Olympia Cremina Temperature Study, Part 2 - Page 4

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Chabeau
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#31: Post by Chabeau »

uscfroadie wrote:All of these have been spoken for now. I greatly underestimated the demand, so they went quick!

Does anyone have an idea where we can get a single strip instead of a pack of 10? I guess I could monitor the surface temps of 9 other things in the 60C-90C range.





No, that's crazy.
"The percolations are imminent."

-C.M. Burns, c.1996

mgwolf
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#32: Post by mgwolf »

I thought Orphanespresso sells strips like this.

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Chabeau
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#33: Post by Chabeau »

They sell strips that read from 90C to 120C. I'm looking for the 60C to 90C ones...
"The percolations are imminent."

-C.M. Burns, c.1996

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bostonbuzz
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#34: Post by bostonbuzz »

I thought I'd post some interesting findings, and a confession of my own stupidity.
I have been having routinely sour coffee since I got the thermometer attached, but this coincided with me fixing my channeling issue w/ dispersion screen fix. Everyone knows that a sour coffee is too cold (with some exception to coffees that are actually sour), but I resisted going to a higher temp. I tried going a bit hotter and didn't like the taste, but it turned out that I was so far off it didn't matter. FINALLY, I went up to the 190s start temp, and the sourness vanished (exact working start temps w/out sourness I'll figure out in time).

Some things I have noticed are the differential between the start temp and the final temp (erics' thermoeter stabilizes through shot at_). I pull all my shots at .75bar (bottom of the cycle).

172 start temp = 184 finish temp 12 degree difference
182 start temp =192 finish temp 10 degree difference
186 start temp = 194 finish temp 8 degree difference
190 start temp= 196 finish temp 6 degree difference
195 start temp = 199 finish temp 4 degree difference

The closer we get to 200f, the lower the final difference btw the start and end time. :D :shock:
This explains the stability of the Cremina.

Tekimono says that the starting temp is what he goes off of, but I'm starting to shoot for an END temp. Any ideas on the difference between the grouphead stable end temp, and the brew temp? At this point, the numbers have thrown me off and I'm going for taste, but what is the relation? Is it 1:1 as I expect?
LMWDP #353

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tekomino (original poster)
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#35: Post by tekomino (original poster) »

bostonbuzz wrote:Tekimono says that the starting temp is what he goes off of, but I'm starting to shoot for an END temp. Any ideas on the difference between the grouphead stable end temp, and the brew temp?
In my mind you have to co-relate and start with the temperature of group head when you start pulling a shot since that is only thing you have. I mean, how are you going to predict what end temp will be? For example on my machine if I start at 195 there is no way I would end up at 199. If I had boiler pressure really low, maybe, but I doubt it.

You should really investigate what is going on if you see start at 195 and end at 199. Something is not right.

My normal shots start at 175F end at ~192F.

But, the point is, you should experiment with what starting temperature works for you on your machine and boiler pressure setting and go with it :D You can start where I start and then adjust from there. For me starting at 175F-182F works fantastic.

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uscfroadie
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#36: Post by uscfroadie »

tekomino wrote:In my mind you have to co-relate and start with the temperature of group head when you start pulling a shot since that is only thing you have. I mean, how are you going to predict what end temp will be? For example on my machine if I start at 195 there is no way I would end up at 199. If I had boiler pressure really low, maybe, but I doubt it.

You should really investigate what is going on if you see start at 195 and end at 199. Something is not right.

My normal shots start at 175F end at ~192F.

But, the point is, you should experiment with what starting temperature works for you on your machine and boiler pressure setting and go with it :D You can start where I start and then adjust from there. For me starting at 175F-182F works fantastic.
So true! I start at the same temp on my 1985 model with similar results, but that's just a coincidence.
Merle

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uscfroadie
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#37: Post by uscfroadie »

Chabeau wrote:Does anyone have an idea where we can get a single strip instead of a pack of 10? I guess I could monitor the surface temps of 9 other things in the 60C-90C range.
Do what I did. Order a pack of 10 and give the others away. I kept two and mailed off the other 8 to other HB'ers. It's a whopping $10 for 10, so it's not as if you'll break the bank being a nice guy.

Click here

The part number for your desired range would be RLC-50-60/90-10 .

Just a thought...
Merle

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bostonbuzz
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#38: Post by bostonbuzz »

In my mind you have to co-relate and start with the temperature of group head when you start pulling a shot since that is only thing you have.
Certainly, I just meant using the end point as a target that you shoot for with the start temp/boiler settings. This is just a backwards was of saying that the end point MAY be indicative of the brew temp more than the start, since I've found that sometimes there is a discrepancy between where the start temp is and where the end temp should be (maybe my error).
You should really investigate what is going on if you see start at 195 and end at 199. Something is not right.
Indeed! My fault. I think the answer is simply that I have a 1/4" teflon thermal block! (I'd recommend 1/8" to others) When I came home today I took it out, thinking "I don't need this anymore, it just makes it harder to get to the 190s". Thinking things may be a little different, I pulled at 180 and it ended up around 197! (almost 10 degrees more than when the teflon was in) I affirmed the difference with a 190 shot which ended at 207.

It turns out, the thermal break plays an enormous role in the temp control during the shot, whereas I thought it just affected the idle temp. So far, and that's a big "so far", it means that my start temp needs to be much higher to get the same end temp as non-teflon-thermal-breaked Creminas, and it may even mean that our end temps don't correlate to the same brew temps.

Needless to say, I'm proceeding with finding my own numbers. I put the thermal break back in, and I'm sticking with it for stability sake. Currently, (about 8 shots in and subject to much change) I think 192-195 start, and around 200 end tastes the best.
LMWDP #353

IMAWriter
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#39: Post by IMAWriter »

erics wrote:From a non-Cremina owner, so take gently -

I believe you are using too much tape to hold the thermistor in place. I would recommend you clean the chosen surface with alcohol and use a 3/8" x 3/8" piece of tape. Tape has an effect on the heat transfer of the group to ambient.

The thermistor should be located on the cylindrical portion of the group at the "height" location shown in the instructions.

edit - high temperature 3M hook & loop is ~ 2 weeks away.
Eric, just received mine today! Beautiful "tinkering."

I can understand why the pictured tape job was done. Even after repeated alcohol cleanings, and new 3/8" aluminum tape ups, as the group gained heat, the tape loosened. no matter how I altered the position of the thermistor, same result.
Of course, i did warn you that certain tasks can befuddle me, so if you have any suggestions, I'm all ears. :)

IMAWriter
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#40: Post by IMAWriter »

tekomino wrote:In my mind you have to co-relate and start with the temperature of group head when you start pulling a shot since that is only thing you have. I mean, how are you going to predict what end temp will be? For example on my machine if I start at 195 there is no way I would end up at 199. If I had boiler pressure really low, maybe, but I doubt it.

You should really investigate what is going on if you see start at 195 and end at 199. Something is not right.

My normal shots start at 175F end at ~192F.

But, the point is, you should experiment with what starting temperature works for you on your machine and boiler pressure setting and go with it :D You can start where I start and then adjust from there. For me starting at 175F-182F works fantastic.
Denis, first let me say thanks for your investigative work!
I have a question. You say your end temp is around 192f. Wouldn't your shots (assuming you're not pulling straight monsooned Malabar) be on the sour side at that temperature?
Are you refereeing to the temperature reading on your thermometer at the conclusion of the pull? I would assume NOT the temperature of the shot in the cup.
We all have different stat settings, mine being .8/.95. I believe you're set significantly lower.

I guess I need to observe my machine, and see what's going on from the start of my pull to the bottom. The difference in start to end temps (as discussed by Bostonbuzz) should tell me (along with TASTE!) where I need to be. The FUN part will be keeping some logs of my different coffees, and maybe doing a chart.
Sheesh, back in school!! :lol:

I've been extremely pleased with my shots the past few years, as i've gotten to know Ms Cremina, but it's kind of neat actually seeing what's going on. I have OE's Penney temp strips, but I use it mainly to warn me when I'm "in the red."