Though typically our taste tests suggested a preinfusion of 2.5-3 bars is best, you could set this to anything from as low as 0.5 bars to even 7-8 bars or higher if you so desired.

You can also set each group to any pre-infusion pressure you want, independently from the others. So you can have three groups with three distinct pre-infusion pressure sets (assuming you are using a Slayer 3).

AND this works with all three groups brewing at the same time, or with staggered brewing, or whatever.

Slayer and other machines are NOT the same. Our approach is different with Slayer than it was, say with Treuh (synesso). This is partly because we grew in our coffee awareness–and what we wanted to highlight in coffee, those notes, especially evident in Ethiopian coffees. Slayer was not designed JUST to achieve brew temperature stability.

Seriously, I wrote something about “reverse engineering from the coffee, into a machine”. That’s because it REALLY did go like this. It was great fun. But the point is this combination of the mechanical valve and this pressure control resulted in coffee that was out of this world–just like we loved it.

Thanks for the questions. Look forward to the SCAA.

I’m just trying to get a feel for what this machine does and does not do. Can you set a preinfusion pressure higher than your mains water pressure? For example, if you get 2 bar from the water mains, can you set your machine to preinfuse at 4 bar? Presumably not, right? And presumably you can’t have a low preinfusion pressure and an end pressure higher than that? Can you change the rate at which the pressure tails off? For example, after going to the middle position, can you have your choice of taking 6 or 11 seconds to reach the inlet water pressure? Can you still fit a restrictor/gicleur to your machine to slow the pressure ramp up if you turn the paddle to the fully on position?

Sorry for all the questions; feel free to defer answers until SCAA … at which time I imagine y’all will be quite busy!

Cheers, and best of luck,

Luca

using a VFD and perhaps a custom made driver/programmer would allow the user to use whatever profile he/she wants. The config you guys have is somewhat limited, although still leaving behind most of the coffee machine world.

Would love to come by and chat with you in Atlanta, unfortunately I’m on the other side of the ocean.

Regards,
dsc.

We avoided using a multi-pump system (variable frequency drive). Essentially an inverter/rectifier for control, right? I like simplicity, and everyone here is a veteran of the war that complex espresso machines have been waging on the industry for years, so the tendency is to chose the simplest solution that won’t fail. That way we can keep our heads in the coffee clouds for longer and only have to infrequently swoop to earth to address something of a “technical nature”. And hopefully then, it’s just cleaning screens and stuff.

Will someone please ask me what happened when I brewed Duane’s Panama Esmeralda on Slayer? Or better yet, send me some great coffee!

Thanks again for your follow-up.

what do you have to do to get the slope drop at the end? move the lever back into the mid position?

Simply out of curiosity, why didn’t you use the inverter-driven-motor idea to control pressure?

Regards,
dsc.

what does A1 and A2 mean on the diagram?

Sounds like the whole idea is a merge of a spring fitted preinfusion chamber (slow pressure build up) and a standard delay preinfusion (flat bit on the diagram). Correct me if I’m wrong.

Regards,
dsc.

Shoot me an email…
-bry