Is There a Big Difference Between Single and Double Shot Espresso? Espresso Single vs Double Distinctions and Characteristics

If you want to have an espresso at a coffee shop, besides saying "I'll have an espresso," you can also say "I'll have a shot." A shot is the unit for espresso, where 1 shot of espresso means one serving of espresso, sometimes also expressed as "single espresso." If you feel that one serving of espresso is too small and not satisfying enough, you can say "double shot" when ordering, which means a double serving of espresso.

What's the Difference Between Single and Double Shot?

From a customer's perspective, single and double shots are merely different in quantity, but from a barista's perspective, this requires two different preparation methods.

If you've used an espresso machine, you'll know that the portafilter basket has a limit on coffee ground capacity. For example, if a basket's capacity is 18g, then the coffee grounds you load should be between 17-19g. Loading too much coffee grounds won't allow the portafilter to lock onto the group head; loading too little will affect extraction.

Therefore, if you want to use less coffee grounds, you must switch to a smaller capacity basket. This is the difference between extracting single and double shots.

For example, when extracting a single shot, the barista will use a single basket, load 11g of coffee grounds, and extract 30ml (22g) of espresso. When extracting a double shot, the barista will use a double basket, load 18g of coffee grounds, and extract 60ml (40g) of espresso.

However, due to the different structures of the two baskets, the extracted coffee also has differences. The double shot basket has a cylindrical structure for its volume, and after extraction, the coffee puck comes out as a neat "round almond cake."

The single shot basket, on the other hand, has an inverted cone shape. It has roughly a two-layer structure, with the upper layer having the same diameter as the double basket. But since the single basket holds half the amount of coffee grounds as the double basket, the lower layer is designed with a narrowing to maintain the same surface diameter and maximum powder layer thickness.

FrontStreet Coffee's Extraction Experiments

In FrontStreet Coffee's extraction experiments, the single basket is not as simple as being half of the double basket.

FrontStreet Coffee uses a double basket with 20g of coffee grounds as the standard, extracting 40g of coffee liquid in 27 seconds, measuring a concentration of 10.48% and calculating an extraction rate of 21.72%.

Using a single basket with 10g of coffee grounds as the standard, extracting 20g of coffee liquid, the flow rate is relatively faster, taking 22 seconds, measuring a concentration of 8.83% and calculating an extraction rate of 18.38%. The difference between the two is significant.

To make the output from the single basket approach that of the double basket, you can only adjust by grinding finer or increasing the amount of coffee grounds. Adjusting the grind for output is not practical for a coffee shop, and increasing the amount of coffee grounds will increase costs and uncertainty.

FrontStreet Coffee has experimented and found that the amount needs to be increased to 12.5g for the concentration to approach the data from the double basket.

Why Such a Big Difference?

This all comes down to structure. The double shot basket has a straight cylindrical structure, which means that whether tamping or pressurized extraction, the force applied to each part is uniform, resulting in more even extraction.

The single basket, in order to maintain a uniform diameter (to fit the group head) while ensuring the powder layer thickness, sacrifices the bottom structure. This means that whether tamping or pressure extraction, the pressure around the perimeter is always higher than the pressure at the center at the same level. To translate, when tamping, the perimeter will be denser than the center. During extraction, in the upper layer, water permeates faster at the center than around the perimeter, but in the lower layer, water from around the perimeter will converge to the center, causing uneven extraction, and in severe cases, channeling effects.

How to Make a Standard Espresso

Next, FrontStreet Coffee will demonstrate how to make a standard espresso using their store's standard "Sunflower · Warm Sunshine Blend Espresso Beans" with their usual double basket. Those who want to learn should take out their notebooks and take notes!

First, FrontStreet Coffee uses a double basket capacity, with about 18-20g of coffee grounds. FrontStreet Coffee uses an extraction ratio of 1:2, meaning 20g of coffee grounds to extract 40g of coffee liquid; if you use 18g of coffee grounds, it corresponds to 36g of espresso liquid. The time is related to the flow rate of the coffee grounds, and generally, a single extraction duration is controlled between 20-35 seconds, because within 20 seconds the coffee taste tends to be thin, while exceeding 35 seconds easily leads to over-extraction and bitter flavors. Most of FrontStreet Coffee's espressos are in the range of 28-30 seconds.

Before extraction, you need to first dry the basket, turn on the grinder, grind a double serving of coffee grounds, place it on an electronic scale for adjustments to reach 20g. Then use a distributor to level the coffee grounds, and with the tamper, apply vertical downward pressure to compact the coffee puck, ensuring more stable coffee extraction.

Then turn on the extraction switch and let water flow for 1-2 seconds to wet the group head, while also washing away any coffee grounds stuck above. Place an electronic scale under the cup that will catch the espresso, and zero it, placing it under the group head during extraction.

Gently lock the portafilter onto the group head and start the extraction by pulling down the extraction switch. Observe the changes in the extracted liquid. When the electronic scale shows 40g of coffee liquid extracted, at around 30 seconds, pull down the extraction switch. The extraction parameters will have subtle changes based on daily air humidity and coffee bean conditions, so you need to adjust the amount of coffee grounds, grind setting, and amount of extracted coffee liquid up or down.

How to Enjoy Espresso

The extracted espresso can be enjoyed directly, paired with a glass of water to rinse the palate, allowing you to taste the rich crema and the mellow texture of the underlying coffee liquid. If you can't accept the strong bitterness, you can also add water or milk according to your preference to dilute and soften the intense flavor.

When tasting a freshly extracted espresso, FrontStreet Coffee first smells the coffee's aroma. This coffee carries rich aromas of whiskey, vanilla, nuts, and cream. It can be drunk directly or with added sugar, milk, or other accompaniments. Using a prepared metal spoon, gently stir the coffee liquid to blend. The first sip tastes the rich crema - full and mellow chocolate aroma. Then take a larger sip to feel the warm coffee liquid along with the crema entering your mouth, as well as the rich flavors of nutty cookies, chocolate, berries, and wine. Halfway through, take a sip of water to experience the sweet aftertaste in your mouth. The entire experience is rich and highly layered, leaving an endless aftertaste.

Important Notice :

前街咖啡 FrontStreet Coffee has moved to new addredd:

FrontStreet Coffee Address: 315,Donghua East Road,GuangZhou

Tel:020 38364473