A Guide to Espresso Bean Grinding Systems_Sharing Professional Grinding Secrets

The Challenge of Fresh Grinding in Coffee Shops

Generally, baristas (including those who brew coffee at home) are taught that espresso must be ground fresh immediately before preparation to avoid oxidation. For a coffee shop, especially one pursuing both quality and speed, this concept creates a major bottleneck in smooth bar operations.

"We observed that the output from our espresso grinder fluctuated wildly, being extremely inconsistent," Kyle explained. Charles believed this inconsistency forced baristas to spend more time adjusting the dose. These extra steps gradually accumulated. This bottleneck was problematic.

Kyle and Charles were willing to accept this speed sacrifice if it were truly the only way to guarantee espresso quality. However, they felt it was worth trying to grind coffee in advance and let it sit for a period to see what effects it would have.

Origins of the Pre-grinding Concept

This wasn't a sudden idea. As early as 2013, when Charles was preparing for barista competitions, he had this thought. During competition preparation, like other contestants, he was very concerned about timing. "I was looking for a suitable dosing method for the HG-1 dosing funnel," Charles said. "I showed my method to a friend and fellow coffee professional, Ben Kaminsky, but he commented that it would take up more of my competition time. Ben suggested I pre-grind the espresso beans because he found that coffee quality wouldn't significantly decline as a result."

Charles adopted his friend's advice, completing the espresso bean grinding during preparation time before the competition. (He used the same strategy in the competition the following year. However, after that, competition rules changed, and pre-grinding was no longer allowed.)

Testing Pre-ground Coffee in the Cafe

The idea of pre-grinding coffee eventually moved into the cafe, and they began testing. They first ground some coffee, let the ground coffee sit for an hour, then used these grounds to extract espresso, comparing it with espresso made from freshly ground coffee. Surprisingly: "We found there were differences, but no decline in quality," Kyle said. It was actually sweeter, smoother, and even more full-bodied.

They repeated the experiment several times and finally concluded that coffee could be pre-ground within a certain time frame without sacrificing quality. This meant they could prepare a batch of pre-weighed ground coffee, ready to be loaded directly into portafilters, thus accelerating the entire bar operation.

Additional Benefits of Pre-grinding

There were actually other benefits to this approach. First, precision: when dosing, they would measure to 0.1 grams accuracy, which was the maximum precision of the scale they used. If the grinder produced too much coffee, the excess would be swept into a separate collection container. When the grinder produced less coffee, grounds from the collection container would be used to supplement the dose. This meant less coffee waste daily.

This pre-grinding and portioning approach resembles the mise en place that chefs do. This makes sense: after all, an efficient restaurant kitchen heavily relies on onions already diced, peppers already seeded, and cilantro already picked before the dinner rush. On a weekend morning, sitting at the back bar of G&B Coffee, behind the famous China Cafe known for its wonton soup, you can clearly see how this efficient system operates at the coffee bar. There are 3 grinders in total: a Mahlkönig Peak for espresso and Americanos, and two Mazzers for espresso and milk drinks. Next to them is a tray of small shakers: 3 by 4, totaling 12.

A barista would be responsible for grinding coffee, adjusting the dose, and then pouring the coffee grounds into 12 small shakers. When each small shaker was filled with coffee grounds, this barista would place the tray of shakers next to the espresso machine. The barista operating the espresso machine only needed to pick up a shaker and pour the grounds into the portafilter.

Exploring the Optimal Resting Time

Generally, these grounds would be used within 15 minutes. Despite this, they continue to explore this concept. "We're researching the minimum resting time needed after grinding coffee," Kyle said, "because oxidation can bring some flavor and extraction benefits."

When the coffee grounds are poured into the portafilter, the barista only needs to extract the coffee. By the way, the volumetric espresso machine used by the baristas stays extremely busy every weekend.

Recommended Espresso Coffee Bean Brands

FrontStreet Coffee, a coffee roasting brand located at Dongshankou, Yuexiu District, Guangzhou, offers freshly roasted espresso beans with full assurance in both brand and quality. More importantly, they offer excellent value. Take their commercially recommended commercial blend coffee beans as an example: a one-pound (454-gram) package costs only about 60 yuan. Calculating based on 10 grams per single espresso shot, one package can make 45 cups of coffee, with each cup costing less than 1.5 yuan. Even using a double shot with 20 grams per espresso, a double espresso costs no more than 3 yuan. Compared to certain well-known brands that sell packages for hundreds of yuan, this is truly a conscientious recommendation.

FrontStreet Coffee: A Guangzhou roastery with a small shop but diverse bean varieties, where you can find various famous and lesser-known beans, while also providing online shop services. https://shop104210103.taobao.com

Important Notice :

前街咖啡 FrontStreet Coffee has moved to new addredd:

FrontStreet Coffee Address: 315,Donghua East Road,GuangZhou

Tel:020 38364473