Barista Technique: Diagnosis of Extraction Problems
Last Article We talked about making your perfect espresso.
You have done everything right and sometimes your espresso just don't taste just like you wanted.
Think about what seems off and try some of these tips and tricks we will give you.
Espresso is mostly depen on shot time and volume, since these are easiest to measure.
The volume for espresso are total volume, for crema and liquid.
And the time, means it turning on the pump and see the first drops of espresso emerge from the basket varies from machine to machine.
So espresso extraction times are specified from the moment the pump is turned on.
This Article We will specify the diagnostics for shot ending color and volume, since these have the most intuitive correspondence to espresso taste.
You should end the shot at the specified color, and then set the grinder to get the specified volume.
Your espresso brewing time is way too short ?
Thin and sourish: The mark of underextraction.
Grind finer and stop lighter, so the volume stays the same. If the taste is extremely sour, also raise the temperature.
We call this "under-extracted" espresso shot.
The water is just flying trough your coffee cake and espresso tastes very light acid. How to fix this?
There are three ways to fix this kind of problem: Dose less coffee, grind your coffee coarser and tamp it much harder.
Your espresso brewing is taking way too long ?
Instant coffee taste: The mark of overextraction. Grind coarser and stop darker, so volume stays the same.
If the bitter taste is prickly-sharp rather than dull, also lower the temperature.
We call this "over-extraction" espresso shot.
The water just can't get trough your coffee cake that easilly and your espresso tastes very bitter.
How to fix this ?
Dose more coffee, grind the coffee finer and tamp lighter.
Diagnosing the Taste and Extraction
Diagnostics means tasting the espresso and correcting its deficiencies by adjusting setup or extraction parameters.
Correcting for one deficiency would never interfere with correcting for another. there sometimes are conflicts, and you must prioritize.
Firstly, go to gross crema deficiencies, since these indicate that some parameter of the shot is well outside proper espresso range.
Secondly, is taste flaws that make a shot undrinkable.
Finally, with these eliminated, you can work on fine-tuning everything to get the most harmonious taste.
Your espresso shot tastes sour ?
This can be caused by three key factors:
Coffee that is a little too fresh. Try aging your coffee for a couple of extra days (never longer than three weeks though) to de-gas your coffee.
You’re under extracting your coffee. Try grinding finer to slow down shot times.
The brew water is a little cool. Make sure the temperature of your machine is above 94 degrees Celsius.
Overly sour: Raise the temperature. Short term, trying stopping lighter and grinding finer to keep the volume the same. If it's really bad, start-dump.
This can be caused by coffee that is little too fresh.
In this case our brewing time is short and we stopped the chemical reaction between water and coffee.
Check your roasting date, brewing time and your water temperature.
Your espresso shot tastes bitter ?
Overly bitter coffee can also be caused by three main factors:
- Dirty equipment! Check that your portafilters and group heads aren’t dirty. Clean everything and wipe down the insides so they’re clean of any coffee residue. We recommend doing this every 30-60 minutes during service.
- You’re over-extracting your coffee. Try grinding coarser to speed up shot times.
- The brew temperature is too hot. Make sure the temperature of your machine is below 96 degrees Celsius.
Overly bitter: Lower the temperature. Short term, try stopping darker and coarsening the grind to keep the volume the same.
This can be cause by coffee which was roasted more than 3 weeks ago.
In this case, water got way too much out of our coffee cake. This type is also "over-extracted".
How to fix this?
Also check for roasting date and decrease your brewing time and your water temperature.
Sometimes your coffee is thin and weak with a fast-dissipating crema.
Firstly check the roast date of your coffee.
When coffee is roasted and produces carbon dioxide as a byproduct of the roasting process.
When your coffee is very fresh will see a lot of bubbles in the crema and a faster crema breakdown.
Allow the beans a couple of days to rest and de-gas to obtain a more stable crema.
However, keep in mind that coffee will become flatter and staler from 15 days past the roast date onwards. In addition, the longer you allow your coffee to de-gas, the more the flavour will change as well.
As a starting point for better quality and a more stable crema, try brewing with coffee that’s between day seven and day 21 past roasting.
Your espresso shot has almost no crema ?
If you don't see any crema in your cup, two solutions are possible.
First, your coffee is too old or the puck was not resisting the water enough.
To get more crema in your cup use fresh roasted beans, grind your coffee finer and dose more coffee.
Your whole espresso is crema ?
This can happen if your beans are still fresh roasted and they are still holding the gas from the roasting process.
If your espressos have big amount of crema, all you need is to give your coffee a little bit more time.
As you can see, most of these problems can be easily avoided by following a brew recipe, using fresh coffee and employing the appropriate technique when preparing your espresso.
If you’re still struggling, come and visit us at one of our blog to know more about Espresso issue.