Average Offset?

[Endo]

So what's your calibrated temperature offset?

I'm curious to see what the average and standard deviation of the offset is from a sample of about 20 machines.

Mine was at 0C (uncalibrated mk1 model). I did some testing and I switched my machine to mk2 mode and entered an offset of -1C.

I won't include my machine in the stats, since it was not accurately calibrated. I'll just use the ones done using a Scace and the Chris offset method.

[JohnB]

MIne was set to 0* but that was as high as they could go at the time. I now have it set to +2*.

[Endo]

MIne was set to 0* but that was as high as they could go at the time. I now have it set to +2*.

Oh...that's interesting. I thought the hardwired offset would have been smaller than necessary (machines biased towards being too hot in other words) so that you would always have to do a negative software offset (cooler). Is it possible they made the hardwired offset larger on the new boards since they now allow both + and - software offsets?

I wonder what LaSpaziale does on their Euro Mini-Vivaldi's (like mine), since they are shipped in mk1 mode which has no software offset. Nothing I assume. I may need the Scace after all. Not for taste necessarily (most my shots taste best at my 91C to 94C settings). Mostly for curiosity sake.

[chas]

I may need the Scace after all. Not for taste necessarily (most my shots taste best at my 91C to 94C settings). Mostly for curiosity sake.

Dont' forget the logging digital thermometer, too!

[sakurama]

I'm pretty sure that I ended at +2° also but I'll check it when the Scace comes back.

[michael]

my newer machine is now set at +2; adjusted by cc during a recent repair and confirmed by me with the scace

my older machine (also from cc) was set at -2 on receipt; checked with scace recently and reset to 0 and need the newer software since the temperature is still 2 degrees too low according to the scace

[chas]

The last time I used the Scace on mine I ended up at +2C.

[Endo]

Seems like many are set to +2C.

Still early but it seems +2C would be a better default setting to use for anyone with an uncalibrated machine (for non CC models set to zero). No?

[ebprod]

I've got the rented Scace from Sakurama, and have been using it for the last day or so.

My machine came from Chris Coffee with the offset set to -1. I always thought that the setting was too low, and it seemed to get worse after doing the pre-infusion upgrade. Just through my own experimentation I had put the offset to +2.

Now, with the Scace I have found that that was still way too low. I now have my offset at +4!!

I started my measurements with offset at 0, and the temp set to 94c. After a couple of shots, I was barely making it to 90c. I moved the offset up until the reading became accurate and settled at +4. I am taking the portafilter out of the machine for 40 seconds in between readings.

I also found that I needed to wait an additional 10-15 seconds after the light stopped blinking to get an accurate reading. If I take a reading as soon as the light stops, I would need to have my offset at +5.

Has anyone else found that Chris's settings were that far off? Unless the board upgrade changed something, this machine would be impossible without the + setting option.

-Joe

So what's your calibrated temperature offset?

I'm curious to see what the average and standard deviation of the offset is from a sample of about 20 machines.

Mine was at 0C (uncalibrated mk1 model). I did some testing and I switched my machine to mk2 mode and entered an offset of -1C.

I won't include my machine in the stats, since it was not accurately calibrated. I'll just use the ones done using a Scace and the Chris offset method.

[Endo]

Did you warm up everything for at least one hour?

Is the Scace calibrated?

Interesting what you say about the preinfusion. I'll have to think about that one.

[ebprod]

I don't turn my machine off- just the steam boiler at night. I left the Scace in the machine for several hours before using it.

I put the Scace in boiling water and it was perfect (209.9 for our elevation and barometric pressure)

-Joe

Did you warm up everything for at least one hour?

Is the Scace calibrated?

Interesting what you say about the preinfusion. I'll have to think about that one.

[JohnB]

Are you running 2 oz flushes through the scace? If so how many seconds does it take for the 2 ozs to pass through the Scace? One piece of advice that I got from Richard is to drop & clean your screens before testing with the Scace. A few grounds can partially clog the Scace drain hole & throw off all your readings.

[ebprod]

I'm running 2 oz through the Scace. It takes about 27 seconds with the pre-infusion at 3 seconds. I've tried all the variations of my normal routine and I almost always hit my target temperature on the third flush, no matter what temperature setting I am using. It will stay there for the next 4-5 flushes, but if I do them with only a 40 second pause it will creep up a degree by the time I hit 10 flushes. I rarely do more that 2-3 shots at a time, so I think I am good where I am at +4.

-Joe

Are you running 2 oz flushes through the scace? If so how many seconds does it take for the 2 ozs to pass through the Scace? One piece of advice that I got from Richard is to drop & clean your screens before testing with the Scace. A few grounds can partially clog the Scace drain hole & throw off all your readings.

[michael]

i had a similar experience with my offset setting; my machine was set by chris coffee at -2, but when i tested it with the scace i found i was off by 4 degrees (the black cat was always tasting a bit sour at their recommended temperature, but with my machine i was brewing it at 89); unfortunately, this machine has the old software so the best i could do was set the offset to 0 and overshoot the temp by 2 degrees

i ran a bunch (really a lot) of shots with the scace (over one week), but never timed the 2 oz through the device; if there were a few grains of coffee in the scace, would that make the reading from the scace higher or lower

[Endo]

It is really looking like they increased the hard-coded offset on the new machines to allow for the soft +/- offset capability.

I have increased my offset to +2C (based purely on statistics). Taste is much better when I use the recommended temperatures for the Ethiopians (91C). I used to use 93C or 94C to get the right taste, so I was pretty sure my machine was running cool.

My styro-cup method seems to run about -3C low. Needs some tuning I guess but it is just too dang messy (sprinkler!!!).

[sakurama]

Are you running 2 oz flushes through the scace? If so how many seconds does it take for the 2 ozs to pass through the Scace? One piece of advice that I got from Richard is to drop & clean your screens before testing with the Scace. A few grounds can partially clog the Scace drain hole & throw off all your readings.

I've been cleaning it out every time it comes back - there's hardly any grounds in it.

It seems to me that with 3 seconds preinfusion the Scace runs 30 seconds total for me - exactly the same as my shots.

[JohnB]

I revisited my testing this morning & am still playing with it but it looks like I may end up with a +3* offset instead of the +2* I was using recently. My machine originally came set to 0* but that was as high as it could go at the time.

I'm running 2 oz of water through the Scace in 25 seconds. For some tests I'm duplicating my dose in the basket with p/f locked in & for others I'm pulling the p/f for 30 seconds between flushes like CC does.

[Endo]

When are you Scace guys getting a data logger so we can see the shot stability?

[JohnB]

When are you Scace guys getting a data logger so we can see the shot stability?

I've got one, just have to load the software in my computer & figure it out.

[michael]

is it possible that the offset has to be reset from time to time; not sure why that would be necessary, but i noticed that john mentioned that he recently adusted the offset on his machine; when i had to send my machine back to cc for a repair, i asked them to confirm the temp offset and they said they had fine tuned it a bit (this was before i used the scace to check it myself)

[Endo]

is it possible that the offset has to be reset from time to time; not sure why that would be necessary, but i noticed that john mentioned that he recently adusted the offset on his machine; when i had to send my machine back to cc for a repair, i asked them to confirm the temp offset and they said they had fine tuned it a bit (this was before i used the scace to check it myself)

Good question. It would have to be the sensor. Would scale buildup on the sensor change the reading? If it does, I would think the scale would act as an insulator meaning you would need to reduce offset over time to keep the brew temp the same. Opposite to what you guys are reporting. But that's just a guess.

[JohnB]

Keep in mind that until last July CC could set the offset no higher then 0* so some of us are simply setting the offset where it should have been in the first place. Of course this does not explain why those with a negative offset from CC are having to reset much higher.

I'm going to recheck in the morning but right now I'm up to a +4* offset setting. One interesting thing all the testing has shown is that when the temp lights are going off or flashing during a shot it has no effect on the temp of the brew water at the puck. I've been running the test shots as long as 40 seconds & the brew water temp at the p/f never drops.

[Endo]

One interesting thing all the testing has shown is that when the temp lights are going off or flashing during a shot it has no effect on the temp of the brew water at the puck. I've been running the test shots as long as 40 seconds & the brew water temp at the p/f never drops.

That's good news. I was wondering about that.

On the subject of LED flashing: I couldn't figure why my first 2oz warming shot would drop the LEDs down 4C but the second 2oz warming shot only drops it about 1C. Strange considering where the sensor is located. In any case, I guess it doesn't really matter.

I'm looking forward to seeing some data logger Scace plots with different warm-up flushes.

[Richard]

I'm looking forward to seeing some data logger Scace plots with different warm-up flushes.

What is it about the temperature information in the VI Site and/or the VII Site (click at the top of the forum) that you find inadequate?

[ebprod]

After hours of using the Scace with my machine, I am still at +4. That is after 4 flushes, less than that I would be between +4 and +5, but for now I am leaving it at +4.

One interesting thing- I decided to drop my screens to inspect them while I was testing. Without the disc or screens the Scace reads 3c degrees higher. The disc must be doing quite a bit of buffering of the temperature. Wasn't there a thinner version of the disc at some point? It seems that would make a big difference in the offset.

-Joe

[JohnB]

All the U.S. V2 Vivaldis have come with the thinner block for some time now. How old is your machine?

Are you saying that you require 4 2oz flushes to reach your target temp?? Last night I was pretty much hitting it with the first flush, slightly over on the second & then leveling off on the next two. Haven't had time for testing yet today but I will recheck again tonight. Make sure you are getting a full 2-2.3 ounces through the Scace in 25 seconds. I have my pressure set between 8.75 & 9b with water flowing through the gauge so my V1 gauge reads .5 bar higher. With this setting I'm seeing 2oz out of the Scace in 25 sec. Set to a full 9b I would expect to see 2.3 oz pass through the Scace in that time. Weigh the water if you don't have anything more accurate then a measuring cup.

[ebprod]

I am doing the tests a couple of hours apart. If I follow Chris Coffee's procedure, my 3rd flush is right on. The second is about 1.5 low. If I wait for the light to stop blinking, then add 10 seconds, I get the same reading for each shot. Earlier I was getting more variation, but I was pretty sloppy with my timing between shots.

I will double check the volume of water through the Scace this afternoon.

-Joe

All the V2 Vivaldis have come with the thinner block for some time now. How old is your machine?

Are you saying that you require 4 2oz flushes to reach your target temp?? Last night I was pretty much hitting it with the first flush, slightly over on the second & then leveling off on the next two. Haven't had time for testing yet today but I will recheck again tonight. Make sure you are getting a full 2-2.3 ounces through the Scace in 25 seconds. I have my pressure set between 8.75 & 9b with water flowing through the gauge so my V1 gauge reads .5 bar higher. With this setting I'm seeing 2oz out of the Scace in 25 sec. Set to a full 9b I would expect to see 2.3 oz pass through the Scace in that time. Weigh the water if you don't have anything more accurate then a measuring cup.

[ebprod]

My machine is almost 2 years old.

Are you counting the water that comes out of the scace? Or are you including the water left over inside?

How would you clean a Scace? There is a knob on the end that is threaded (with the hole in it). Is that removable, and is that where you would clean it? The Scace belongs to Sakurama, I would hate to screw the thing up.

-Joe

All the V2 Vivaldis have come with the thinner block for some time now. How old is your machine?

Are you saying that you require 4 2oz flushes to reach your target temp?? Last night I was pretty much hitting it with the first flush, slightly over on the second & then leveling off on the next two. Haven't had time for testing yet today but I will recheck again tonight. Make sure you are getting a full 2-2.3 ounces through the Scace in 25 seconds. I have my pressure set between 8.75 & 9b with water flowing through the gauge so my V1 gauge reads .5 bar higher. With this setting I'm seeing 2oz out of the Scace in 25 sec. Set to a full 9b I would expect to see 2.3 oz pass through the Scace in that time. Weigh the water if you don't have anything more accurate then a measuring cup.

[JohnB]

My machine is almost 2 years old.

Are you counting the water that comes out of the scace? Or are you including the water left over inside?

How would you clean a Scace? There is a knob on the end that is threaded (with the hole in it). Is that removable, and is that where you would clean it? The Scace belongs to Sakurama, I would hate to screw the thing up.

-Joe

I'm measuring the water coming out of the Scace. To clean you would remove the lower cap you mentioned but you need to hold the upper section that screws into the Scace body with a wrench. I would talk to Sakurama to see how he feels about it before proceeding if you think it may be partially clogged.

[oton]

All the V2 Vivaldis have come with the thinner block for some time now.

My 3 months old MiniV2 comes with the thicker block.

One interesting thing- I decided to drop my screens to inspect them while I was testing. Without the disc or screens the Scace reads 3c degrees higher. The disc must be doing quite a bit of buffering of the temperature. Wasn't there a thinner version of the disc at some point? It seems that would make a big difference in the offset.

so, for temp estability which is better? the thinner or the thicker?

[chas]

I believe the thinner disks were a special request by Chris Coffee. LaSpaziale still uses the thicker disks in machines shipped elsewhere.

[JohnB]

[/quote]
My 3 months old MiniV2 comes with the thicker block.
[/quote]

Post corrected.

[JohnB]

I ended up staying at +3* after trying a +4* setting. This works well for the way I dose which is to pull a flush with the basket in the p/f, remove the basket & lock the p/f back in, dose/tamp & replace basket in the p/f. If I was doing a CC style dosing procedure with the P/F off for 30 seconds or more I might have to go to 4*. With the plus 3* setting I'm hitting my set temp after 22-25 seconds of the first flush. My second flush where I would be pulling the shots starts off close & hits it after 10 seconds holding steady throughout the rest of the flush/shot. Third flush will go .5*C high unless I leave the p/f off or wait longer between shots which is normally the case.

[ebprod]

The rented Scace is going back to Sakurama tomorrow. I would say that it is well worth the money to rent the Scace. After alot of testing, I found that my machine should be set between +3 and +4. Depending on how I ran the test I got results that were in-between those two numbers. In the end, I am leaving it at +3, because that is closer to what I got when I ran the test the way that Chris Coffee does it.

Something that was mentioned earlier. I was getting a little less water through the device during my first tests. I raised my brew pressure slightly and turned off the pre-infusion to get the water flow up to standards. It didn't seem to make any difference in my test results, although turning off the pre-infusion may have lowered my temperatures slightly.

When I originally got the machine from Chris Coffee (before upgrading the board) it was set at -1, so this is a dramatic adjustment.

-Joe

[JohnB]

Something that was mentioned earlier. I was getting a little less water through the device during my first tests. I raised my brew pressure slightly and turned off the pre-infusion to get the water flow up to standards. It didn't seem to make any difference in my test results, although turning off the pre-infusion may have lowered my temperatures slightly.

Sounds contradictory?? Less water/no difference, no p/i(less water)/lower temps. How much less did you get in the first tests?

[ebprod]

I was originally getting exactly 2oz. After adjusting the water pressure I was just a little bit over that amount. The instructions from this site for Chris Coffee's method says they program the button for two ounces.

Turning off the P/I may have raised the brew temperature slightly (lowered the offset). But it was such a small amount that I don't think it really matters.

-Joe

Sounds contradictory?? Less water/no difference, no p/i(less water)/lower temps. How much less did you get in the first tests?

[JohnB]

I was originally getting exactly 2oz. After adjusting the water pressure I was just a little bit over that amount. The instructions from this site for Chris Coffee's method says they program the button for two ounces.

Turning off the P/I may have raised the brew temperature slightly (lowered the offset). But it was such a small amount that I don't think it really matters.

It would be interesting to know why there is such a difference between the original CC settings & what we are ending up with. Makes me wonder if they weren't measuring the t type Scace with a k type meter as the differences are very similar to what Chas found when he changed meters.

[ebprod]

It can only be one of two things- Either Chris's measurements were wrong (unlikely?), or something has changed in the new boards. Has anyone actually approached Chris with this?

-Joe

It would be interesting to know why there is such a difference between the original CC settings & what we are ending up with. Makes me wonder if they weren't measuring the t type Scace with a k type meter as the differences are very similar to what Chas found when he changed meters.

[Endo]

It can only be one of two things- Either Chris's measurements were wrong (unlikely?), or something has changed in the new boards. Has anyone actually approached Chris with this?

-Joe

Why don't you e-mail them? I e-mailed both Chris Coffee and LaSpaziale about a problem I had with the fault logic on my Mini Vivaldi and got a reply from both.

I still think the hardwired offset was changed to give a default "zero" offset when the +ve offset became availalble. I suspect the machines were hardwired "hot" on the earlier version, when you're only option was a -ve offset.