Ideas from the creators and testers:
The Bong Isolator is designed to keep your group head from overheating.
An overly hot group head could make your coffee extraction bitter.
The reason is that hot water passing through the coffee grounds extracts all kinds of flavours.
Some flavours, like bitterness, usually only are released from the coffee grinds with hotter water.
Therefore, many people find a more pleasant extraction comes from slightly cooler water than what many Generation 2 group heads provide.
However, there are a few trade-offs to using a cooler brew temperature.
If the water is too cold, then the extraction of pleasant flavours from the coffee may not happen.
This then leaves the taste kind of simple, with no complexity.
Another trade-off is that the way the La Pavoni works, colder brew temperatures end up feeling spongy on the pull and could have a lower shot volume.
The Bong Isolator helps you keep your group head cooler to help avoid bitter extractions.
It is especially helpful for the second and third shots where a group head without the Bong Isolator gets extremely hot.
Because the Bong Isolator keeps the group head cooler than it normally would be, it is important for you to adapt your extraction routine with this in mind.
We really recommend that a temperature probe or temperature strip would be helpful in understanding what is happening with your GH.
Ideas written above are not certain rules and each user will have a personal experience with the Isolator, which may be different from others, simply because the machines are also different.
Users had spongy pucks or low volume way before we created the Isolator.
Some did not.
A few ideas from Bong (creator of the Isolator) to avoid/solve such problems:
Low Volume or Spongy pulls solutions:
1. Purge/bleed false pressure;
2. Cold flushing;
3. Longer pre-infusion / saturate till drip / longer for fine grind;
4. Flushing 2 x include in your routine / to flush air;
5. Active pre-infusion (2 bar);
6. Fellini;
7. Bleed steam to reactivate pressure stat and pull at the high end of the dead bend (0.5);
8. Double pull;
9. Use deeper baskets (Elektra);
10. Set pressure stat at higher settings because now with the isolator you can, and still have a colder GH;
Until now, this has been one of the best solutions for our users.
With higher pressure, you will have more pressure and steam and a higher boiler water temperature.
11. Double shots: 2 x 12 x 24 = 48 ml.
The measurements show:
Chart 1 static heating temps difference between two types: NO ISOLATOR (RED COLOUR) and WITH ISOLATOR BLUE COLOUR;
Conclusions:
Standard NO ISOLATOR stable temp 104°C
WITH THE ISOLATOR stable temp 60°C
Chart 2 temps variations during and after pull:
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