Volume Dosing

[Jack Rabbit Slim]

Newbie here......I'm wondering why I only get 3/4 oz. to 1-1/2 oz. shots when I am pulling a double shot? I reasoned that since the Mini Vivaldi is programed to to dispense a certain amount of water .....the volume of the finished shot should be the same every time......I assumed that only the "time" it takes to pour would vary.

[JohnB]

If you are letting the machine cut the shot the volume will vary by your grind & how hard you tamp if you cut the shot at a set time(25 sec). Many of us program one button to 2-3 ounces & only use that one for warming flushes. The other button gets set to 3-4 ounces so we can cut the shot manually at the first signs of blonding. Sometimes I grind/tamp for a 25 second shot & sometimes I'm going for a long, slow shot that may run 40 seconds. Either way I don't want the machine deciding when to cut the shot. Are you using warming flushes to bring the grouphead up to temp after an idle period.

[chas]

Yes, what John said. The machine WILL consistently deliver the programmed amount of water to the top of the puck every time. Only the amount that comes out the bottom varies due to the variable amount that remains in the grounds.

[Jack Rabbit Slim]

I didn't realize my grind/tamp was still that inconsistant from shot to shot. I guess the learning curve is a bit steeper than I anticipated. I am using an espro tamper that clicks..... I do like your idea of programing a 3-4 ounce shot and stopping the pour manually. I had hoped the programed volume dose would work well for my three daughters (ages 8 thru 12)......they are real excited about using the machine and have already started making their own drinks. It was one of the reasons I chose the Vivaldi over the Duetto.

Is that piston driven Macap tamper worth the money?.....I could see my girls learning to use that real quick.

[JohnB]

I hope you opted for the "no burn" steam wand if the kids are going to play with the Mini. I'd worry less about the tamp, increase the volumetric dosing & teach the girls what blonding looks like. Either that or use one button for the kids/flushes & the other for you. How do you keep the kids glued to the floor after they have coffee?

[Jack Rabbit Slim]

Ha!

Six penny nails through their feet into the floor work well on weekends.......when they leave for school....I pry up the nails and fill their backpacks with rocks!

[Endo]

While I usually cut the shots manually (when blonding), I notice I'm getting guite a bit of variation when using the pre-set volume dosing buttons.

I set the single dose to 30ml (1 oz) but I sometimes get 30ml and other times 40ml depending on the grind. I thought the flowmeter would keep the volume the same regardless of the grind and only the time would change (hence the name "volumetric dosing")? But instead, the volume seems to go up as resistance is reduced (more coarse grind). If the PF is empty, I get about a 50% increase in volume. Is this normal?

[chas]

The difference is in the amount getting absorbed by the coffee.

[Endo]

Ahhhh....of course.

I forgot about that. Now it seems obvious.