Unsolved Mystery - Gaggia Classic & Porlex manual grinder
Your expert opinions would be greatly appreciated. Here's the issue.
I recently bought the Gaggia Classic along with a Porlex grinder from a fantastic supplier in Melbourne. The end result was always no flow, regardless of grind adjustment, freshness of coffee beans, tamping, unless a very coarse grind was produced, which in turn made it almost impossible to turn the handle and/or get any decent extraction. I took it to the shop to get it looked at, and crikey, the same thing beset us, despite our numerous futile attempts to adjust the grind.
We decided to put it to the test with their grinder: immediate results, even if the first few settings were out just a bit, until we found the best setting.
I have replicated every detail - particularly the fineness of the grind - according to what was demonstrated to me, with my own attempt under their supervision. Once home I tried to make myself a coffee. The result - nothing. Just as before.
Logically there is something going on with the grinder. Has anyone experienced (or heard of) this frustrating and perplexing occurrence?
Many thanks in advance.
Quote :- The end result was always no flow, regardless of grind adjustment, freshness of coffee beans, tamping, unless a very coarse grind was produced, which in turn made it almost impossible to turn the handle and/or get any decent extraction.
This may indicate that you are over-dosing the basket. If I fill a standard Gaggia double basket to just above the top edge, settle the grinds, then level and tamp, I am getting over 21 grams in there. With an espresso grind and a firm to hard tamp this will choke my Classic almost every time.
I no longer use the original baskets, but when I did I would measure the beans going into the grinder, usually about 16 grams, and this would pull a good shot. If I remember correctly, this much would leave only a very faint impression of the coin when I did the "five cent test".
If your grinder is giving a good average size particle, but there are some finer ones in the mix, this could contribute to the problem. I'm not familiar with the Porlex, but it seems that most owners like them, so this may not be a factor.
Thanks for your reply. The very coarse grind that initially led to the handle being impossible to turn was pointed out at the shop so a much finer grind with the shop's own grinder worked excellently.
On the other hand I've followed your advice but the outcome is still the same. I would like to look more into the possibility of finer particles in the mix.
Yes, I did wonder about the fact that it worked OK at the shop, but I also wondered if the folk at the shop were using a different dosing/tamping technique resulting in a smaller dose and a lower surface level of the coffee in the basket.
Originally Posted by GiovanniG
All the symptoms, especially the hard to turn handle did point to choking caused by over-dosing.
So just to be sure that this is not the case, and eliminate it as a suspect :-
Did you try the "five cent test" ? and if so, what result did you get ?.
How far is the surface of the coffee below the rim of the basket after you have tamped it ??.
I'm no expert in particles sizes . In fact my only information in that area comes from an interesting article I once read about particle sizes and distribution, and I can't remember now where I found it.
One of the points it made was that uniform particle size was very important. Even when a fairly high percentage of the particles are the "correct" size, if there are enough finer ones, they will tend to "fill the gaps" between the good sized ones, and as the hot water expands the puck, this will create a barrier that the water can't penetrate.
To check this at home is you need another grinder for a few test shots. If that isn't possible maybe you could go back to the supplier with your Classic and your grinder and try them together in the shop. If the grinder is not compatible with the machine, perhaps they will exchange it for something else.
Thanks deegee. It looks like the grinder isn't compatible with the Gaggia after all. Your description seems to me the most fitting explanation so thank you.
I used my porlex mini for close to a year with a classic, never a problem, for the price it's a great little hand grinder. Made some good espresso that spurred me on further in my journey.
I always eliminated the variable of dose by weighing the beans used. Generally 18 to 20 g works in a stock gaggia double.
The grind adjustment on porlex can be fine tuned between steps and made to stay by using a 10mm nut on the end of adjustment nut.