Sour or bitter shots on ECM Puristika vs Lelit Mara X (Eureka Single Dose Pro)
I recently picked up a used ECM Puristika for a bargain price (€500). It’s in good condition. I cleaned it thoroughly, backflushed the grouphead and everything seems to work properly. For comparison, I also have a Lelit Mara X that I bought new about a year ago. I’m using the same grinder, the same coffee (medium roast, local roaster, around 8 days off roast), and I’m trying to keep the recipe the same. But I consistently get a much better tasting espresso from the Mara X. With the Puristika, the shots often turn out either too sour or too bitter. I can’t seem to find that sweet spot the way I can with the Mara X.
I’m using a Eureka Mignon Single Dose Pro.
The previous owner told me they always used filtered water, and the water coming from the group head tastes completely normal to me.
I’m wondering what could explain the difference. Could it be a difference in brew temperature? Or could it be related to pre-infusion?