema, slight acidity, and moderate bitterness and sweetness, and after blending with milk it forms a compatible mouthfeel, without letting either side stand out too much.

Generally speaking, the "culprit" that makes a latte bitter is often espresso extraction, most commonly over-extraction caused by too slow a flow rate (extracting for more than 35 seconds according to the above formula), channeling, splashing of the liquid stream, and so on.

A customer once told Front Street that the lattes they usually made tasted quite good, but suddenly one day the taste became especially bitter and not aromatic. The coffee beans were still within their tasting period, and the extraction parameters and ratio were the same as usual, but they just could not find the reason. Finally, after careful questioning, it turned out that the knocked-out puck had already been perforated, indicating that channeling had occurred during extraction, possibly because coffee grounds clumped and caused over-extraction and bitterness. The corresponding solution is to adjust the grind coarser, or use external force to break up the clumped coffee grounds.

What should you do if the latte tastes too watery or too weak?

From a barista's perspective, the richness of a latte depends on both milk and espresso. For a latte, milk, which makes up the largest proportion, is naturally a key part. If you want the coffee to be rich and mellow, it is recommended to give priority to whole fresh milk, because compared with shelf-stable milk or skim milk, whole milk has a higher milk fat content, and after steaming, the foam layer is denser and more stable, providing the coffee with a fuller mouthfeel.

In fact, besides milk quality issues, insufficient espresso extraction can also make a latte watery or weak, and this kind of situation usually appears with SOE. Front Street once used the lighter-roasted Huakui 8.0 to make an SOE latte. Although the milk ratio had already been reduced, the resulting taste was still extremely thin, just like a cup of hot milk with a hint of citrus and caramel aroma, clearly because the roast level was too light and caused under-extraction.

So when we use single-origin coffee beans with a mainly fruity profile to make large-volume lattes, it is best to choose the corresponding SOE version, so that it is less likely to "fail."

Why does a latte taste both bitter and weak?

This situation is usually the opposite of the previous SOE case, often because the coffee beans are roasted on the darker side, and the espresso overall shows a heavy and roasty profile, with the later-stage substances mainly bitter, woody, and off-flavored. If a ratio with a higher extraction yield is used, the espresso is very likely to become over-extracted.

For example, some friends like to use 18 grams of grounds to extract 40 grams of coffee liquid. At this time, the grounds-to-liquid ratio is about 1:2.22. On the one hand, it makes the coffee bitter and astringent; on the other hand, the increased liquid weight also means more water content, and the coffee concentration decreases accordingly, so the latte made is naturally both bitter and weak.

If you feel that the latte you make also has this contradictory mouthfeel, you might try reducing the espresso extraction amount a little, for example by reducing the liquid weight by 5 grams, to increase the concentration. This not only avoids over-extraction, but also makes the latte's mouthfeel fuller.

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