Adjusting and dialling in a coffee grinder is a crucial skill for achieving consistent and high-quality coffee extraction. It involves finding the right grind size and other parameters to achieve the desired flavour profile and extraction characteristics. Here are the fundamentals of coffee grinder adjustment and dialling in:
1. Start with a Baseline:
Begin with a reference point, which could be the current grind setting you're using.
2. Understand the Impact of Grind Size:
Grind size affects the rate of extraction. Finer grinds increase extraction time, while coarser grinds slow it down. Smaller particles allow water to interact more with the coffee, leading to stronger flavours.
3. Adjust One Variable at a Time:
To isolate the impact of each adjustment, change only one variable at a time. As we know the target brew time, our variables are the grind size and the dose.
4. Adjust the Grind Size:
Begin by changing the grind size. If your coffee is extracting too fast (under-extraction), make the grind finer. If it's extracting too slowly (over-extraction), make the grind coarser.
NB: When adjusting the grind size it is important to manually dose and weigh the coffee you have in the portafilter, to ensure that variable remains the same.
5. Evaluate Extraction:
Brew a coffee using the adjusted grind size. Taste the coffee and assess its flavour, acidity, body, and overall balance. Note any changes compared to your reference point.
6. Observe Flow Rate:
For espresso, watch the flow rate. If the coffee flows too quickly, it might be under-extracted. If it drips very slowly or chokes the machine, it's likely over-extracted. Our machines even tell us the flow rate in ml/s.
7. Fine-Tune:
Continue making small adjustments to grind size (while maintaining the 18.5g dose) until you achieve the desired extraction time, flavour profile, and visual cues like crema thickness / colour.
8. Modify Dose:
Adjusting the grind size will often have an effect on the dose, as grinding finer or coarser will mean less or more coffee will be ground in that time respectively. Once you have found the correct grind size, it is now time to set the dose on the grinder to give us 18.5g.
9. Consider Other Variables:
While grind size and dose are primary factors, other variables like water temperature, water pressure, coffee freshness, atmospheric temperature & many others can also impact extraction.
10. Consistency is Key:
Once you've dialled in your grinder for a specific coffee and brewing method, aim to maintain consistency in your process. Consistency leads to reliable and repeatable results. Always keep one eye on the shot timer and regularly check the grinder is still dosing 18.5 or 21.5g accordingly.
Dialling in a coffee grinder is a dynamic process that requires a balance of patience, experimentation, and understanding of how each adjustment affects extraction. With practice, you'll become adept at maintaining the high standards of espresso production that we hold sacred!
