Very interesting idea with mimicking the Pro profiles … not my thing, I think we still know too little about how the Home profiles work, so my focus is on that, but definitely interesting stuff to read about
hey, nice advice on the temp drop. I’m tasting some Nat Ethio DP and I thought about what you said, aeropressed at 91-92C, 20.4g in 150mL and bam! The blueberry train rolls agian
Cool … actually you can go way lower, it has huge impact (for espresso my experience is that half a degree is quite a difference, so working with temperature helps me achieve a taste profile I want)
For aeropress I think there are recipes with temperatures bellow 90 (i tried 88 myself, its very different )
I’m a bit behind with my posts, so some quotes and question/answers
funny, never heard of it, I’ll have a look (edit: ah ok its a variant on the poor-over. Looks nice!). This weekend I used the V60 again but the ‘general’ method doesn’t appeal to me (it results in a really weak coffee). Anyway using that method, the acidity was nearly gone, what was left of it was pleasant giving the coffee a somewhat ‘floral’ taste. However as said I really need to fine tune the V60 method to my likings.
- A Cellini Rocket (ECM), modified with thermometer in the group. Note that I’ve been pulling shots for years now and unless you have a 15k machine its nigh impossible to have constant temp output it will ALWAYS fluctuate and I’m aware of T-surfing and doing this correctly I can get 10-15s of stable output @my goal T but as I pull shots ~30s… It really helps though to have a Thermo in the group as then you actually see what the water T is just before it hits the grounds. Anyway, yes 96C is crazy high, but it got the acidity out…but leaving a rather flat taste. Note thought that in my experience lowering the T has a far bigger impact than highering(?!?) the T. E.g. 92 vs 93C has a far bigger impact than 94 vs 93C, but that’s my experience. (That said: 96C is still crazy high, but I like to xperiment).
- 10h post roast is what I did too, but the result was still (roughly) the same
- I’m familiar with nitro-flushing, but not in the context you’re placing it in. What I know is that its used to flush out the O2 before sealing the coffee (professionally), mainly because N2 is far more stable/inert than O2. But what do you mean?
Well … the Nitro Flush I mentioned is the one used by one of the competitors on this years worlds I think. Its been linked here too, thats why I though most of us have seen it (because the person roasted on Ikawa right there and made the competition shots from a totally fresh roast straight from the roaster.
You take your ISI bottle (cream bottle …) you grind your coffee, put it in (I guess you can grind two doubles or maybe more …) use the NO cartridge like for whipped cream, just wait for a moment, carefully release the pressure and remove the grounds … this should get rid of a lot of CO2 in the coffee. I have tried it and I could make espresso straight from the roaster too, and it was quite satisfying experience (though I dont want to use one cartridge every time I make espresso so I dont use it regularly …)
The Rocket is a good machine, and with the modification you mentioned, sure the problem is not to in the machine. But as I wrote, we usually make espresso for samples I do on a LaMarzocco/MazzerMini like 10h posto roasts, without too much fiddling with the grinder (so I thinkthere is not huge difference in the grind otherwise it would be impossible to hit a correct extraction in 44g sample which gives you just one second try :)) and I do not remember any of those shots being overly sour … usually its quite what we expect it to be.
True that lowering the temperature has more impact … thats why my extractions live around 91C (maybe even a bit less, I have no means to measure extraction temperature, so if the water going into the puck is 91-92 … the extraction could happen even bellow 90C for some time ) and only when I need to compensate and ballance the taste in a way I know will work with higher temperature I go above 93C.
It is just really interesting to me to understand what causes your extraction to be as sour as you described it at normal temperature and time and ratio parameters (so I could suspect the grind, as you described going for rougher grind, but you should not have underextraction due to the grind if the time is right … so… it makes think hard really, because sometimes I would really like to have the acidity go way up, and usually I go a little lower on temperature, have the shot go a little faster for a bit of underextraction, but without a gusher shot that would go under 10s I just can not get the acidity into a territory that you described … so thats why I try to understand …
Regarding the V60 … there is so much you can tune, so you should be able to get extraction that would satisfy you in the limits of the method (well you dont get so much mouthfeel and body with paper filters but you can try metal filter there too).
I like it a lot, since it plain works for me … and I like fiddling with the parameters and getting different brews out of it :))
ok…that is getting dangerously close to ‘over the top’ and I’m a person who goes as far as buying his personal coffee roaster (which is ‘far out there’ for most people, including coffee connoisseurs)…but cool! Interesting trick.
Well perhaps I wasn’t entirely clear, I usually get a bit of a higher acidity with a fresh roast but this ‘acid bath’ was mainly caused by the profile I posted (which was mimicking the pro). Apparently the brazilian coffee & that profile & ‘only’ 10 h rest & a ‘normal’ extraction method delivered such a sour taste.
Has it improved any since?
Btw. The Bonavita immersion brewer is very like a clever dripper except made from porcelain and you open/close the valve by a lever.
I roasted the Ikawa Sito Brazilian on a slightly lower profile trying for 1C at 6:45. It gave a very light roast, borderline under with moisture loss of 11.46%. No obvious cracks were heard. However, on Day 3 post roast it is tasting really nice. Very smooth and sweet with a creamy body and buttery mouthfeel. Hints of a little orange acidity. I like this better than the Ikawa profile but if you don’t like light roasts…
I’ve also roasted another Burundi on a lower profile than the one I posted aiming for 1C at 5:15. It hit 1C at 4:55 to 5:55. Moisture loss of 13.18%. Day 1 brew was super fruity and sweet, Day 2 less so.
Ah … I see … did not understand it that way … I though it due to freshness and extraction.
Regarding the Nitro flush … I would say, just try it, and you will see, if it is worth doing it. For me, I dont mind waiting to next day … so … I would do it only if I want to iterate on the roast the same day and so I need to taste the current profile, or for some coffee that has a special characteristics that make it the best right after roast for some reason (I think there are some candidates for that) or … just to try something different from time to time … the total fresh from roaster taste profile is very interesting though sometimes very far from rounded
when i get the chance I surely will, if not only for the experiment.
One question though. From what I’ve read the CO2 delivers a ‘push back’ to the group, causing a slower/thinner flow of water through the ground which causes underextraction. I’ve always had a bit of problems with that assumption, but I haven’t been able to properly test it.
However after you nitro-flush is your water flow through the ground then stronger/thicker/bigger?
(Which would corroborate that assumption).
I dont think that assuption is correct. From our experience a too fresh after roast has usually a tendency to go fast, rather than slow. I did not expect ever to have a very slow extraction with a normal grinder setting and extremely fresh beans.
I had some gushers from the fresh coffee, but not allways.
What it probably does is, that the CO2 bubbles out in the group head, so only maybe if this has a chance of making a way more pressure in the head could it tamp the puck way more by hydraulic pressure and cause slow running shot. On the other hand if this does not happen I think what happens is that the bubbles make the puck more loose and open canals for a fast running shot.
The first version I did not ever noticed, but I know it might tamp the puck since its something that I use to my advantage sometimes. When I notice I get some drips in preinfusion (meaning I did not grind correctly and the shout would run fast) I do a fast step to 9-10 bar from 0,5bar preinfusion (like fraction of a second fast) effectively tamping the puck with the water and slowing the shot this way (I do not like dumping a shot so I do all I can to save and drink it :))
Interesting. So far with fresh roasts I have had quite an under extracted pull (mainly because after ~30s I had 15~20 ml of my usual 50-60ml. ) In short a fresh roast runs really slow. But I’ve not been able to properly test this with e.g. a week old roast AND even then I’ would not be fully convinced if the difference was noticeable, because of other factors. Flushing it however might actually narrow it down to the CO2 factor (IF there is such a thing!).
And what is your shot profile? (I do as a standard a 10s 0,5bar preinfusion, then relatively slow rise to maximum pressure, with expected drips at 4 bar +/- … and I keep it there till the end) I have a completely different gear, but I dont think that would be able to cause so much difference, so I think the sequence of steps will steer the effect of the freshness maybe.
From what I can see (I have a pressure gauge on the brewing head) there is no rise in pressure in the preinfusion, I let it go to 0,5bar and I close the valve, so its slowly going down as the water is infused into the puck … if there would be some pressure buildup from the CO2 I should see it no dropping or maybe rising, but it behaves as usuall.
err … by the way … how much force you use for tamping?
Do you have a naked portafilter? It might be interesting to shoot a video of the shot with naked.
well I’ve installed a pressure gage on a portafilter once to check the build up pressur which (IRC) was 12 bar, but pressure won’t get as high in a non-closed system. There is however no way to check for me.
Pre-infusion goes automatically and is ~3s fill ~3s still and then 30s pull.
its possible that it is indeed an unchecked myth, but your findings don’t convince me fully, there are simply too many variables. To eliminate one is to repeat the process (exactly) nitro flushed and one not nitio flushed and THEN check the differences.
(answer: ~12kg) funny thing that I read and hear a lot about tamping, the pressure, the eveness, the polishing the NSWE pressure points etc etc etc. And then I read an article about two barista who wanted to find out whether there really was a noticeable difference between tamping forces (and eveness and polishing). The outcome; save for the fact that some measure of tamping must be applied (so there IS a difference between untamped and tamped) there was NO discernible difference. But as I got the 12kg in my system, I just keep applying it.
Note though that when I occasionally do a naked pull I do pay a lot attention to tamping as its vital to get a clean shot.
(and that answers your last question as well! Nice thought, I’ll shoot some vids with fresh roast and week old roast with same profile!
Ok, so a standart tamping force. I am aware of those findings, my reason to ask about tamping force is that I think the CO2 can have a different effects with different tamping styles. I for example do tamp lightly, so there is a lot of change I get when I use that pressure shock that adds more tamping to the puck. But if I tamped with a lot of force (like 20+) my experience is that the puck starts to be fragile and may crack when i do the same, and it adds almost nothing in the slowing of the shot. So i eould guess the effect of co2 bubbles in the puck migh have a very different outcome with a light and hard tamp.
Guys. This is getting way off topic. Any chance you can create a new thread in gear & gadgets to discuss espresso extractions for fresh coffee? It would make more sense.
Sure … I am sorry Stephen, have forgotten what thread are we in.
No worries Pavel. Perhaps @Geoff_IKAWA could move the espresso discussion? A lot of interesting posts deserving of its own thread. It will make finding it again much easier.
That would be perfect … i think we can not move them ourselves.