Basics in Dialling to Taste

How to Dial In Espresso: The Basics 

A few notes before we begin:

1. The guide below is just one approach to dialing in espresso. There are many variations and shot profiles. If you’re just starting out, this step-by-step method is a simple way to get familiar with the basic principles of espresso extraction.
2. The 1:2 in 30 seconds “rule” is a guideline, not a strict rule. Don’t stress about hitting it exactly - letting go of rigid parameters will make dialing in your next coffee much easier.

3. We can divide the brew phases into

   Chamber fill > Soak/"Pre-infusion" > Percolation > Shot end

4. This guide assumes that you are brewing with water that tastes good

When dialling in a shot, there are three main variables you can manipulate to affect the taste of your espresso.

• Dose - grams of coffee in
• Brew ratio - espresso yield relative to dose (e.g., 20g in → 40g out = 1:2)
• Grind size / shot time

Index

Step 1: Lock in Your Dose

Step 2: Quick Grind Size Adjustment

Step 3: Adjust Brew Ratio to Taste

Step 4: Optimising Extraction via Grind Size 

Brew temperature

Help! My shot tastes bad no matter what I do!

I’ve mastered this technique. What next? 

Step 1: Lock in Your Dose

Choose a dose that is appropriate for your basket. This will determine your puck bed depth.

• Underdosing can create a soupy puck or a puck that is too thin to maintain its integrity during the shot. While a soupy puck isn’t necessarily a problem, a too-thin puck can fracture under pressure, making even extraction difficult.
• Overdosing may cause the puck to touch the shower screen, leading to uneven wetting. Thicker pucks are also harder to extract fully, particularly with lighter roasts. If your shots taste sour despite longer extraction, try reducing the dose by ~2g.

Note:

1. The Argos ships with an 18g basket - 18g of coffee is a good place to start and adjust from here as necessary.
2. Different coffees and grind sizes take up different volumes. For example, 18g of one coffee may fit perfectly in your basket, while 18g of another coffee may not fit at all. This is normal, so rated basket doses are just a guide.
3. Changing Dose will also affect shot time, but for simplicity's sake, lets lock in your dose first and adjust shot time via grind size.

Step 2: Quick Grind Size Adjustment

After setting your dose, adjust grind size to achieve a shot where

• the puck can be fully saturated during the fill-phase via boiler pressure (use the piston to add extra pressure to wet the puck if your grind is too fine)
• there are not too many drips into the cup before you pull the lever to start the percolation phase

Finer grind → slower wetting, more puck resistance, fewer drips into the cup during the fill stage

Coarser grind → faster, more even wetting of the puck. Faster flow, more drips into the cup during the fill phase

Step 3: Adjust Brew Ratio to Taste

Brew ratio is one variable you can manipulate that can result in big taste changes in your espresso, sometimes more so than grind setting.

Generally speaking, if your espresso is tasting

• Too sour - Increase yield (eg. instead of 18g in 36g out, try 18g in 40g out)
• Too bitter - Decrease yield
• Bitter and Sour? Your extraction may be uneven; focus on puck prep.

You can use the below starting points depending on the roast lever of your coffee:

In Spring Configuration or Direct configuration + v1 piston linkage, the full swept volume of the Argos' piston with a full brew chamber should net you around 43g of espresso in the cup, not including the espresso that might have dripped into the cup during the pre-infusion stage.

In Batch 2 machines with the longer throw V2 Piston Linkage, this swept volume in Direct configuration increases and should net you about 50g espresso out in the cup. Batch 1 customers who have installed this v2 linkage will see similar increases in output. Note that this upgrade will not effect output in Spring Config.

If you want less espresso in the cup:

• when you're about to reach target espresso weight, halt the movement of the lever to stop/slow the flow of espresso out, then remove your cup. Empty the rest of the espresso into the drip tray or catch cup
• practice filling the chamber only partially by not raising the piston all the way during the fill

If you want more coffee in the cup:

• allow more espresso to drip through during fill/pre-infusion to supplement your usual swept volume
• perform a "Fellini" move, in which you first allow the piston to lower, pushing espresso out through the puck, then lift the piston all the way again to refill the brew chamber and commence the second part of the shot. The bleed-valve in the Argos' piston protects the puck from getting unseated during the manoeuvre.

To help you decide if you need to increase or decrease your espresso yield to attain the taste results you want, check out Barista Hustle’s Espresso Compass.

Step 4: Optimising Extraction via Grind Size 

Once you’ve found your coffee's ideal brew ratio, we can further adjust grind setting to maximize extraction potential.  In my experience, this step is best guided by taste instead of looking at output variables such as shot time. With this guide's dialling process, we start by grinding a tad finer, taste the results, then try going finer again until you get to where you want to be.

A general rule of thumb is that finer grounds can expose more coffee solubles, thus increasing flavor complexity, body, and texture.

The Espresso Compass linked above is incredibly helpful here. In this step, you want to look at the “Extract More/Less” axis on the graph, and adjust your grind based on what you're tasting, and what changes you wish to see.

This generally presents itself as a drop-off in flavour, and shots starting to taste 'under' extracted. You might even see a counter-inuitive increase in flow rate, because water has forced its way through a channel with high flow, while the rest of the puck remains underextracted.

Congratulations! You’ve dialled in your shot - enjoy that espresso.

A Note on Brew temperature

Manipulating brew temperature generally has fairly small effects on the flavour of espresso, especially in comparison to other variables like brew ratio.

However, if your shots are tasting a bit too harsh or bitter, try lowering brew temperature by 2°C

If your shots are tasting a bit too sour and adjusting other variables isn't quite getting you there, try try increasing brew temperature by 2°C.

Help! My shot tastes bad no matter what I do!

If your espresso consistently tastes bad to you no matter how much you dial in, your beans could be the culprit, not your technique. Try cupping the beans to get a broader sense of their overall flavor profile. This can give you a clearer idea of what to expect from your espresso.

If the beans taste overly sour or bitter to you during cupping, it’s likely those same qualities will carry through to the shot, no matter how well you dial in.

Check out this video by James Hoffmann on how to cup coffee at home.

I’ve mastered this technique - what next?

One you’ve mastered the basics of dose, ratio, and shot time, you’re ready to take a deeper look at the many variables one can manipulate to improve the quality of extraction and the resultant cup.

Click here for an article on how to manipulate brew variables on the Argos specifically.

Additionally, here is Shotwell’s guide on Preferential Extraction - it breaks down how manipulating brew variables can influence espresso flavour.