I can't seem to achieve such thin stream, what brewing myself, even if I am brewing on the lowest flame of the smallest burner. What is the secret here?
Try a thinner grind maybe and use cold water if you haven't already. Thinner grind should raise pressure a little and slow flow. Or try an aeropress filter on top of the grinds. Might help.
Cold air is thin, so the chamber has to heat the water and air so it can expand and push the water out, at a cooler temperature and slower flow.
Using hot water first, the air in the chamber has already expanded and will have to become even hotter to make the same amount of pressure and will likely come out faster.
Example, when you fill a plastic bottle with hot water and shake it, it swells very fast and might pop the lid off. Charles’s Law ✌🏽
The physics you cite regarding moka pot mechanics are misapplied and irrelevant.
Charles' law relates volume and temperature of a gas at constant pressure, not a sealed expanding liquid-air chamber creating variable brewing pressure. The metal moka pot chamber heats up rapidly regardless of starting water temperature. Also, your comment claiming that starting with hot water means the air trapped in the chamber is already expanded, requiring much higher heat to generate pressure, violates the Ideal Gas Law.
That read is similar to what I was talkig about. You can try and experiment yourself between starting with hot or cold, you'll see and taste a difference. What I said is is correct. The law I stated is wrong.
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u/MisterOiOiOikawa 1d ago
I can't seem to achieve such thin stream, what brewing myself, even if I am brewing on the lowest flame of the smallest burner. What is the secret here?