Brewing Coffee

[andyd273]

So I'm listening to QS for the fifth or sixth time now, and something I've noticed before, is that several times it mentions him brewing coffee using cold water.

The first time is right after cleaning the pots the first time, Ish sees that the pots have both hot and cold water pipes, and he notices that they are set to deliver lukewarm water. After cleaning the pots, he closes the hot water, cranks open the cold valve, and prepares to brew.

Later on, he mentions brewing coffee again, and says something like "as long as we have coffee and plenty of cold water".

It just confuses me because I personally like my coffee hot.
I did a little research, and while there is a cold brew method, it takes a long time and by all account is pretty dull/bad.

I must be missing something fundamental, but every time I hear it, it throws me off a bit.
Maybe it's a percolator style?

[Tara_Li]

I'll leave the details to the coffee-nistas here, but all of the large quantity coffee brewing systems I've seen in the military/semi-military operations use something akin to percolation (though I'm not certain of the details).

[andyd273]

This makes sense.
I haven't spent much time around percolators, so I didn't really think about it until I was half way through my post.
Probably more efficient than a 40 liter drip machine.

[nlowell]

The generally accepted protocols for cold water stem from the old percolators where the difference in temperature from top to bottom provide the suction to move water up the hollow core and onto the top of the basket.

Subsequent use of cold water as *source* is the result of the nature of hot water systems that bring water in, heat it and re-heat it, driving all the oxygenation out of it ... in effect ... making it "stale" tasting.  Using cold water (water that has not been heated and allowed to stand at temperature) assures that when the water is heated up in the pot, the freshest possible coffee gets brewed.

He's not dripping cold water through the grounds. He's using cold (fresh) water to charge the system, heating just once, and then dripping it through the grounds at temp.

Sorry for the confusion there.

[Tara_Li]

See, this is why I let the Coffee Geeks answer more fully.