Grind Reference Guide

This is a handy guide when trying to dial in your espresso. While this works for my coffee, my grinder and my machine, you can use this to help to "target" a setting relative to a previous coffee. If you grind your Kenya Thuti AA around 4 on your grinder (2.6 for me) but just received the Nicaragua El Avion (2 for me). You know you need finer by looking at my settings, so you can start your dial-in setting around 3.4 for example depending on your touch-point (zero point).
PDF Copy of this guide

• Grind size is specific to grinder, burr set and preparation & equipment. Generally, darker roast = coarser grind
• Grinder numbers also need to reference with touch-point or zero, where the burrs touch or cannot rotate
• Coffee by different roasters and age may extract differently

EXTRACTION METHOD:

• 12-25s pre-infusion @ ~2.5 bars 
• ~30s extraction time (primary focus on extraction yield not time)
• 17g in, 26g out up to 30g out subject to coffee profile
• Pressure & extraction profile: (pressure margin ±0.2 bars) graph below: