How to change the Grinder Blades on your Jura, Coffee machine

I often wonder why I find it so hard to convince people they should change the blades on their Jura coffee machines, a new set of blades makes a huge difference to the flavour of the coffee and it’s not that difficult as I will now demonstrate.Most Jura grinder blades are blunt and corroded after only a few thousand cups. The official line from Jura is that their blades will last 10,000 cups but they certainly don’t. Most are blunt after about 3000. 
I can not overstate the difference sharp grinder blades make to coffee extraction. As soon as I fit a new set, the coffee not only tastes better, it smells better. I have been amazed at the difference a new set of grinder blades can make to a tired old automatic coffee machine. The difference is amazing, after changing the blades and doing nothing else the crema layer more than doubles and the flavour is back. When I perform a service on an older machine I always offer my customers the option of a new set of grinder blades.
 You will notice if your blades are blunt that you need to adjust the strength of your coffee to the strongest setting. This is because on most automatics, the setting to increase the coffee strength, just runs the grinder for longer. The longer the grinder runs, the more coffee powder that is produced. However, as the blades become blunter, the less the volume of coffee that is ground in an allocated time. So for example the medium setting may run the grinder for 3 seconds and produces 8g of coffee. But when the blades are blunt, that 3 seconds now only produces 4 g of coffee. So the pucks are small and the coffee weak with no crema. You probably will not see well formed bulky pucks in the grounds bin, just grounds with the consistency of wood chips or sloppy pucks.

So have I convinced you to change the blades?, purchase a new set of Jura grinder blades here…

Ok lets go,It will take you about an hour. It is a mucky business, so do it in the garage or on the kitchen bench when the wife is out. Anyway It will be worth any grief that may come your way.

The following pictorial briefly shows the steps to replacing your grinder blades in a Jura Coffee machine. You don’t need to remove the grinder from the machine. 

A Jura J5 Grinder, I’ve cleared out the beans with the Vacuum Cleaner.


Remove the Outer Black Adjustment Ring and mark the current position of the blades. This saves a lot of time calibrating the new blades.
Wind the outer ring anti clockwise and remove the top blade, you will be left with this view, clean out all the ground coffee.
Prise out the plastic insert and replace the outer blade. The top insert is held in place by 2 plastic tabs, The old blade will just pop out and the new one pop in.


jura-grinder-blade-change-16
This is a Delonghi Grinder
The new outer blade all fitted in the plastic housing ready to install.
Remove the central blade and the spindle by undoing the screw in the middle. Remove the old blade and clean up the spindle and inside the grinder. Remove the springs and ball bearings too. Use a magnet.
After cleaning up the internal cavity of the grinder refit the spindle.
Place the springs and the ball bearings back. because you magnatized the ball bearings and springs they stick nicely.
Carefully place the new central blade back and screw it down.

All that is left to do is reinstall the outer blades and calibrate the grind. This should not be too difficult as you have the marks as a starting point. A task easily achieved within an hour and probably an essential repair on a jura machine. The coffee is just so much better.

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