Boren The preinfusion of the E61 was to soften the “blow” of the very fast rotary pump ramp up. This allowed the puck to saturate a little before it was hit with full pressure, the idea being to limit the chance of fracturing due to compression when dry.
In reality the rotary pump ramp up is very fast, so it’s of limited use, although it must have some effect, but only for 1 second or so.
The vibration pump actually has a far more forgiving ramp, nice and gradual, so doesn’t really need the preinfusion temperature. It’s also one of the reasons the Lelit Bianca has the low flow feature. I’m actually going to do some videos on the V3 Bianca soon, as I feel the reviewers are not really doing it justice, or providing anything helpful re usage to the community. I just need the time to get round to it over the holidays.
As for the solenoid group, my personal opinion is that it’s superior for a number of reasons:
- Simpler mechanicals, less wear, much longer service life before replacing parts
- easier maintenance (e.g. backlushing as often as you want, no lubing needed, nucleus replacement etc)
- Much better for pressure profiling, without having to much the group about
- Allows for certain automation and safety a lever E61 cannot do. e.g. with a lever E61 that brew boiler can happily boil dry, with the solenoid one…not so much.
- Heat up a little faster
The manufacturers are reluctant to use them when they should, because they are afraid of what retailers, influencers say and end user experience. Even ACS don’t want to put a solenoid group in the Vesuvius, even though it would be a superior solution for the machine.
Unfortunately sometimes people get what they ask for, not what they need. I would prefer a solenoid E61 every day of the week…even in Bianca. etc..
As Jake said, Minima has a superb ramp rate!