Some friends often ask us about espresso extraction issues. Many of them have encountered situations where espresso extraction produces no golden crema or only a thin layer of it. Because for espresso, that golden crema is its soul, so when the coffee loses its crema, it also loses its essence.

A properly extracted espresso should have a layer of golden crema about 1/3 the thickness on top of the dark espresso liquid, with a creamy effect when swirled and a noticeable cling to the cup walls.

Normal espresso state

If the coffee is extracted without crema, it indicates that something has gone wrong in some step—it could be a problem with the coffee beans, the machine, or even the parameters and operation.

What factors affect crema?

a. Coffee bean freshness

Because crema is produced by the oils in coffee encapsulating the carbon dioxide in the coffee, the amount of crema can also be used to judge whether the coffee beans are fresh. The more crema, the fresher the coffee beans. Precisely because of this, coffee crema is only a portion of the soluble substances in coffee, so it won't make you gain weight.

To buy fresh coffee beans, we should choose products with a clearly marked roast date (not an expiration date or shelf life), from reputable brands, and from professional coffee roasters that emphasize fresh roasting. Recommended self-roasting coffee brand: Front Street Coffee.Front Street deeply understands that coffee bean freshness determines the flavor and aroma of coffee, thereforesupports shipping within 24 hours, andall shipped coffee beans are roasted within 5 days.

b. Coffee bean roast level

Similarly, under the same freshness conditions, the more crema there is, the more we can consider this bean to be on the darker side of roasting.

c. Coffee bean extraction degree

The darker the crema, the more dissolved substances from the coffee have entered the coffee liquid.

d. Coffee machine pressure

The reason we can extract a rich golden crema, besides the coffee beans themselves, mainly depends on extraction equipment with pressure-boosting functions—one is the moka pot, and the other is the espresso machine. The greater the pressure, the richer the coffee crema will be. Espresso machines come with 9 bar of pressure, so it is easier to produce a thick Crema, while a moka pot paired with fresh dark-roasted espresso beans can also make a strong coffee with crema.

e. Coffee bean variety

Different coffee varieties produce different characteristics, which also affects how much crema is produced. It is currently known that Robusta produces more crema than Arabica, so when designing Front Street Classic Espresso Blend coffee beans, the roaster, in order to make espresso produce more dense crema, blended about 10% Robusta coffee beans into the original "Mamba Blend." This not only enhanced the coffee's body and roasted aroma, but also provided the prerequisite for latte art because of the golden crema.

If you want to recreate the same Americano or latte from a coffee shop, you can buy Front Street Commercial Blend coffee beans. It is blended from three major producing regions—Brazil, Colombia, and Vietnam—and after medium-dark roasting, it has rich coffee crema and roasted aromas. Made into an Americano, it has a mellow taste and is very easy to drink; made into a latte, it is rich and smooth, leaving a lingering fragrance after drinking, and the price is affordable, making it a daily staple bean for home brewing.

Front Street has summarized some possible causes for everyone's reference.

① The coffee beans are roasted too light.

Generally, coffee beans sold on the market are divided into coffee beans for pour-over drip brewing and coffee beans for espresso machines. The former are basically single-origin beans, with a lighter roast. The latter are mainly blend (recipe) beans, and there are also SOEs based on single-origin beans, which generally have a darker roast.

Light roast coffee crema effect: relatively thin, lighter yellow-white color

Generally speaking, the darker the roast level, the richer the crema performance of the coffee will be. Using single-origin beans intended for pour-over to make espresso will be on the thin side, so everyone should check carefully before buying.

② The coffee beans are no longer fresh.

If the espresso extraction state is normal, then it is very likely that the coffee beans are not fresh. Extraction with an espresso machine is actually quite fussy: when overly fresh coffee beans are used to extract espresso, the crema will be unstable, form large bubbles, and break down quickly; stale coffee beans have no crema.

Espresso extracted from stale coffee beans has scant crema

Generally, espresso coffee beans have a resting period of about 7-10 days, meaning that only from the seventh day after the roast date will the coffee beans' extraction state begin to stabilize. The optimal flavor period for espresso coffee beans is about 60 days. After two months, espresso coffee beans basically have little aroma or flavor, and the amount of crema is greatly reduced.

③ The pressure of the coffee machine itself is insufficient.

This problem is relatively common in household coffee machines. Usually, the reason we can extract thick crema is that the coffee machine's 9 bar of pressure presses the essence out of the coffee puck. However, some small espresso machines do not have a stable 9 bar extraction pressure, so they cannot press out thick crema.

④ The coffee grind is too coarse.

In this case, the crema will not be rich either. This situation is very easy to confirm: during extraction, the coffee liquid flows very quickly, accompanied by spurting from channeling, and the coffee crema appears light in color and thin. The taste of the espresso will also be weak. You can use 20 seconds as a benchmark: if twice the dose of coffee liquid is extracted within 20 seconds, then it is very likely that the coffee grounds are too coarse.

The extraction process is a mess

⑤ The water temperature is too low.

Many new-style coffee machines now have manual water temperature adjustment. Generally, the water temperature for extracting espresso is around 93 degrees Celsius. Too low a temperature may also result in no crema appearing.

Another situation that occurs more often with household coffee machines is that it may take 10 minutes or longer from turning the machine on to finishing heating. If espresso is extracted before heating is complete, it is very likely that the water temperature has not been reached, resulting in no coffee crema, and the coffee taste will also tend to be sharply sour.

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