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Boffin thread ( ek43, refracting, pressure profiling, ; other guff)

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for me at least don't read anything into a subjective statement about more boulders than expected, better wording would be more like I'm surprised that's what an EK grind distribution looks like based on a sample size of 1.

 

as I've said elsewhere I'd like to do some test grinds and sieve them to get an idea of how distribution changes over the range. I'm hoping others might do the same so we can compare burrs and effect of alignment - for no other reason than it's geeky (and it might encourage me to align better)


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for me at least don't read anything into a subjective statement about more boulders than expected, better wording would be more like I'm surprised that's what an EK grind distribution looks like based on a sample size of 1.

 

as I've said elsewhere I'd like to do some test grinds and sieve them to get an idea of how distribution changes over the range. I'm hoping others might do the same so we can compare burrs and effect of alignment - for no other reason than it's geeky (and it might encourage me to align better)

 

Yeah, we'd be happy to try to run some little experiments if people have suggestions around what would be useful. We've only just started scratching the surface with the sieves but I'm already thinking that the grind size choice is going to be important. I guess we really want to find an optimum grind size, coupled with the right sieve sizes and then adjust recipes and or doses accordingly. The last few brews I've done, I've not been able to get the EY to register i.e it's over 26% and too strong (1.4 tds from memory with a 9g dose on the Perger method V60). That's using the 400 and 800 sieves.

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On the EK you have to go way finer than your normal drip setting in order to get an even split between 400/800 sieves. I did some tests using a single sieve to try and get 50% under and 50% on top (this is apparently finding the median size). Results were:

 

11 - 1000um - 82.4% through

11 - 800um - 48.4% through

 

9 - 1000um - 90% through

9 - 800um - 61% through

9 - 600um - 33% through

 

7 - 1000um - 94% through

7 - 800um - 84% through

7 - 600um - 51% through

 

All grind settings are on the Callum dial. Going by those figures, if you want to sieve at 400/800 then you would pick 600 as your target median grind size and grind at setting 7. Like I said - way finer than a normal drip (unless I've been doing totally wrong!). Happy to be corrected on this theory @MWJB :)

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Yeah, we'd be happy to try to run some little experiments if people have suggestions around what would be useful. We've only just started scratching the surface with the sieves but I'm already thinking that the grind size choice is going to be important. I guess we really want to find an optimum grind size, coupled with the right sieve sizes and then adjust recipes and or doses accordingly. The last few brews I've done, I've not been able to get the EY to register i.e it's over 26% and too strong (1.4 tds from memory with a 9g dose on the Perger method V60). That's using the 400 and 800 sieves.

 

9g to 200g? 45g/L? Sounds low, maybe try 11 or 11.5g?

 

Maybe start with 350/400 bottom & 1000/1100 top, then adjust grind setting until you have about 15% either side of the sieves, reducing top sieve & increasing bottom as necessary? For a given sieve set you might get 70% between them at a fine setting for that set & more small particles, fewer big. As you go coarser with the same set, small & big will even up until big overtakes small & % between sieves will drop.

 

Not an EK, but something like this...

Kruve%20Lido%20158%200.5%200.63%200.75%20non%20log_zpsweto8whb.jpg[/url]

@Phobic I'd be surprised, but pleasantly so, if the Kruve can provide resolution enough to differentiate between good & nominal alignment.


“Coffee evokes the most insane reactions in people”, Rene Redzepi.

 

https://markwjburness.wordpress.com/

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Yeah, we'd be happy to try to run some little experiments if people have suggestions around what would be useful. We've only just started scratching the surface with the sieves but I'm already thinking that the grind size choice is going to be important. I guess we really want to find an optimum grind size, coupled with the right sieve sizes and then adjust recipes and or doses accordingly. The last few brews I've done, I've not been able to get the EY to register i.e it's over 26% and too strong (1.4 tds from memory with a 9g dose on the Perger method V60). That's using the 400 and 800 sieves.

 

I can see why you're getting huge EYs if you're brewing at 9g/200g. I imagine you're doing this to keep TDS in check? Why not brew at a more "normal" ratio and dilute?

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I can see why you're getting huge EYs if you're brewing at 9g/200g. I imagine you're doing this to keep TDS in check? Why not brew at a more "normal" ratio and dilute?

 

Yeah, that's exactly what we ended up doing.

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9g to 200g? 45g/L? Sounds low, maybe try 11 or 11.5g?

 

Maybe start with 350/400 bottom & 1000/1100 top, then adjust grind setting until you have about 15% either side of the sieves, reducing top sieve & increasing bottom as necessary? For a given sieve set you might get 70% between them at a fine setting for that set & more small particles, fewer big. As you go coarser with the same set, small & big will even up until big overtakes small & % between sieves will drop.

 

Not an EK, but something like this...

Kruve%20Lido%20158%200.5%200.63%200.75%20non%20log_zpsweto8whb.jpg[/url]

@Phobic I'd be surprised, but pleasantly so, if the Kruve can provide resolution enough to differentiate between good & nominal alignment.

 

As usual your posts will take me a little while to digest (a compliment which may not sound like one). Thanks for taking the time to share your ideas, I'm sure I'll be working through the suggestions.

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for me at least don't read anything into a subjective statement about more boulders than expected, better wording would be more like I'm surprised that's what an EK grind distribution looks like based on a sample size of 1.

 

as I've said elsewhere I'd like to do some test grinds and sieve them to get an idea of how distribution changes over the range. I'm hoping others might do the same so we can compare burrs and effect of alignment - for no other reason than it's geeky (and it might encourage me to align better)

If you're referring to my post then I presumed you'd sieved an ek grind based on the words you used and was genuinely interested in your results....

 

I've just purchased a kruve and was interested to have something to compare to.


DE1Pro, EK43 SSP, bloody tasty coffee!

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@Phobic I'd be surprised, but pleasantly so, if the Kruve can provide resolution enough to differentiate between good & nominal alignment.

 

I'll bow to your wisdom as you have a much better grasp of these things than me! :) I was vainly hoping that being able to measure to 0.1g accuracy of "boulders" in the 1100 sieve at grind setting 12 might allow us to see some coarse correlation between EKs, but confess I don't have an intuitive feel for what's realistic.


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If you're referring to my post then I presumed you'd sieved an ek grind based on the words you used and was genuinely interested in your results....

 

I've just purchased a kruve and was interested to have something to compare to.

 

happy to share any results, it was literally my 1st grind though and I didn't record any data, it's on my to do list :) will share when I get round to it, hopefully this weekend.

 

it was more that I remembered being surprised at what I saw but that's not really a good basis for comparison :D


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I'll bow to your wisdom as you have a much better grasp of these things than me! :) I was vainly hoping that being able to measure to 0.1g accuracy of "boulders" in the 1100 sieve at grind setting 12 might allow us to see some coarse correlation between EKs, but confess I don't have an intuitive feel for what's realistic.

 

Well, you can no doubt weigh to 0.01g resolution (I do) & maybe do 3 tests to get a reasonable average, but EK alignment seems to be more an issue at the finer end & for espresso settings. Given that the average grind size in this case is probably around the smallest sieves you have (~200-250) and that static is going interfere with getting clean results (even sieving an average grind of ~500um determined with a mesh sieve, I had dust all the way through the Kruve with a 200 on the bottom), so even if you determine your average grind size, getting down to the nitty gritty of the distribution at lower values than that, is going to be impossible. It's not really what the Kruve was intended for, more of a brewing aid than a fine tolerance analytical tool (though for coarser than espresso grind settings, it does allow reasonable comparisons).

 

For drip? I don't know, I haven't seen any analysis for the EK at the coarser end, I'm not sure that there is much acceptance that behaves as differently in that region compared to typical grinders?

 

I guess if you did want to pursue this (I'd be interested in what you found as much as anyone, so don't feel I'm trying to put you off, more suggesting what might be a more realistic use of your time) I'd dial the grinder in for a given recipe, sieve a few samples taking out the top fraction only & to see how repeatable. Then try alignment & repeat & see what difference you have?


“Coffee evokes the most insane reactions in people”, Rene Redzepi.

 

https://markwjburness.wordpress.com/

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thanks for explaining Mark, i'd not really thought about it in that way but that makes a lot of sense.

 

I was actually planning on doing some testing at the coarser end mainly to understand what the effect of regrinding is. My thinking being that sieving is a real PITA, I want to avoid doing it as it takes too long and is too messy, right now I can see a benefit in sieving & regrinding the boulders, so what if I just regrind everything without sieving? That way I can keep at the coarse end (~17 on the 3FE for CDD) which minimizes fines production but produces more boulders, but use the same setting to reduce the boulders by regrinding - best of both worlds maybe? Right now I'm finding that I need to grind finer than I normally would to make the sieves + boulder regrinding viable.

 

This is going to reduce the boulders overall and I'd expect an increase in fines, however I'd hope the fines would increase only slightly compared to the boulder reduction - in my mind I'm thinking fines production will be greater from whole beans than from boulders at the same grind setting.

 

the resulting ground coffee hopefully will have a better proportion of fines:ideal:boulders without the need to sieve. Something that will easily & quickly fit into the work flow with minimal fuss and mess.

 

I'll use the sieves to measure the output by splitting the grinds out each time I grind and weighing what's at each level before recombining everything, mixing, and regrinding. Then sieve and weigh the outputs to see what the regrind did, rinse and repeat until the boulders are within an acceptable place, then look at the affect on the fines:ideal:boulders distribution.

 

The accuracy of the Kruve might not be there to draw real scientific conclusions but I'd hope it should be indicative of what's going on - let's hope the result tastes good!

 

any thoughts?

Edited by Phobic

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Does a lot of the ground coffee not get stuck on its way to the burrs if you try and regrind with the EK?


Home: Sage Dual Boiler, Probat EK43 & Feldgind

Work: Sage Dual Boiler & Niche Zero

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yes it does.

 

I've been using a camera blower to push it through, works very well.


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thanks for explaining Mark, i'd not really thought about it in that way but that makes a lot of sense.

 

I was actually planning on doing some testing at the coarser end mainly to understand what the effect of regrinding is. My thinking being that sieving is a real PITA, I want to avoid doing it as it takes too long and is too messy, right now I can see a benefit in sieving & regrinding the boulders, so what if I just regrind everything without sieving? That way I can keep at the coarse end (~17 on the 3FE for CDD) which minimizes fines production but produces more boulders, but use the same setting to reduce the boulders by regrinding - best of both worlds maybe? Right now I'm finding that I need to grind finer than I normally would to make the sieves + boulder regrinding viable.

 

This is going to reduce the boulders overall and I'd expect an increase in fines, however I'd hope the fines would increase only slightly compared to the boulder reduction - in my mind I'm thinking fines production will be greater from whole beans than from boulders at the same grind setting.

 

the resulting ground coffee hopefully will have a better proportion of fines:ideal:boulders without the need to sieve. Something that will easily & quickly fit into the work flow with minimal fuss and mess.

 

I'll use the sieves to measure the output by splitting the grinds out each time I grind and weighing what's at each level before recombining everything, mixing, and regrinding. Then sieve and weigh the outputs to see what the regrind did, rinse and repeat until the boulders are within an acceptable place, then look at the affect on the fines:ideal:boulders distribution.

 

The accuracy of the Kruve might not be there to draw real scientific conclusions but I'd hope it should be indicative of what's going on - let's hope the result tastes good!

 

any thoughts?

 

The CCD is an immersion brewer, I'd grind fine enough (reducing boulders without regrinding) to hit the extraction you want & sieve out the bottom 15% or so. Regrinding is probably easier in a gravity fed, rather than auger fed, grinder. 17 on the dial sounds pretty coarse, I don't have much experience of grinding coarse for a CCD brew, so can't really comment on what you might be aiming for.

 

I aim to sieve out the largest component for drip (keeping fines to control flow) and sieve out the fines (or both fines & boulders if losses are low enough) for immersion. I only regrind (conical hand grinder) if I have a grinder that leaves more than 15-20% above the 1100 sieve at its finest useable setting.

 

Sieving out the boulders only reduces your average grind size (makes everything that is left finer), lifts extraction and allows a sweeter brew. Sieving out fines only reduces undissolved solids & silt that make it into the cup but does not reduce your average grind size with respect to 0um, it just narrows the particle spread. So if your largest particles are between say 500 & 1000 with 15% over 1000, taking out the


“Coffee evokes the most insane reactions in people”, Rene Redzepi.

 

https://markwjburness.wordpress.com/

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17 is very coarse, it's not really about CCD, just using that as an example grind size to illustrate the point of going coarser to achieve a lower average grind size without increasing fines too much.

 

will have a play if I get chance and see what it's like, I think the biggest problem will be regrinding in the EK though.


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I have kindly been given a QM Verona on loan for a short while and thought I would explore the world of low pressure.

 

Question for the boffins: What differences should I expect when lowering pressure? Anything at all - both qualitative and quantitative.

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I have kindly been given a QM Verona on loan for a short while and thought I would explore the world of low pressure.

 

Question for the boffins: What differences should I expect when lowering pressure? Anything at all - both qualitative and quantitative.

Lower than 7bar, I'd expect to be looking at slightly longer than usual shots and you may have to drop your temp by a °C or so. I've seen a massive drop in channelled shots at 5bar (maybe 1 in 50) and a huge difference in the cup.


'it's all about the microbubbubbles'

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Lower than 7bar, I'd expect to be looking at slightly longer than usual shots and you may have to drop your temp by a °C or so. I've seen a massive drop in channelled shots at 5bar (maybe 1 in 50) and a huge difference in the cup.

 

Thanks. Drop temperature to account for longer contact time?

 

Do you run largely the same recipes 6bar vs 9bar? I noticed that Maxwell CD has dropped dose since going low pressure.

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Thanks. Drop temperature to account for longer contact time?

 

Do you run largely the same recipes 6bar vs 9bar? I noticed that Maxwell CD has dropped dose since going low pressure.

At 5bar, midweek I run (with current blend) 18-37 in about 35+ seconds at 93°c. Weekends I drop that time to sub-30sec shots for speed of service. I've had our blend roasted to work well with both lots of contact times though.


'it's all about the microbubbubbles'

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Temp will vary on the machine used , an e61, i would have thought will drop temp the longer it is on , as opposed to Scotfords which will be more stable .


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Temp will vary on the machine used , an e61, i would have thought will drop temp the longer it is on , as opposed to Scotfords which will be more stable .

This. Forgot to say that, I'd look into the temp stability of your machine over 30-60sec shots if you're planning on this long and slow lark


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