Dosing and grind depends on the machine and basket as well as the beans and what result you enjoy best.
Light roasts often don't follow the typical rules and become sour or bitter from under or overextraction. Some work best with approximately 45 sec extractions and larger doses in larger baskets, ime... Almost everything I buy is a lighter roast and for my machine, I use an average of 24g in a triple basket with 40 sec extractions and go for ~48g out. It's a big shot but it also allows my machine to go through the entire pressure profile of 9 to 5 bar. With the right dose and grind I often get a very constant output flow, while it's more typical for volume to increase as the shot is pulled with a pump machine that doesn't use a declining pressure profile.
This is also why, while I think the idea of a pressure profiling machine or the Decent Espresso DE1 is a great idea, they are often setup very close to what a spring-lever machine does anyways, and ime it's possible to achieve a very even flow from start to finish with a spring-lever.
Light roasts often don't follow the typical rules and become sour or bitter from under or overextraction. Some work best with approximately 45 sec extractions and larger doses in larger baskets, ime... Almost everything I buy is a lighter roast and for my machine, I use an average of 24g in a triple basket with 40 sec extractions and go for ~48g out. It's a big shot but it also allows my machine to go through the entire pressure profile of 9 to 5 bar. With the right dose and grind I often get a very constant output flow, while it's more typical for volume to increase as the shot is pulled with a pump machine that doesn't use a declining pressure profile.
This is also why, while I think the idea of a pressure profiling machine or the Decent Espresso DE1 is a great idea, they are often setup very close to what a spring-lever machine does anyways, and ime it's possible to achieve a very even flow from start to finish with a spring-lever.