Gaggia Classic and new Isomac Professionale
Well I finally upgraded to some decent equipment. Just a quandary I'm hoping any of you might be able to rescue me from.
Here's the problem:
Using a grind setting fine enough to get it to pour. But,
Uneven pour: appears great from one spout initially, delayed pour from the other. Then a faster pour from both.
Using an Italian made tamper in the $60-$70 mark.
Fresh coffee beans.
Much appreciate any advice!
What's your pour volume:time? Should be in the ballpark of (using a double basket) 60ml (assuming fresh beans, that can drop down to about 40 depending on age, as older beans produce less crema) in 25-35sec. Better yet, if you have a suitable scale, weigh it out to ~25-30g in the same amount of time.
In visual terms (with a naked portafilter, which would be a valuable tool IMO) this should result in thick globules in the first few seconds following the appearance of drops on the surface of the basket, followed by a stream like a mouse's tail, which (with fresh beans) will form a thicker cone over the course of the pour before thinning out (at which point, or before which, I would cut the shot). That point should present as a thinner, lighter, more watery stream from a double-spout portafilter.
Your uneven pour could be tilting of the machine or an uneven tamp. A naked PF would help you see what's going on, but taking particular care with the evenness of your distribution and tamping will help. After tamping, make sure the tamper is not tilted in the basket before removing it.
The tamper "quality" is irrelevant; the fit in the basket is most important, along with the ease with which you can apply an even, consistent tamp with it. a well-fitting $20 Al tamp off ebay will do much the same job as a similarly well-fitting hand-made, high-finish model.
Just to ask the question; what does the espresso taste like?
Thanks again for your reply. Despite the aberrations in extracting a decent shot I'm getting about 60ml in 25 sec with a nice brown crema, yet something still isn't right if I'm not seeing the attributes you describe. Initially a few drops emerge like a leaky tap, which proceeds to a gentle stream (usually from one spout), thicker globules culminating in a slightly faster extraction. The end product is actually quite nice, not bittery or weak, but evidently falls short if it deviates noticeably from what a proper shot should look like as per your description. I'm using 16gm coffee beans. Not sure if this is relevant but I've also noticed that the coffee bean holder of my Isomac grinder becomes loose during grinding.
Thanks for your help.
Hello Giovanni, I went through the uneven pour thing with my Classic at one time. I blamed it on the machine's design - the water is fed into the group head from the left side, and that was the side that started first and flowed faster when I used the double spout P/F.
But the result in the cup was pretty good, so I lived with it. Then one day I was just flushing water through the P/F and I noticed that both spouts started at the same time and flowed evenly. I tried it with another P/F and it was the same. So tested both of them again with an empty basket in place - still even. Then I tried them both with different baskets.
Every combination of P/F and empty baskets that I tried all started at the same time, and all flowed evenly. It was not until I put coffee in the basket that I got an uneven start and/or different flow from the two spouts.
After some more trial & error, I decided that it was because I was not distributing or tamping evenly. I found that I got the best start/flow when I got everything right.
Right grind, right dose, no clumping, even distribution, an even tamp, resulting in a level surface just below the shower screen.
My shots usually start slowly and then speed up a bit. I think that the increased flow later in the pour is fairly normal, and it may be partly an illusion, because the early flow is viscous and dark, but gets lighter and quite foamy toward the end, so it looks faster.
I can't offer any comment on the grinder because I don't know anything about Isomacs.
P.S. it may help to have a read through this thread :- http://coffeesnobs.com.au/general-co...-pls-help.html
Last edited by deegee; 27th November 2013 at 05:04 PM.
Not at all. The values I gave will usually get you in the ballpark of good coffee, but personally I prefer shots that would be far too tight/slow/short according to conventional wisdom. It's all about taste.
Originally Posted by GiovanniG
Once you've reached a point where you feel your tamping is consistent, then I would recommend spending some time playing with variables. Maybe try 18g in a double basket, adjust the grind to make the flow "acceptable" and then figure out whether you like it better or worse. Once you've found a dose you like, try a little coarser grind or a little finer and see how you like it best then.
Until your temperature-surfing technique is solid (I never bothered, opting to fit a PID instead) you will find variation in your shots (taste-wise) as the temperature can vary significantly.
At the end of the day, with the equipment you're using, if the shots taste good, that's a success.
When you say the coffee-bean holder comes loose, do you mean the hopper? Is the hopper used to adjust grind size on your grinder?
How much of a gap would you say is left around your tamper when it's in the basket? From experience, I'd recommend spending the fifteen bucks to get a precision (EP Precision, I think?) basket from Talk_Coffee. They really do improve things over the stock Gaggia baskets.
Thanks for your suggestions guys. It seems no matter what I do there is little that differentiates one shot to another. Grind adjustment, dose adjustment, etc. The result is a crema with a spongy looking texture on one side of the cup.
Dragunov: yes the hopper becomes a little loose while it's grinding, and it's used to adjust grind size, although this doesn't seem to affect the grind adjustment scale. The gap left around the tamper in the basket is approx. 4mm.
Thank you again.
Last edited by GiovanniG; 30th November 2013 at 04:12 PM.
4mm is too much (IMO).
Get a tamper that fits your basket correctly (0.5-1mm gap between tamper and basket, max) and you may find that your extraction improves. Or get the EP basket and then get a tamper to fit.
If the grind adjustment doesn't change then the loose hopper is nothing to worry about.
Thanks for your help and your expertise! But it seems a lost cause despite the experimentation. I've also noticed the temperature of the espresso is lukewarm.
Any further advice?
I suspect you're not leaving enough recovery time between shots, would I be right?
One of the first/biggest mistakes I made when trying to get my shots right was pulling a shot, tasting it, finding it sour, adjusting my tamp/grind/whatever and immediately pulling another shot.
The result was an increasingly sour result and an increasingly buzzed and shirty operator.
I'd advise leaving at least five minutes between shots on a stock machine or learning how to temp surf. The Classic is simply a thermally unstable machine under load, due to the tiny boiler and wide thermostat band, so as much of a pain as it is you'll have better results if you take that into account.