Tamp pressure question

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kav

Tamp pressure question

Post by kav »

I've been playing with my Vivaldi for a few weeks now and have been very very happy..
One thing I'm noticing is that 30lbs seems to be the approx recommended tamp pressure that most threads refer to.
On my machine, I'm barely tamping.. More like 10 lbs it seems.. If I tamp a little harder the machine will either choke or the extraction will take over a minute.. Am I doing something wrong?

I'm using a Vario with the vivaldi.. I've tried making the grind more coarse but this does not seem to help signficantly.
Endo

Re: Tamp pressure question

Post by Endo »

What does "more coarse" mean to you? You may need to move down 6 or so micro notches on the Vario to make a noticeable difference. Have you tried moving the macro down one notch?

I think there may be some debate on whether a light tamp is good or bad. I think if you can use a light tamp and fine grind, this is probably best since it means more coffee surface area and more flavour. But this is ONLY good if you can be sure of no channeling. This is why the botomless PF is so important.

Personally, I've had trouble getting a uniform and centered pour when using a light tamp. (I think it might have something to do with the tall puck on the Vivaldi where most of the compression happens only in the top layers). To get a more dense puck, I usually tap the PF a few times on the PF holder while grinding (something you can't do on the Vario unfortunately, which is why I prefer my Mazzer) and then I use a more powerful nutation style tamp, followed by a light 15lb polish or twist. To do this without choking the shot, I need to grind more coarse.

I'm not saying this is the best method. In fact, it might be making a worse tasting shot. So I often do the reverse (as you describe, fine grind and light tamp) just to be sure of which techique produces the best shot.

Of course all this depends on the coffee, freshness and even humidity. So all I can really say is; experiment. The right method is the one that gives you the best taste.
bgour
Macchiato
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Location: Vancouver, British Columbia

Re: Tamp pressure question

Post by bgour »

Note also that the common 30lb tamp for a 58mm basket equals 25lb in the Vivaldi's 53mm basket (approx 80% of the area, therefore 80% the force).
Vivaldi S1 V1, timer
Mazzer Mini
kav

Re: Tamp pressure question

Post by kav »

I've tried the max macro setting (right lever pushed all the way to the top) and various fine settings - but this was chocking the machine.
I finally moved the macro setting down about 4-5 notches, and moved the fine setting down about 9 notches. This is the current setting I've been using. If I use anything more than a very light tamp the 2 ounces will take 50+ seconds. If I just tap and tamp lightly, I can get 2 ouces at between 20-30 seconds. Even the slighest heavier tamp results in 35 seconds..

Could my vario require adjusting? Are you guys really able to use 30lb tamps?
Endo

Re: Tamp pressure question

Post by Endo »

kav wrote:I finally moved the macro setting down about 4-5 notches, and moved the fine setting down about 9 notches....
Could my vario require adjusting?
Where is the zero point on your grinder? If you calibrated it correctly (zeroed at macro 0 and micro 7 ), then you should be able to simply move the macro down 1 notch for good 30 sec espresso shots. If you are getting good shots at macro notch 3 or 4, and the grinder is not rubbing burrs at macro notch 0, then you have a problem since this is WAY more range than is normal.

There are probably a few grounds of coffee stuck under the lower burr carrier (a known problem on some grinders). You can either read about the fix for this on CoffeeGeek, or you can call Baratza and they'll provide you instructions to fix it.
oton

Re: Tamp pressure question

Post by oton »

Endo wrote:zeroed at macro 0 and micro 7
uh? Why is that?
Endo

Re: Tamp pressure question

Post by Endo »

Here's an example of a typical Vario setting for espresso:

Micro (left) at position 7 from the top. Macro (right) at position 1 from the top.
Typical Vario Setting
Typical Vario Setting
micro7.jpg (14.49 KiB) Viewed 26018 times
kav

Re: Tamp pressure question

Post by kav »

i never calibrated it out of the box. I just plugged it in and started using after running a few rounds of beans through it..
I'll check the manual on calibrating it. For sure I'm not running nearly your settings. My macro and micro are way down compared to that picture.
kav

Re: Tamp pressure question

Post by kav »

I've tried recalibrating the vario with no luck. There is little to no change between the top and bottom macro setting.
I'm going to give them a call in the morning to see what the suggest. This would explain why I can't tamp more than a few pounds without getting 60 second shots..
Endo

Re: Tamp pressure question

Post by Endo »

That's unfortunate. But, at least now you know it's simply a defective grinder. This can be fixed.

Once everything is back working, I expect you'll be very happy with the improvement in taste and consistancy.
oton

Re: Tamp pressure question

Post by oton »

kav wrote: Are you guys really able to use 30lb tamps?
Here you can watch my Vario settings; and 30lb double tamping. :smile:

http://www.youtube.com/watch?v=tZ657eXWK3w
kav

Re: Tamp pressure question

Post by kav »

Great video!!

Chris's refered me directly to Baratza. I called and spoke with Eric at Baratza. He was very helpful. He thinks the belt may be too tight. He has shipped out a replacement grinder! I'm hoping for better luck - great service though!

At least this explains the tamp problem.
Endo

Re: Tamp pressure question

Post by Endo »

Hey Oton, where did you get that fat PF handle?
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slo
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Posts: 419
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Location: Montreal, Canada

Re: Tamp pressure question

Post by slo »

I was curious as well?

My guess is Espresso parts UK. But this based on an illustration that could be wrong. I almost ordered one to check.

Is it comfortable? Is it spongy rubber?

Once again nice set-up!
Vivaldi II, Multiple (a collection really) Lever machines
Currently on deck grinders: Mythos and MXKR
Backup grinders: Robur, Major.
Toper Cafemino Electric and Poppery 1 roaster

I have a serious problem ... Can you guess what?
oton

Re: Tamp pressure question

Post by oton »

The PF is from http://www.happydonkey.co.uk/spaziale-b ... p2904.html

Unfortunatly they do not sell outside of UK already.
Is it comfortable? Is it spongy rubber?
Yeah, not bad. It feels cheaper than La Spaz PF (it weights less) but at the same time I like the lightness. Not rubber, matte hard plastic.
kav

Re: Tamp pressure question

Post by kav »

New Vario arrived today from Baratza! That is great fast cutomer service - thanks Eric!!

What a difference. The coarse grind is really coarse and the fine is really fine. Now the 30lbs tamp is coming into play. The learning curve starts all over again!

Thanks for all the help!
gene

Re: Tamp pressure question

Post by gene »

I'm on a tamp pressure venture at the moment also. Have a stock Vario out of box and never recalibrated.
Pour had regressed that I was getting three ounces in 35 seconds with approx 30# tamp.

Smartest thing I did was ask a question on this forum. Wow, what great feedback. Took advice and now occasionally time shot to insure getting 1.5 to 1.8 oz in 35 seconds.
If over then adjust L levers on VARIO up to get a finer grind...... til it results in 1.5 oz. tamped at 10-15#, in 35 seconds 15# because I was told S1 likes lighter tamp compared to 58mm portafilter machines.
The only thing Santa brought me was a $4.00 Oxo 2 OZ measuring cup from Bed, Bath and Beyond. That way can get much more accurate read-out.

My wife knows I am a calibration freak. Turns out the advice was to have right lever all way up and left lever 5-6 notches up.
Grind had changed over time and I didn't realize it it was so gradual....my shots were so thin and didn't taste nearly as well.
Turns out, after recalibrating the now worn in Vario present settings are all way up on R and 8th up on L.
One notch makes a world of difference.
Thanks guys!
gene
Endo

Re: Tamp pressure question

Post by Endo »

gene wrote:...... I was told S1 likes lighter tamp compared to 58mm portafilter machines.
Is that true? Personally, I've never had much luck with the light tamp. Actualy, I both thump the PF to settle the grinds and use nutation, both techniques which greatly compact the grounds.
gene

Re: Tamp pressure question

Post by gene »

True. Just a tiny bit of nutation with the new Cafelat tamper which has slight convex shape and lots of practice yields really good shots. Certainly danger of channeling is almost non-existent.
Of course using weigh scale to practice on is also key. Getting 15# tamp consistently is really difficult and takes lots of practice.
oton

Re: Tamp pressure question

Post by oton »

I'm wondering if there's a problem with my machine. Sometimes, with some beans, I can't grind fine enough to get a 20 second shot... with 16 grams. With 14 g is like making a tea. Had this problem with the compak k3, with the K30 and with the Vario. :?: I adjusted the pressure to about 8.2 bar, but it didn't work. :-(
symbology

Re: Tamp pressure question

Post by symbology »

Wow, what does the pour look like? Does it just flow like a river from the start, or does the puck hole up for a while, but finally give way to channeling?

What does the top of the puck look like afterwards?

What does the water look like when it exits your screens? is it dispersed across it, or flowing out of one section?

Maybe you need to get a pressure testing portafilter and validate your group pressure during a 25 second pour.

When pulling a blind water shot, does it always reach full pressure and hold it while the pump is running?
symbology

Re: Tamp pressure question

Post by symbology »

You could also try to drop the pressure down to 7 bar to see if that makes any difference.
Endo

Re: Tamp pressure question

Post by Endo »

Stale coffee or bad grinder are the only possibilities.

The Ulka pump is limited to 15 bar. The flow rate and pressure relationship follow this curve:
Ulka Pump Graph
Ulka Pump Graph
269_ULKA5_21_2.jpg (64.93 KiB) Viewed 25638 times
Since the top end is limited, on some cheaper machines they don't even use an OPV. I can still choke these machines that make about 14 bar at the basket using any of my grinders, so I doubt pressure is the reason.

Since you tried it on several grinders, the coffee (or perhaps severe channelling or a ridiculously light tamp) are the only possible reasons.

Have you tried nutation? This helps me out a lot as the coffee ages beyond 2 weeks.
symbology

Re: Tamp pressure question

Post by symbology »

If it is as simple as stale beans, I would grind coarser and dose higher and target a 23-25 second extraction (to start).
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GDK
God Shot
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Location: Ottawa, Canada

Re: Tamp pressure question

Post by GDK »

I recall having to grind finer with stale beans to keep extraction time at the same level.
symbology

Re: Tamp pressure question

Post by symbology »

That could be the problem though. Targeting the same extraction time. If the grind is too fine, you will end up with a slow extraction at the beginning, but then channeling gets real bad ruining any chance at a good shot.

As your beans age, it is better to simply up the dose and not change the grind. Obviously, you can only up the dose so much. It is possible that Oton may have gone too fine with his grind and his puck has no chance of holding up against the flow of water.
oton

Re: Tamp pressure question

Post by oton »

Wow, what does the pour look like? Does it just flow like a river from the start, or does the puck hole up for a while, but finally give way to channeling?
The pour flows fast from the start, so I know the shot will be too fast.
symbology wrote:What does the top of the puck look like afterwards?
Nothing special. Sometimes some typical LaSpaziale puck holes.
symbology wrote:What does the water look like when it exits your screens? is it dispersed across it, or flowing out of one section?
I think is dispersed, :?: but I'd like to be more like a shower...
symbology wrote:When pulling a blind water shot, does it always reach full pressure and hold it while the pump is running?
Yep, no problem. However when the shot is going too fast the pressure is lower due to not enough resistance.


I have set Vario to zero point and the K30 too, and with some coffees, I can't past from 20s/50ml ... Not staleness, 4 days old, 7 days old beans, I have some 1 month old beans with the same problem. :|
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GDK
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Location: Ottawa, Canada

Re: Tamp pressure question

Post by GDK »

Outch, I was going to upgrade soon to a Vario from a Rocky because I have similar problem with some coffees - I grind 1 notch above the zero point on the Rocky for most beans and can hardly reach 25 seconds. I was hoping the Vario would help but that is not certain now.

In your situation, the only culprit might be dosing. If you dose too high, the screen bolt may be pressing against the puck thus causing a crack which might lead to a fast pour.
Last edited by GDK on Fri May 13, 2011 7:13 pm, edited 1 time in total.
oton

Re: Tamp pressure question

Post by oton »

Well, do not discard Vario yet. I have seen more reported problems about not enough fine grind for the rocky, it seems a usual problem; however I've not read this problem with the Vario, K30 or K3... It must be *me* :(
Louis

Re: Tamp pressure question

Post by Louis »

oton wrote:Well, do not discard Vario yet. I have seen more reported problems about not enough fine grind for the rocky, it seems a usual problem; however I've not read this problem with the Vario, K30 or K3... It must be *me* :(
I bought coffee from a new shop in Montréal: Café St-Henri (they own the first Strada in the city). The roaster has a very good reputation, also working at Café in Gamba. Even with the Vario motor working hard, empty, at a very fine grind adjustment, I could only get gushers with the Silvia. I now need to take a jar from the freezer and see what I can do with the Vivaldi.

Seems like you are not alone...
symbology

Re: Tamp pressure question

Post by symbology »

How many baskets do you have? Try another basket if you can. Even the single basket with a 7-8gram dose.

Do these beans ever choke the machine?

How fine do the grinds feel?
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slo
Barista
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Location: Montreal, Canada

Re: Tamp pressure question

Post by slo »

I can report having similar problem with some Ethiopian beans. These are often roasted very light to keep the varietal characteristics.

I roast myself, so freshness is not an issue. This occurs with any of my 6 baskets and with any of my 3 grinders at any setting I could try.

I really think that it is only caused by the beans somehow. Something to do with the roast level (I never roast an Ethiopian coffee past Full city), oil content, bean hardness (less fines produced in the grinder), ..., or something that I cannot understand.

To remedy this situation, I elected to updose the shots significantly. This somehow allow the coffee to settle and restricts the flow enough to get a proper extraction. Of course this will produce very intense coffee.

Of course this may not be the same for you but you could try.
Vivaldi II, Multiple (a collection really) Lever machines
Currently on deck grinders: Mythos and MXKR
Backup grinders: Robur, Major.
Toper Cafemino Electric and Poppery 1 roaster

I have a serious problem ... Can you guess what?
Louis

Re: Tamp pressure question

Post by Louis »

slo wrote:These are often roasted very light to keep the varietal characteristics.
The issue I had was only with this blend/roast and it is the lightest roast I ever tried and the smallest beans I've seen (in my short 2 years experience with the Silvia).

Now I really need to try it again this week end...
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