Wednesday 21 February 2024

Dialing in Coffee - Dose, ratio, Grind size & The Time Factor.

If you want good tasting espresso for whatever coffee drink you're making
dialing in your coffee is absolutely crucial . The aim is to get a good brew recipe.
This post's focus is mainly on the time factor.
You need to do this whenever you have a new bag of beans. 
(even if you're using the same coffee from the same roaster as last time).
Getting a good coffee is a bit like getting a good golf swing. 
Repeat, repeat, repeat. Try to reduce variables. get consistency.

The main three parts to a recipe are:
1. Grind size
2. Contact Time (sour - sweet - bitter)
3. Ratio (the amt of coffee to the amt of water)
(Pressure + temperature are also impt)

My simplest coffee machine is a Breville Bambino.
I think this is a great machine to do the initial dialing in, since its simplicity
eliminates lots of variables.
The extraction temp (PID) is set to 93C.
The higher the temp, the more extraction potential.
Extraction pressure is set to 9 bars.
The higher the pressure, the more extraction potential.
(I understand the machine applies a low pressure preinfusion at the start, 
and this then ramps up to 9 bars).
The only thing you can change is the amount of water (volumetric shot control).

Pressing the start button on the coffee machine is the crucial moment to measure/record.
If your coffee machine has a built in timer which activates the moment you 
press the start button, that's perfect. 
The Bambino doesn't have this, but my scales do.
You can also just use you phone's timer, or something like the Acaia Lunar Scales which
start timing the moment the first drop of coffee hits the glass.
Another scale to use is the Timemore black mirror.

Both these scales are OK though not perfect for measuring time, as what we really want is to
start measuring time from when the button is pressed, not when the first drip of coffee hits the cup.
A work around to fix this is just to count 6 sec (for the pre-infusion) then add whatever the scale timer reads to give you your final time.

The Contact Time is impt. As water touches the coffee and extraction occurs 
the coffee extracted goes from sour, to sweet, to bitter.
All coffee extracts in this order.


I tend to use 18 gram of coffee.
I am looking for 36 gram of liquid out because I'm 
working on a ratio of one to two.
I usually start with a grind size of 3 using a Vario grinder.

Method:
Use scales.
1.Start the brew.
2. stop the machine when you reach 36g,
    and record how long that took.
3. The AIM is to get 36g out in about 25 secs. ... have a taste .... 
4. adjust the grind size 
5. repeat.

 AIM for 25 to 30 seconds..... that's roughly The Sweet Spot for most people


If at 25 seconds you get over 36 grams you should make it finer.
If at 25 seconds you get under 36 grams you should make it coarser.

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How to adjust shot volume on the Bambino
Adjusting the shot volume for the ‘1-Cup’ button:
1) Begin by grinding your coffee beans, tamping, and trimming the dose. 
2) Next, press and hold both the '1-Cup' and the '2-Cup' buttons simultaneously. After a couple of seconds, both buttons will flash.
3) Use scales to measure the coffee.
     Place the scale on the drip tray with a glass & set to zero.
4) Press the ‘1-Cup’ button to start your extraction
     & start the timer at the same time.
5) Once you’ve reached your desired weight, 
    press the ‘1-Cup’ button again to stop extraction & stop the timer.

Your desired shot volume is now saved to the ‘1-Cup’  button. 
These steps can be repeated for the ‘2-Cup’ button as well. 


Now that you have dialed this coffee using the bambino, try the same grind settings on another coffee machine. See if you can duplicate the taste.
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Dose
How much coffee do you start with?

Some things to keep in mind:
The more coffee you start with, the more work you need to do.
A better coffee grinder will make it easier to extract the coffee.
Better quality espresso machines will also make extraction easier.

The basket determines the correct dose that you should be using.
Remember that old school Italian baskets are probably only designed for 14-15g,
not the modern 20 to 22 g we are used to today.

The coffee itself will determine the dose.
Generally, the darker the roast, the less work you need to do to extract the coffee.
Thus, use a higher dose with a darker coffee.
Lighter roasts are more work to extract, thus use a smaller dose.
Time the shots.
Once you are in the ball park, tweak the dose. 
Remember: The more coffee, the slower the flow.


Ratio
How much espresso do we get at the end?
A shorter shot, or lower ratio, is going to have a more concentrated taste, meaning the mouthfeel will be thick and heavy. On the other hand, a longer shot or ratio will lead to a more 'watery mouthfeel' as the shot will include more water.

1:1 (ristretto)
1:2 (Normale - standard Italian espresso)
1: 3 (Lungo)


Grind size.
When you first dial in always start coarser than you need.
Then go finer, and finer.
Don't start too fine or you may get false results.


Brew Temp


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