How to dial in espresso when using a single shot filter basket. Compared to double shots, there’s almost no information online about how to use them properly! So I’ll give you the recipe, and then go a bit more in depth as to why you should be aiming for these numbers as a starting point:
Yield: 20-22gr (or the brew ratio of your choice)
Time: 15sec (for a standard 1:2 brew ratio)
Why these numbers?
In my experience with most single shot baskets, a 9gr dose is simple too low to fill the basket and achieve even flow, so I recommend using somewhere between 10-11gr.
Once you decide on a dose, in order to achieve the same extraction as a double shot basket, you want to follow the same brew ratio and extraction time per gram. (Aka, scale each value according to the change in dose). This ensures that you are achieving the same flow rate through the puck, and therefore the same extraction time per gram of coffee.