Soldato
@Participant I wouldn't even bother with the double walled as the single wall once you nail how to use them will produce a better drink everytime. I presume the spray is from the back pressure of the double wall and and pressure must have just gotten too high before the puck had been fully moistened.
As for you double basket pouring too fast I'd suggest setting the grind a little finer and tamp a little harder than a single shot. I only make singles when changing beans to check I have my grind settings and tamp pressure about right for that bean. I'd say i tend to tamp a little lighter on the single Where on the pressure gauge is your single shot hitting and then where is your double shot hitting?
What grind setting are you currently on?
As for you double basket pouring too fast I'd suggest setting the grind a little finer and tamp a little harder than a single shot. I only make singles when changing beans to check I have my grind settings and tamp pressure about right for that bean. I'd say i tend to tamp a little lighter on the single Where on the pressure gauge is your single shot hitting and then where is your double shot hitting?
What grind setting are you currently on?