Great first extraction..second is runnier?

[alsterling]

I run Malabar Gold as my prime blend; plenty of crema, and I usually set the Macap stepless for a tighter grind than any other blend. When I'm doing 2 or 3 extractions in a row, the first one after the machine has been sitting awhile is excellent. My cappuccinos take about 4-5 minutes total to make. So after I've totally cleaned my workspace from the first one, and all the lights are showing full heat recovery, my second extraction always seems to be a little runnier; not as thick? Why would the first be excellent and the second, etc., runnier? The only thing I can figure is that my machine really isn't as hot as when first used. BTW, I grind per shot, and never pre-grind for a series.

[Niko]

Sounds like your first shots have a little residue from the day before (more density and moisture built up) so the shots have a slower pour. If the grinder sat around for more than 24 hrs, a small pinch full of beans easily remedies this by shooting some through. Of course sometimes it requires a whole double blank shot through but you won't find me wasting good beans like that
Sometimes I'll run my first shot of the day through and then adjust the grind slightly tighter for the following shots. As the day progresses, the grind will go tighter for the late afternoon and then back to where I started for the next morning. It's a constant game with the grinder that I do in my sleep.
....and of the course there are the lazy days where I don't touch the grinder and just deal with the slower and faster pours.

[alsterling]

Niko.....hello. I really should shoot another video at my bar prepping and running a shot. It would probably set up my question a bit better. Actually, I grind fresh for each shot, and brush out the chute/channel each time till it's empty of residue. If anything, the first shot, I'd think, if there were residual grounds, would suffer to the runny side. But assuming that my grinder starts clean each time, it's the followup shots that go runnier. And I do tighten the grind a bit, but it really doesn't change the characteristics of the flow. The followup shots are OK, but never as thick as the first. I'm going to check this again, but I believe , from memory, that giving the machine a bit longer to recover, say an extra 5 minutes, yields thicker extractions. I'm wondering if it has something to do with the higher temp's of a machine, which certainly includes the brewgroup and PF? It's not a debilitating issue, but makes me wonder about the consistency of my machine.

[JohnB]

Even if its only been a couple minutes I pull a warm up flush while I'm weighing out the next batch of beans. At 5-6 minutes I would definitely expect the g/h to have cooled down but I don't know if that would cause your problem.

[alsterling]

Interesting point about a "warm up flush", which now confuses me, as I thought that maybe the machine cools down after my extraction, and the extra time between extractions allows the machine to "warm up", as opposed to doing a flush that might actually rob the machine of temperature? I was sorta' hoping that someone had noticed the same thing on their machine. I am running it on a 120 vac line, and have been holding off running the 220vac over to my bar, which I really need to do for other reasons. I was thinking that going to a split leg off the 220vac line from the laundry, just off the garage, would guarantee a full 20amp line which might insure min. recovery times, etc.

[JohnB]

Why would the machine cool down after pulling a shot? The brew boiler is going to kick in & bring the boiler temp back up. The g/h cools off because its hanging out in the breeze & is a non saturated design. After the initial 30+ minute warm up I always start off with a couple warming flushes before the first shot to get the b/h up to temp.

Are you running in 20A mode now?

[alsterling]

Good question. Why would the machine cool down after an extraction? My curiousity is based on coming to the machine after it's been idle, and then getting a great extraction.....but having a followup extraction that runs thinner and blonder? That's why I'm asking. I don't know. As for the current power option; yes, I'm running on a 120 vac line and have the machine set for a 20amp circuit. Both boilers operate at-will. I'm mentally trying to isolate the variables that might cause the change. Maybe the machine is actually "hotter" on the second extraction, not cooler.

I do an extrended flush and jiggle on the PF during cleanup. But I never run the second shot until all led's are back to fully lit.

[JohnB]

I do an extrended flush and jiggle on the PF during cleanup. But I never run the second shot until all led's are back to fully lit.

Are you using pre infusion? Do you pull a warm up flush before pulling that first shot?

[chas]

Everything I have seen using the Scace is in agreement with your observation that the shots warm up.

I did some measurements yesterday. I don't even remember now what possessed me to do it other than it's been quite a while. At first I was scratching my head over the strange readings until I realized that the Fluke was giving me a low battery reading.

Since I haven't put it away yet (wife in Guatemala for 2 weeks, so why bother !), I'll take some measurements tomorrow morning.

All my previous recorded measurements ignored the warm up shots since I was looking for long term stability. However, I'll put in the Scace and let it warm up for 15-20min, then I'll record each pull without doing any flushes first so you can see how many shots it takes to stabilize and what the temp range is over those shots. From what I remember even though I never wrote it down in the past: 1st flush is 2-4C low, 2nd flush is 1-2C low, and third shot starts 0.5-1C low but comes up to set temp by mid-shot.

BTW: wife is instructed to bring back as much coffee as she can. Hotel and airport gift shop coffee not allowed. She's going to be in the Antigua area for 4 days, so hopes are high for some good stuff.

Al, do they let you bring coffee back in to the US? I know sometimes they are conservative about importing agricultural products due to the possibility of spreading diseases to local crops. However, there isn't much "local" coffee grown in Maryland!

[Niko]

Guatemala huh?
Nice.

Hi Al, reason I mentioned grinds was because no matter how much you brush out a grinder - there's always some left behind. I use doserless grinders and some stay in the burrs and on the Mazzer some stay way up in the chute (just enough to slow down my first shot of the day).

And Chas, do tell about the Guatemalans your wife brings back. We're talking about coffee, right? - Not people ...

[Weska]

One more possibility, alsterling, is that there is moisture clinging in your portafilter somewhere.

Do you wipe dry after each extraction? If not, then the moisture at the edges or underside of the filter basket can create channeling by a sort of differential pre-infusion. (If it's already wet in some places, the pumped water will have an easier time negotiating passage there than elsewhere in your puck where the coffee is completely dry.)

[alsterling]

I do an extrended flush and jiggle on the PF during cleanup. But I never run the second shot until all led's are back to fully lit.

Are you using pre infusion? Do you pull a warm up flush before pulling that first shot?

No...I haven't purchased the pre-infusion attachment, although I thought about it. And no, I don't pull a warm up shot because the first shot is spot on. That's why I'm confused. If I use the machine right off, then from what you're all saying, my machine is changing extraction characteristics because it's running "cooler" on the second shot. But remember the jiggle and clean on the PF? I've programmed the single shot button for my extractions and the double button to run extra long for cleaning. So my clean up flush and jiggle should, in essence, be what you guys call the "warm up" flush.

[alsterling]

.............BTW: wife is instructed to bring back as much coffee as she can. Hotel and airport gift shop coffee not allowed. She's going to be in the Antigua area for 4 days, so hopes are high for some good stuff. Al, do they let you bring coffee back in to the US? I know sometimes they are coffee about importing agricultural products due to the possibility of spreading diseases to local crops. However, there isn't much "local" coffee grown in Maryland!

Chas....when we go back to Brasil, we almost always travel from Brasilia, DF, through Goias, (more family), on to MInas. We are either going to Uberlandia, one of the cities where we have allot of family, or traveling to the Southeast to Sul de Minas. In both directions, we stop at favorite mercados in small towns, especially in Sul de Minas, and buy local brands of Brasilian coffee. We always bring back "pre packaged" roasted and ground Brasilian coffee. We also bring back cheeses from the farm, and definitely bring back a couple bottles of Cachaca, or sugar cane rum as it is sometimes called. I've not brought back green beans, but our friends living in Laguna Niguel here in OC, have a family coffee fazenda/farm just outside of Carmo de Minas, (famous for the 2005 C of E $50 plus coffee). They bring back green every now and then. However, it's easier, believe it or not, to simply have a relative send a special SO to me from a friends fazenda, in small quantities, or just order here on the West coast from a local importer/broker.

[alsterling]

One more possibility, alsterling, is that there is moisture clinging in your portafilter somewhere. Do you wipe dry after each extraction? If not, then the moisture at the edges or underside of the filter basket can create channeling by a sort of differential pre-infusion. (If it's already wet in some places, the pumped water will have an easier time negotiating passage there than elsewhere in your puck where the coffee is completely dry.)

Yes...I both dry the basket and tap the PF to get water out of the bottom of the PF. Good point. To be more expeditious on this issue, I really think I'm going to have to make a short video to show exactly what's up. I can do a "private post" with a link, on youtube. Hopefully this weekend I'll have an hour or so to do that and would definitely appreciate feedback. (.........just don't critique my "wall art", OK?)

Al's Espresso Bar_email insert.jpg (261.39 KiB) Viewed 22509 times

[JohnB]

No...I haven't purchased the pre-infusion attachment, although I thought about it. And no, I don't pull a warm up shot because the first shot is spot on. That's why I'm confused. If I use the machine right off, then from what you're all saying, my machine is changing extraction characteristics because it's running "cooler" on the second shot. But remember the jiggle and clean on the PF? I've programmed the single shot button for my extractions and the double button to run extra long for cleaning. So my clean up flush and jiggle should, in essence, be what you guys call the "warm up" flush.

If you aren't pulling any warming shots then there is no telling where your first shot temp really is. The water in the boiler may be hotter then indicated after a long idle period & your grouphead/portafilter is definitely on the cool side.

Try this: Let the machine fully warm up, pull 2 2-3 oz warming flushes with the p/f locked in with full recovery between each while you grind the beans, then load & pull your first shot. My guess is this will be like your 2 & 3rd shots. Adjust your grind a little tighter until the issues clear up. This is how you should be pulling your first shot if you expect the brew temp to be accurate. You need to wake up the boiler with a flush to get an accurate temp after an idle period, you can't just go by the lights.

[alsterling]

....Try this: Let the machine fully warm up, pull 2 2-3 oz warming flushes with the p/f locked in with full recovery between each while you grind the beans, then load & pull your first shot. My guess is this will be like your 2 & 3rd shots. Adjust your grind a little tighter until the issues clear up. This is how you should be pulling your first shot if you expect the brew temp to be accurate. You need to wake up the boiler with a flush to get an accurate temp after an idle period, you can't just go by the lights.

John...thanks for that. That will certainly give me a base starting point that I can adjust to. I just got up and will go downstairs and see what happens.

[JohnB]

Thinking about what I've seen with my machine I'd have to guess that the brew boiler temp is lower then what is indicated by the lights after a long idle period. You'll note that you will see your longest recovery period after the first flush with most if not all lights going out before the temp goes back up. Recovery after the second flush is much quicker as the temp is back up close to what is indicated.

If you were happy with the taste of your first shot with no warming flushes then you will probably end up using a lower brew temp setting for the same coffee when you start pulling shots after flushing.

[chas]

OK, here are the temp measurements I took with and without preinfusion.

Intrashot Temperature Stability

S1V2TempStability.jpg (137.32 KiB) Viewed 22464 times

[JohnB]

I would think that the p/i water would be cooler as most if not all of it sits in the pipeline between the boiler & g/h outlet cooling down between shots. Notice how long it takes to "prime" this pipeline with boiler water when you pull your first warming flush after a long idle period when using p/i. Nothing comes out of the g/h for several seconds or longer. Once primed that water sits there & heat is drawn off by the metal surrounding it so your p/i water will be cooler then water pushed out of the boiler by the pump during a shot..

[chas]

Uh oh! The last couple of days my shots have been noticeably tastier and I have been roasting the same batch of beans for the last few weeks. Then I realized that after doing the Scace tests last Sunday I forgot to turn preinfusion back on. I guess I'll better try two shots back to back later with and w/o PI and see if I am imagining things!

[alsterling]

Uh oh! The last couple of days that all my shots have been noticeably tastier that usual and I have been roasting the same batch of beans for the last few weeks. Then I realized that after doing the Scace tests last Sunday I forgot to turn preinfusion back on. I guess I'll better try to shots back to back later with and w/o PI and see if I am imagining things!

Chas.....firstly, thanks for running the numbers on your machine. Personally, my gut says that adding the PI feature to my S1 won't make any difference. I upgraded my heat sensor last year and while I was looking for quicker recovery and more accurate temperatures, I really haven't noticed anything different.

My situation remains the same. BTW, I leave the machine on 24/7. So my first extraction in the AM is without any flush, and I get an awesome Malabar Gold shot, which then becomes my morning cappuccino with our breakfast. My wife prepares "tropeiro style" Brasilian coffee, which I sometimes also drink. (Tropeiro is like Turkish brewing). Anyway, the followup extractions, which do benefit from both my flushing and jiggling the PF to clean up, and a reasonable recovery period..............well, they're still runnier than the first shot in the series?

In simple terms, based on what I've described, is my first shot hotter or cooler than the followups? I'd think it's hotter, as all the hardware is sitting there at max temp. After running an extraction, I'd think the brewing boiler would be "supposedly" coming back to my set temperature. Maybe I need, for Malabar, to run it higher. Dr. John recommends 205 F brewing temp for best results. I just don't like to go that hot, and usually set the machine at 202-203 F.

What do you think?

[JohnB]

Uh oh! The last couple of days my shots have been noticeably tastier and I have been roasting the same batch of beans for the last few weeks. Then I realized that after doing the Scace tests last Sunday I forgot to turn preinfusion back on. I guess I'll better try two shots back to back later with and w/o PI and see if I am imagining things!

You aren't! I've found that p/i benefits higher doses(17-18g) & takes away from smaller ones (13-14g) flavor wise. Haven't done much middle ground dosing lately so I can't say what happens there. If I could only have the fixed p/i I'd pass but I do like the programmable version.

[JohnB]

My situation remains the same. BTW, I leave the machine on 24/7. So my first extraction in the AM is without any flush, and I get an awesome Malabar Gold shot, which then becomes my morning cappuccino with our breakfast. My wife prepares "tropeiro style" Brasilian coffee, which I sometimes also drink. (Tropeiro is like Turkish brewing). Anyway, the followup extractions, which do benefit from both my flushing and jiggling the PF to clean up, and a reasonable recovery period..............well, they're still runnier than the first shot in the series?

In simple terms, based on what I've described, is my first shot hotter or cooler than the followups? I'd think it's hotter, as all the hardware is sitting there at max temp. After running an extraction, I'd think the brewing boiler would be "supposedly" coming back to my set temperature. Maybe I need, for Malabar, to run it higher. Dr. John recommends 205 F brewing temp for best results. I just don't like to go that hot, and usually set the machine at 202-203 F.

What do you think?

So have you tried starting with a couple flushes & dialing in the grind/temp yet? If the machine has been sitting your first shot will be cooler even if the boiler temp was accurate because the g/h is much cooler then it should be. If you want an accurate temp at the puck you need to warm up the g/h, otherwise you have no idea what temp you are getting at the puck.

[alsterling]

JohnB...... well, I did try running flushes first, and the output was as expected, runnier than usual. So my question remains; is the flush warming or cooling? I think that the machine actually is hotter if left alone. From all of this, what I'm learning is that if I want consistency, I will need to make every shot from the baseline of the machine having been flushed at least once to "normalize" the temp. I can then set my machine brewing temperature and grind until I get back to the extraction I want. Make sense?

[JohnB]

JohnB...... well, I did try running flushes first, and the output was as expected, runnier than usual. So my question remains; is the flush warming or cooling? I think that the machine actually is hotter if left alone. From all of this, what I'm learning is that if I want consistency, I will need to make every shot from the baseline of the machine having been flushed at least once to "normalize" the temp. I can then set my machine brewing temperature and grind until I get back to the extraction I want. Make sense?

When you run the flushes you are getting or are very close to the temp you programmed "at the puck", which is what counts. Without the flushes your shot will be cooler as the tests that Chas ran clearly show. If your pours are runnier after doing the flushes then tighten up the grind until you get a nice pour. If it tastes good leave it be or try it 1C higher/lower(at a time) until you get the taste you like best. Once dialed in with the flushes your shots will be consistant & only minor grind adjustment will be required from day to day due to aging/humidity/phases of the moon.

[alsterling]

John..... what I'm learning is that all variables other than my S1 temp settings and non-flush status, are set to yield a great shot. But the fact that putting the machine into a series of brewing cycles, changes the effective temp setting at the puck. I actually have both a IR reflective temp meter and a bi-metal "fluke type" meter from Harbor Freight. I tried jamming the temp sensor into the PF, but my readings were erradic. I've read the posts on making an effective temp sensing PF, but haven't felt it needed, mainly because my drinks usually come out just fine. However, I prefer being quantitative, and feel uncomfortable just saying that "it works.......", knowing that I don't really why "it works." Tomorrow AM, I'm going to raise the temp to 205F, do a couple flushes and readjust the grind to get back to where I normally hit on my first "untouched" extraction. I still want to do that video.

[BrewHaHa]

It doesn't seem like you want to raise the temp OR adjust the grind to make all your shots like the first shot.

If I understand you correctly:

1. Your first shot, that you pull before any warming flushes, is great.
2. Without changing any other variable, subsequent shots are not as good.

I think we've established that your first shot is almost certainly pulled at a lower temp, effectively, than the subsequent shots, since the group head has cooled down. Since the only difference between your awesome first shot and subsequent runny shots is temperature, all you should have to do is LOWER the machine's temperature setting, and make sure you always do warming flushes whenever the machine has been sitting idle. That way all shots will be pulled at the lower temp, instead of just the first shot.

At least that's how it seems to me.

-John

[TruthBrew]

I agree with BrewHaHa, it sounds like you have your machine set too hot (overall) for your liking.

Double boiler machines need warming flushes, not cooling (opposite of HX machines). So if you don't flush on the first one and the shot is good, it's probably cooler than subsequent ones.

[alsterling]

I agree with BrewHaHa, it sounds like you have your machine set too hot (overall) for your liking.

Double boiler machines need warming flushes, not cooling (opposite of HX machines). So if you don't flush on the first one and the shot is good, it's probably cooler than subsequent ones.

I'm tending to think you may be right. I pulled out my digital thermocouple. I put the bimetal tip in the PF, right under the shower curtain. I saw the temp gradually climb on progressive flush shots. I reset the machine to 205F, but am going to go down to 200F and see what happens to the extractions.

[JohnB]

I'm tending to think you may be right. I pulled out my digital thermocouple. I put the bimetal tip in the PF, right under the shower curtain. I saw the temp gradually climb on progressive flush shots. I reset the machine to 205F, but am going to go down to 200F and see what happens to the extractions.

If you reset the machine to 205C how high was it set before that? Have you had this same issue ever since you bought the machine?