How many coffee beans in one shot of espresso?

Espresso is a concentrated form of coffee that is made by forcing hot water through finely ground coffee beans under pressure. This results in a thick, syrupy coffee with a powerful flavor and aroma. But how many coffee beans actually go into making a single shot of espresso?

What is a Shot of Espresso?

A shot of espresso is generally defined as 1 fluid ounce or 30 milliliters of concentrated coffee. The standard or “normale” shot used for making most espresso-based drinks like lattes and cappuccinos contains around 7-9 grams of ground coffee.

This amount of ground coffee is the key factor that determines how many beans are used per shot. The number can vary based on the roast and grind size of the beans.

Calculating Beans per Shot

To determine how many whole coffee beans go into an average shot of espresso, we need to take into account a couple of factors:

  • The weight of whole beans vs ground beans
  • The extraction yield of espresso

Whole Bean Weight

Whole coffee beans lose approximately 75% of their weight when ground into an espresso grind. So 7 grams of ground espresso corresponds to around 28 grams of whole bean coffee. This number can vary slightly depending on the coffee variety, roast level, and grind size.

Extraction Yield

Extraction yield refers to the percentage of coffee solids that are extracted from the ground beans into the liquid espresso. For espresso, the ideal extraction yield is 18-22%. This means that for 7 grams of ground coffee, only around 1.3-1.5 grams of coffee solids are actually extracted into the shot.

Taking these two factors into account, we can estimate that on average, a single 1 ounce/30 mL shot of espresso contains:

  • 7-9 grams of ground coffee
  • 28-36 grams of whole bean coffee
  • 1.3-1.5 grams of extracted coffee solids

Espresso Bean Origins and Blends

The specific coffee beans used to produce an espresso shot can vary greatly depending on the origin, variety, processing method, and roast profile. However, there are some general guidelines for selecting optimal espresso beans:

Arabica vs Robusta

The two main species of coffee grown for commercial production are Coffea arabica (Arabica) and Coffea canephora (Robusta). Arabica beans make up the majority of specialty grade coffees and are used for most espresso blends. They produce a more balanced, aromatic espresso with greater complexity. Robusta beans have a harsher, more bitter taste but produce a thicker crema. Most espresso blends contain 10-30% Robusta to enhance the crema and provide a stronger caffeine kick.

Blend vs Single Origin

Espresso blends combine beans from different regions and sometimes different varieties to produce a complex, consistent flavor profile. However, high-quality single origin espressos allow the unique terroir and characteristics of an individual coffee farm or region to shine through. Popular single origin choices for espresso are Central/South American beans (Brazil, Guatemala, Costa Rica) and African beans (Ethiopia, Kenya, Rwanda).

Light, Medium and Dark Roasts

The majority of espresso roasts fall in the medium to dark category to produce sufficient solubility and sweetness balanced with the characteristic roast flavors. Light roasts can lack body and have more acidic bright notes that get amplified in espresso. However, a skilled roaster can produce a smooth light roasted espresso by blending different bean types and roast levels.

How Grind Size Affects Espresso Extraction

A proper espresso grind is extremely fine and powdery in texture. An optimal espresso grind allows for the hot water to extract the maximum amount of soluble compounds in the 25-30 seconds of the extraction process. The grinds should resemble moist sand that clumps together when pressed.

Here’s how different grind sizes impact espresso extraction:

  • Too fine – Causes overextraction, faster extraction time, bitter/astringent flavor
  • Too coarse – Underextraction, slower extraction time, weak/watery flavor
  • Just right – Balanced extraction, full sweetness and aromatics

The grind size must be adjusted for different types of espresso machines and the age of the roasted beans. Fresher beans require a slightly coarser grind. Conical burr grinders usually produce the most consistent espresso grind.

Standard Double Shot vs Ristretto vs Lungo

The standard single espresso shot described above is the basis for other common espresso drink styles:

Double Shot

A double shot simply contains twice the amount of coffee – approximately 14-18 grams of ground coffee yielding around 2 fluid ounces or 60 mL of espresso.

Ristretto

A ristretto is an even more concentrated espresso made with the same amount of ground coffee but half the water. It has a higher extraction yield and more intense flavor in just about 15-30 mL of liquid.

Lungo

A lungo is the opposite of a ristretto. It uses the normal 7-9 grams of ground coffee but twice the water for a weaker, more diluted espresso of up to 60 mL.

How Many Beans for Multiple Shots?

For multiple servings of espresso, the number of beans used simply scales up based on the number of shots and size of shots pulled:

Espresso Drink Coffee Beans Used
Single shot 28-36g beans
Double shot 56-72g beans
Triple shot 84-108g beans
Quad shot 112-144g beans

As you can see, making espresso at home for 4 people could easily use over 100 grams or more than 1/4 pound of whole bean coffee. High volume espresso bars go through several kilos of beans per day!

Factors That Change Dosage

Though the 7-9 gram baseline works for most recipes, some factors may require increasing or decreasing the coffee dosage per shot:

  • Bean age – Older beans lose CO2 and may need higher dose for proper extraction
  • Roast level – Light roasts have less solubility so may need higher dose
  • Blend – More robusta and darker roasts have more solubility so may need lower dose
  • Grinder – Inconsistent grind requires higher dose for proper extraction
  • Water quality – Soft water allows lower dose, hard water needs higher dose
  • Machine – Lower pressure machines need higher dose for proper extraction

A skilled barista will tweak the dose up or down by 0.5-1 gram to achieve the optimal flavor balance for a particular coffee and espresso machine setup.

Weighing Espresso Shots

To achieve consistency and quality, professional baristas weigh their ground coffee dosage for espresso using digital scales accurate to 0.1 grams. They also weigh the liquid output to verify they have achieved the target extraction yield. The expected weights are:

  • Single shot: 7-9g ground coffee in, 25-30g espresso out
  • Double shot: 14-18g ground coffee in, 50-60g espresso out

Weighing shots allows catching issues like over or under extraction and makes it possible to replicate the same flavor profile across different baristas, coffee varieties, and service volumes.

Volumetric vs Weight Dosing

Traditionally, ground coffee for espresso was dosed using volumetric measures like scoops and teaspoons. However, this leads to inconsistency since the density and weight of coffee grounds can vary. For example, 10mL of light roast ground coffee weighs much less than 10mL of dark roast.

Nowadays, weight-based dosing using digital gram scales is considered best practice for quality and consistency. Weight ratios also make it easier to scale shot sizes up or down while maintaining the optimal flavor.

Lever Espresso Machines

Manual lever espresso machines require a higher coffee dosage compared to pump driven machines. This is because they operate at lower pressure (around 6-8 bars compared to 9 bars) and rely on the barista’s technique to extract the coffee.

A good starting dose for double shot on a lever machine is 16-20g. The barista extracts to double that weight, resulting in a ratio like 1:2 or 1:3 coffee to espresso. The long lever movement produces slower preinfusion and extraction compared to modern portafilters.

Pre-Ground vs Whole Bean

Ideally, espresso is freshly ground right before extraction to preserve the aromatics and CO2 in the coffee. Pre-ground coffee packs down more densely so 7-9 grams may contain slightly more beans compared to grinding whole beans immediately before use. However, the increased surface area causes pre-ground coffee to stale quickly.

Pre-ground can work but may require adjusting the dose slightly higher. It is unlikely to produce the same quality and complexity as an equivalent dose freshly ground from whole beans.

Conclusion

While the number can vary based on many factors, a general rule of thumb is that a single 1 ounce/30 mL shot of espresso contains around 7-9 grams of finely ground coffee which corresponds to 28-36 grams or 1 ounce of whole coffee beans.

To produce consistent, balanced espresso shots, precision weighing of both the ground dose and liquid output is recommended. This allows dialing in the optimal ratio for any type of coffee and espresso machine.

So the next time you sip an exceptional espresso at your favorite cafe, keep in mind the careful art and science involved in producing that single, flavorful ounce of liquid from over 30 grams of meticulously sourced, roasted and ground coffee beans!

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