If you ever watch a skilled barista, they will spend a lot of time regularly adjusting their grinder to achieve perfect extraction.
Why is this so....
The best baristas constantly adjust their grinders.
First thing in the morning, the beans and equipment may be cool/cold, so the barista must adjust the grinder to ensure the dose and tamp perform a correct espresso extraction.
As the day heats up, the beans will behave differently in the grinder and the barista needs to make minor compensations to the grind setting.
Opening a new bag of beans, even when they are from the same roast date, batch and origin or blend name can also result in grinder adjustment as the beans will have been suspended inside the bag at a different pressure and oxygen level compared to sitting in the grinder hopper.
You see, the process of grinder adjustment is never ending. People who never touch the grinder adjustment are missing out on wonderful coffee.
As coffee ages, it will require finer grind adjustment.
For our customers who may purchase different packs of coffee, you will absolutely need to adjust your grinder to suit the best extraction for espresso.
Other brew methods are more forgiving, e.g. plunger, perc, filter drip and to some extent stovetop are less sensitive to grind setting but just like espresso you will need to ensure you dose accurately.
As an example, Indonesians such as Sumatran, Java, etc. and soft South American coffees such as Brazils, Peru, Colombians, etc. can respond better with finer grind settings.
Harder beans from high-grown Central America and Ethiopians may require you to open the grind up a little coarser to achieve the perfect espresso extraction.
We strongly recommend you continously monitor the performance of your grinder via the grind setting so that you can enjoy coffee at it's best.