Post By Tjwhite
Moka pot - what would cause this?
Previously reliable (but no-name) moka pot; coffee suddenly starts coming up super-weak, almost clear, just hours after making its regular rich black oozing rocket fuel. Tried coarser and finer grind, replaced seals, no luck. Went out & bought a Bialetti which I'm sure will be reliable, but even it doesn't produce coffee as strong as my old one when it works. This has happened to me a number of times with pots suddenly making dishwater, then sometimes I try them again after months of disuse and they're fine. Any ideas?
I doubt it's the mokapots.
9 out of 10 of my mokapot problems are caused by putting too much coffee in the basket. I think when it gets wet it swells and blocks the flow of water. As the pressure builds the water tries to find another way through - either around the coffee, or pushes through a weak spot or something. Or else it can't get through at all. That's my theory anyway.
Try putting less coffee in. Flat to the top of the basket, not heaped out the top, not tamped.
(the other 1 out of 10 problems is a leaky seal.)
Last edited by Tjwhite; 2nd September 2016 at 08:28 PM.
Thanks for the suggestion. Didn't help in this case unfortunately, still came up weak and thin. Still, it got me thinking, since putting LESS coffee in, less compressed, is something that was counter-intuitive to me, I thought I'd try an experiment to test it under more ideal conditions. I made two pots with my new Bailetti, used pre-ground coffee just to make sure the grind was exactly the same, packed as much as I could into the first basket and squashed it down hard, loosely filled the second basket to the top.
Here's the first coming up:
Here's the second:
The first is definitely thicker, oozier, more like syrup and how I like it.
However this might just be because the new pot is unusually tolerant to being overpacked whereas maybe many others would fail and just let the water through a fissure in the coffee or elsewhere.
I've found my Bialetti works nicely with a light tamp, but it is easy to over tamp and cause all sorts of issues. I assume high back pressure from the tamped coffee forces the water around the edge of the basket. The coffee swells significantly more than in an espresso machine, so dose weight is important.
Maybe checking how the basket sits in the base, as some coffee oils or grunge may be creating a leak around the basket?
Random channelling maybe?
I guess more coffee in the basket means richer coffee out the top, but I find too much will make it unreliable. I guess the trick is to work out a technique for max coffee in basket while still being reliable. An even distribution will help. Maybe a different grind I don't know.
I'd love to know whether tamping helps. My thinking is that if you tamp a heaped basket you're basically doing the same as overfilling it (which would be fine if it worked reliably). And if you tamp a lesser amount down to below the top what happens? Does it stay tamped and affect the brew somehow, or does it swell and push against the filter in the same way it would if left untamped?
Moka pot - what would cause this?
Maybe try the following...
1. Weigh the coffee grounds you put in the basket (not sure what size your using... 2 cup / 4cup) I use a 2 cup and use about 14grams
2. When you change the grind size put in the same weight in so that your not putting in more or less coffee....
3. Repeat the process see if you notice any difference...
4. Sometimes it could be the coffee beans requiring different grind
Let us know how it goes
Not that I'd know but a moka pot has been my go to way of making coffee when i travel, which is about 4 months a year.
what I do, and I know a lot of ppl will tell me off for this, is I put less water in, start the water cold, and I do tamp, i leave about a mm or 2 between the coffee and the top of the basket. and I use an induction stove.
its all about the amount of water though, each pot ive used ive had to figure out, most of the time i only half fill them to get the rocket fuel im after...sorta like a ristretto
Imho tamping and leaving a gap might be a bit like not tamping and not leaving a gap. As in, the same quantity of coffee. So not sure about that. Just out of interest, when you brew it does it stay tamped or does it swell and fill the basket?
Putting less water in is a good idea. For some reason I hadn't thought of that. Will give it a go.
Well putting less water in worked a treat. I think over time my quantity of water had snuck up.
Thank you for your post...
you will find it swells, but the reason for tamping is so that the water doesnt find an easy escape and overextract one part of the grind while leaving other parts under brewed
glad it worked out