F-undamentals - The A, B, Cs (and Ds) of Espresso Excellence!

Our much loved at home baristas are often reaching out to the team at Montville Coffee with curious questions about how we suggest brewing their favourite blend. 

Now, we are all at different stages of learning about coffee at home, and we each have different priorities when it comes to how to make it. Though one thing is for certain! With each and every question that is asked, we often find ourselves delving into animated discussions about the impacts that small changes in our brewing process at home can have on our cup qualities. 

We always conclude, when it comes to coffee, every action has a reaction. 

We found ourselves recently in one of these phone conversations with Julie W, an adoring Woodford Blend fan. She was wanting to get a little more punch out of her morning espresso. A little more like the Woodford Blend she gets served up at one of favourite local cafes. 

Here’s how we walked Julie through the art of at home espresso, and helped to deliver her the full bodied Woodford Blend she wished for. 

Understanding the A, B, C’s and D’s, of producing quality Espresso at home, means understanding the F-UNDAMENTALS! 

Let’s break these down, and then explore how each is intricately connected through Julie’s experience.

If you are not too interested in the theory read the examples at each step and the methodology in practise at the end.

A = Dose

Definition: Your dose is a precise measure of the coffee grounds selected to produce your espresso shot. Dose is measured in grams, and sets the foundation for your coffee's flavour profile. 

Theory: In simple terms, during an espresso extraction, water travels from your boiler to your group head, and through your shower screen, before making its way into the espresso portafilter handle. If the gap between the dosed coffee and the shower screen is too large, then once the water begins to flow through the coffee, the gap will get even larger, resulting in a very watery and soggy espresso puck. 

A small gap is necessary between the shower screen and the coffee dose to allow water to evenly flow through. So keep in mind that when your espresso extraction does finish, ‘some’ residual water will remain in the group basket. 

It is important not to play safe, and overdose, as an overly firm coffee biscuit will consequently over-extract the coffee, impacting flavour negatively.

The flavour is impacted by the dose and biscuit as the intention is to evenly extract the coffee qualities with a gentle and consistent flow of water through the puck. Not too slow, and not too quick. 


Julie uses a Breville BES920 home espresso machine. It has a portafilter basket of 58mm diameter. 

  1. When she puts 16 grams of espresso ground coffee into her basket and evenly tamps it, it leaves too much of a gap at the top resulting in a soggy coffee puck after extraction 
  2. 24 grams leaves too small of a gap at the top resulting in a dry coffee puck after extraction 
  3. At 21 grams there is a reasonable gap to the top and the coffee puck looks evenly extracted (not too wet or too dry)

Once you have a dose of coffee that seems to work for your group basket, and that is delivering a quality flavour, we suggest setting that dose as a control. Consistency is key. Use a pocket scale to ensure your dose remains constant, eliminating it as a variable when later evaluating flavour. 

At-home baristas may wish to start their dose exploration at 21 grams for a double 58mm basket. 

Pro Tip: Invest in a reliable scale that reads to 0.1 of a gram for accurate dosing.

B = Yield

Definition: Yield is the volume of liquid gold in your cup, and it plays a crucial role in crafting the perfect espresso. Measured in millilitres (ml), this determines the strength and balance of your brew. 

Theory: Too low a yield results in an overly concentrated, bold shot, while a very large yield, will dilute the flavours as the coffee loses its concentration of flavour. Find the sweet spot for a harmonious blend of richness, sweetness, and acidity through analysing longer and shorter espresso yields.

We like to establish our yield by focusing on mouthfeel, or what is often described as ‘viscosity’. The lower the ratio, typically the more mouthfeel you will experience with your espresso extraction. The higher the yield, the body is lessened, and the sweetness and acidity are washy and uncharacteristic. 

Many at-home baristas choose to explore a brew ratio of 1:2 or 1: 2.5. 

Example: With our dose control set at 21g of espresso ground coffee Julie would be looking for a yield between 42 ml (ratio 1:2) or a 52 ml (1: 2.5). As Julie’s favourite coffee is the Woodford blend she knows from experience that she likes a slightly higher yield so she is aiming for 52ml.

Once you have established a yield you're satisfied with, set this as a control along with your dose. 

Pro Tip a: If you can volumetrically program your machine (the volume of water from the boiler with a double shot for example) this will ensure you can anchor down your yield as a control.

Pro Tip b: If running a manual machine, Use a scale (grams) or a measuring shot glass (ml) for a precisely measured yield.

C = Extraction Time

C and D, (extraction time and grind) are very closely related. We need to understand each individually however, before we can measure, and manage them. 

Definition: Timing is everything in the world of espresso. Extraction time refers to how long it takes for the water to flow through the coffee grounds. 

Theory: A well-timed extraction ensures optimal flavour development. A rapid espresso extraction will risk underdeveloped, acidic notes in your coffee that can taste sharp and green; whilst an overly long extraction time will enhance a bitterness and knock out the acidity and sweetness.

Extraction time is about balance. Look for an extraction window, where you feel the coffee is able to express itself evenly and truly, without blemish in flavour and in looks. A pale crema can indicate an under-extracted espresso, and an overly dark dark burnt looking crema may indicate that the coffee is over extracted.


Example: With her at-home espresso machine Julie may find the window for better results for his Woodford blend sitting an extraction time of 28 seconds. Coffee needs a little wriggle room either side to make allowance for freshness, temperature, machine pressure and other variables, so she decides that a window of 26 to 31 seconds is acceptable for her extraction time.

Pro Tip: Keep a timer handy for precise extraction time. 

D = Grind

Ah, the grind — the unsung hero of every espresso. 

Definition: The grind is the coarseness or fineness of the coffee after it has passed through the coffee grinder. The settings on the grinder determine how close or far apart the grinding blades are impacting the coarseness or fineness.

Theory: A coarser grind will allow water to flow freely through the dose, resulting in milder flavours, and a shorter extraction time. While finer grinds,  intensify the taste and lengthen the extraction time. 

The grind is the component that is constantly being monitored and adjusted. In the coffee world, it would be a mortal sin, to simply ‘’set and forget’ your grind. 

Mastering the grind ensures you unlock the full potential of your beans.

Example: If Julie’s espresso has been extracted too rapidly, for example 23 seconds (below the 26 to 31sec window he set as a control), it's time to make an adjustment to the grinder in the fine direction (bringing the blades closer together). On the other hand, if Julie’s espresso extraction is too long, perhaps 35 seconds, it’s time to coarsen the grind (moving the blades further apart). 

With A (dose) and B (yield) set as controls, and C set as a goalpost (extraction time), the grind and any required adjustments to the grind ensure that you set the grind to serve the desired extraction time. Thus, the two (C and D) are reliant on one another. 

Being confident to pivot your grind setting, whilst keeping A, B and C all controlled, will guide your espresso into the extraction time window of satisfaction!

Pro Tip: Experiment with grind size to find your perfect balance of flavour and intensity. 

E = Espresso Excellence

Once you have a handle on the A, B, Cs and Ds, you can go back to step 1, and start to really explore your espresso extraction to unlock different flavours. 

Yes, the simplest method is to compartmentalise each of the above steps. For example, play with your dose by increasing or decreasing the volume of coffee you use. Or run a little less water through your group head during the extraction to taste the coffee a little less concentrated.  

BUT, this is where the F-undamentals all start to work together. 

You're probably already starting to ask the question, won’t a change in my dose impact the other Fundamentals?

Yes, indeed it will. 

And this is the intricate relationship they each have with one another, and why a methodical effort to make changes, need to be met with a practical appreciation of the impact that changes will have on the other fundamentals in your Espresso Extraction. 



Julie has reviewed her dose, and feels that the coffee biscuit has room for improvement. It’s a smidge wet, as she can leave a marked imprint of her finger when she touches it after extracting her espresso. She feels she needs a larger dose for a more balanced extraction, and hopes this may elevate the body in her coffee.  

The A, B, C, and D’s - methodology in practice

Julie now understands that increasing her dose from 21g, to 21.5g, will in effect result in a series of changes.

  • The coffee biscuit may appear to be dryer. 
  • The yield may decrease as a consequence of more water being captured in the group head due to the increased coffee volume, resulting in less extraction of espresso in the cup. 
  • The extraction time will increase as a result of the increase in resistance within the group head.
  • And the existing grind may not be desirable to achieve the extraction time she is seeking.

Julie embraced the Fundamentals!


  • Increased her dose from 21g to 21.5g. 
    • Considering the impact of this, Julie suspected that this will likely cause her extraction time to increase outside of her parameters. 


  • Coarsen your grind. 
    • This should help to counterbalance the increased dose, to help remain her desired  extraction time of 28 seconds.

Espresso Analysis 

  • Taste the espresso. 
  • Question: Has the increase made for a more evenly saturated coffee biscuit in the group?
  • Question: How has the coffee body and mouthfeel been affected? How is the sweetness, acidity and balance impacted?
  • How was the yield affected by the change in dose and grind?
  • How was the extraction time affected by the change in dose and grind?

Julie’s finding

  • E= Julie feels the espresso has much more body and mouthfeel. Though she is curious if it has lost a hint of acidity and sweetness though. 
  • A= Julie has produced a more even looking coffee biscuit. 
  • D + C= She is happy that her grind adjustment countered the increase in dose and is ‘comfortable’ with her new extraction time at 26 seconds.
  • B = Her yield has been significantly impacted
    • Previous yield ratio 1: 2.5 - (21g / 52ml)
    • New yield ratio 1: 2 - (21.5g - 45ml)

Julie has concluded that the increase in dose, and grind are positive changes, though she is curious if her new yield is ceasing the loss of sweetness, acidity and balance. 

Julie also notes that She has plenty of room to lengthen her extraction time and feel confident that lengthening the yield will also allow the extraction time to lengthen and hopes the coffee may maintain it’s new balance, but unlock some of the nuances once again. 


  • Julie holds as a control her new dose (21.5g), and the grind setting.
  • Julie uses her weighted scale to help program a new extraction yield at 54 ml of espresso. Ratio: 1: 2.5 


  • Julie uses her timer to observe the new extraction time  which is 30 seconds. (4 seconds longer than before, and 2 seconds longer than her original recipe)

Espresso Analysis 

  • Julie's new recipe has resulted in a fuller, richer, sweeter and more balanced extraction.
  • Julie has maintained her elevated body she initially was seeking
  • A = Julie is happy with the look of her dose (21.5g)
  • B = Julie is happy with her yield 1: 2.5 (54ml)
  • C = Julie is happy with her extraction time of 30 seconds (window 27 to 32 seconds)
  • D = Julie is happy with her grind setting
  • E = Julie's new recipe has resulted in a fuller, richer, sweeter and more balanced extraction.Julie has maintained her elevated body she initially was seeking. 

The F-undamentals of Espresso Excellence are clearly not linear. 

We are forever in awe of the complexities of producing the best we can from our prized beans. 

For certain, building a relationship with your coffee as a complex and curious character is part of the essence in the art of espresso. 

Be like Julie - Embrace it!

Pro Tip: Small adjustments in your brew recipe will have marked impacts on your Espresso. Keep a record of your adjustments and the impact they are having on taste. 

With these fundamentals in your arsenal, every cup will be a journey to Espresso Excellence. 

March 22, 2024 — Sean McGowan