Brew pressure and start-up time basic questions

[spazheadnewb]

Hello All:

I recently purchased a gently used Mini Vivaldi but with an upgraded temperature control panel.

See picture below:



I have a few basic questions:

(1) The previous owner installed the brew pressure gauge on top. I get a reading at about 11 bars. If I don't tamp as hard will the reading go down? Is there a way I can adjust this down to 9 bars? I downloaded the manual from chris coffee but it only contains the mini vivaldi ii where there is a dual manometer. So I'm not sure where to adjust if necessary.

(2) How long do you usually wait for the machine to warm up? I have the temp set at 93C and it takes about 15 minutes or so to get to the stage when all of the lights are ready (not blinking). I'm brewing black-cat and was told that around 200F is ideal to bring out the chocolate notes of this blend. Should I be waiting a lot longer say 30 minutes?

[richardcoffee]

I warm up the brew boiler for an hour with good results. I think that's what most folks do. Then I turn on the steam boiler which only takes about 5 minutes to come up to pressure. Of course, if you're not making milk drinks, there's no need for the steam boiler to be on.

[spazheadnewb]

Thanks. Does anyone know where the valve adjustment for brew pressure is on the mini vivaldi 1? I am constantly getting 11 bars with the rubber backflush disk.

Also what is standard procedure for replacing the gasket on these machines?

With my old gaggia I would remove the screens and screen holder then turn the machine on it's back, insert two small screws into the gasket and remove with pliers.

[richardcoffee]

Sorry, I can't tell you about the brew pressure. But as for changing the gasket, you know the screens on this guy are held in place with a hex head screw/bolt. Did you get the hex wrench to remove it? All I do is unscrew the bolt and out come the screens and the dispersion block. Then, it's a pretty easy task to get the gasket out. I just use an old ice pick I have or a small screwdriver to pry it out. My problems have been getting the new one in. The gaskets I have are a pretty tight fit. But, I didn't seem to get much sympathy from the folks here so I have to assume it's my weak hands. Anyhow, the directions seem to be to just start on one side, wedge it in the best you can and then tighten the portafilter in to secure the new gasket.
As for the brew pressure, have you tried pulling a shot with coffee in the basket? My experience is that the brew pressure can vary quite a bit depending on the grind, the tamp and how dark the coffee is. You may, in fact, not have a problem.

[spazheadnewb]

Richardcoffee: Thanks again for the reply.

I just changed the gasket. What I did was remove the nut with a ratchet set. I didn't get the tool shipped with the unit.

I then hand screwed in a small screw into the gasket itself and removed it by pulling down on the screw. After this I carefully turned the unit on it's side to jam in the gasket. It is a tight fit and it was a pain to place it in with the unit upright.

As far as the brew pressure I checked with the backflush rubber disk and it still read about 11.5 bars of pressure.

Any opinion out there on whether I should adjust this down to 9 bar?

Here is a picture of the internals from the front

[Endo]

Yes. Adjust it down to 9.5 bar.

You can easily do this by holding the OPV body and turning the brass hex nut on the bottom (see photo). You'll likely need a wrench to turn it (though I'm just barely able to turn it with my fingers).

Can you show a picture of your top mounted brew gauge? I'm curious to see since I have the same Mini V1 and use a portfilter gauge to check brew pressure.

OPV adjustment nut

Untitled.jpg (76.3 KiB) Viewed 32718 times

[chas]

Also, this is covered step by step including photo in section 8.1 of the on-line manual available by clicking on the VII/VII Mini Site link at the top right of this web page.

[spazheadnewb]

Chas/Endo:
Thanks for the reply.

I did notice that it is covered in the manual but wanted to make sure the v1 and v2 were the same.

Endo: I will post a picture of the top of the unit showing the brew pressure gauge.

Also:

Can I program the single and double shot buttons without coffee in the portafilter? The person who had it before me programmed the double shot button for 20 seconds and the single shot button for 2 seconds.

Is there a way to over ride the programming? I guess this can be done by programming the single or double shot buttons for longer than needed and cutting it short?

[spazheadnewb]

I also wanted to add:

I called Chris Coffee service and they were very helpful. They told me that the v1 can be changed out to look like the v2 by changing out the front panel and installing a dual manometer just in case anyone wants the dual manometer on the front like the mini v2.

[Endo]

Can I program the single and double shot buttons without coffee in the portafilter? The person who had it before me programmed the double shot button for 20 seconds and the single shot button for 2 seconds.

Is there a way to over ride the programming? I guess this can be done by programming the single or double shot buttons for longer than needed and cutting it short?

Yes. It's very easy to change the shot volume. Read the manual (don't mean to sound rude, it's very useful).

I called Chris Coffee service and they were very helpful. They told me that the v1 can be changed out to look like the v2 by changing out the front panel and installing a dual manometer just in case anyone wants the dual manometer on the front like the mini v2.

It will run you about $150. A total waste of money IMO. Why pay $150 to watch a needle vibrate around 9 bar every time you do a shot? I much prefer the big single gauge with the easy to read steam pressure. I add a $10 gauge to my spare PF once a year when I check my brew pressure (hasn't changed yet). It's more accurate as well.

[Louis]

Can I program the single and double shot buttons without coffee in the portafilter? The person who had it before me programmed the double shot button for 20 seconds and the single shot button for 2 seconds.

My answer would be no. When coffee is in the portafilter, it will retain some of the water. Hence, the amount of water you will get in the cup with and without coffee will be different.

Note that it is volumetric, not time based, it measures a preset amount of water. Time has nothing to do with it.

Is there a way to over ride the programming? I guess this can be done by programming the single or double shot buttons for longer than needed and cutting it short?

No override. As you said, you would need to re-set the shot buttons to the new amount of water.

[MDL]

Wrong answer.

The original poster is correct, I believe that you can program a large volume and you can then always cut the shot short by pushing the button again.

[Abnuceals]

I believe that you can program a large volume and you can then always cut the shot short by pushing the button again.

It is actually the way I do it and I'm sure I'm not the only one to do that. I programmed the double shot for 2 oz but most of the time, I cut it when there is 1.5 oz in the cup. It's a lot easier than doing the contrary

[Louis]

Wrong answer.

The original poster is correct, I believe that you can program a large volume and you can then always cut the shot short by pushing the button again.

My bad. I read it backwards... What I meant is that you can override the programmed dose to lenghten it.

[Endo]

People's shot volume setting have been discussed at length. But I think most people set one button to about 50ml, and use that for warming and cleaning. The other button they set to about double the first , say 100ml, but always cut the shot manually.

Volumetric shot cutoff is never really used (except for cleaning and warming, and you are busy getting the milk or grinding). But it sounds nice on the brochure.

[chas]

I kind of went the opposite route. I set the second button to double the volume of my main shot button rather than half. I use that "quad shot" button when forward flushing to give me plenty of time to scrub the group head and gasket and then get the PF back on so that it can run some hot water through the PF to warm back up.

[Endo]

I kind of went the opposite route. I set the second button to double the volume of my main shot button rather than half. I use that "quad shot" button when forward flushing to give me plenty of time to scrub the group head and gasket and then get the PF back on so that it can run some hot water through the PF to warm back up.

When you have a reservoir, you learn to clean with less water.

[spazheadnewb]

Thanks everyone for your input.

Endo: here is a pic of the valve. I will take a better pic with the cover off for you.



Question: what size wrench should I be using for adjusting the pressure ?

I'm thinking 22 mm but want to make sure before I go out and get a metric wrench.

My adjustable wrench does not fit. That's a pretty tight space for any adjustment.

Also just to double check when I place the blind filtet in the portafilter basket the valve reads close to 12 and as discussed should be closer to 9.5/10.

Do I turn this nut counterclockwise to lower and how many turns roughly to get back down to proper brew pressure?

[spazheadnewb]

Off topic : I've been trying metropolis redline and have been able to get some decent tasting espresso with some nice chocolate notes.

Recently however I've been told to cut back on caffeine consumption. Any good recommendations for decent tasting decaf?

[Endo]

Thanks everyone for your input.

Endo: here is a pic of the valve. I will take a better pic with the cover off for you.

Nice! That's a good idea keeping the gauge hidden away under the cover. I never thought of that. After all, how often do you need it?

I'm curious to see where it's attached. I assume it's tee'd off the grouphead. (At the same place where the p/i chamber attaches).

Question: what size wrench should I be using for adjusting the pressure ?

I'm thinking 22 mm but want to make sure before I go out and get a metric wrench.

My adjustable wrench does not fit. That's a pretty tight space for any adjustment.

It's a 21 mm actually. But to be honest, I could never get mine to fit. Maybe from the back it would be easier to reach. What works best for me is fingers, or needle nose pliers with silicone tubing over the end.

Also just to double check when I place the blind filtet in the portafilter basket the valve reads close to 12 and as discussed should be closer to 9.5/10.

Do I turn this nut counterclockwise to lower and how many turns roughly to get back down to proper brew pressure?

With the blind basket in and wrench on the lower valve nut flats, move your wrench to the left (I think) to lower the pressue to 9.5 bar. Try turning it 1/4 a turn to start. Don't worry to much. Just try it and see what you get, then adjust again. You can't do any harm.

[bonganim]

That's a nice solution. I wish to know where the gauge is connected. Maybe with photos as well.

[fredegar]

indeed nice place for the gauge , but it would be cool to have detail picture of where it is attach and where you connect the gauge

i have a mini vivaldi v1 2013 , and plan to install brew gauge

[chas]

This is where it attaches on a plumbed in V2. However, I am not sure whether this spot exists on a Mini. Perhaps another mini owner can let you know.

s1plumb.png (361.87 KiB) Viewed 27339 times

If your mini does NOT have the mechanical pre-infusion device installed on the left side of the brew head then there will be a bolt blocking the threaded port where it normally connects. This would be an even better location to connect a pressure gauge since it is right at the brew head. The normal location is closer to the pump outlet and there is a pressure drop through the tubing that runs from the pump output to the brewhead.