Tastes good to me. It is like regular coffee, just lower acidity, which is what I need. I want it to taste the same as regular coffee! ;) To be fair, it usually tastes milder than how brewed coffee, and this is one of the things people like about cold brew.

Cold brew is much less acidic, and I find warmed cold brew to be exceptionally smooth compared with hot brew. I got my recipe from a NYT interview with the CEO (I think?) of Blue Bottle, though I've since lost the link. This is my copy:

https://rpdillon.net/recipes/new-orleans-cold-brew-coffee.ht...

Yes. The major reason for cold brewing coffee (or tea!) over simply cooling and icing hot brew is that you extract a different mix of compounds from the bean (or leaf) due to different chemicals having different levels of solubility at different temperatures.

Serving temperature affects flavor, too, of course. Darn near everything does.

See, for example: https://www.mdpi.com/2304-8158/9/7/902

This is only partly true. Because low-temperature extraction is much less efficient, it requires a much longer immersion/exposure time than hot extraction at ambient or slightly higher pressure. One of the effects of this type of cold extraction is the oxidation of the coffee, which is much greater with this method, giving the coffee an oxidised taste which, although not bad in itself (nothing is set in stone about personal taste), is not to everyone's liking. For my taste, I prefer to make it hot (with a higher coffee/water ratio than usual) and cool it down by diluting it with water or ice.

Definitely. Though the oxidation seems different? I don't find cold brew to taste "stale" the way hot brewed coffee that's been stored overnight in the refrigerator does.

I have a bunch of kegging equipment that I don't use anymore because I've lost my taste for beer, and I keep wanting to see what happens if I use it to make cold brewed coffee under a bed of CO2.

Also, y'know, coffee on tap at home.

Won't the CO2 make the water acidic?

Nitrogen is better, but the equipment is more expensive and finicky. CO2 under just enough pressure to keep the oxygen out shouldn't dissolve into the liquid too much, though.

The downside is that you then couldn't use gas pressure to push the liquid through the tap line, but you can use gravity or a beer engine instead.

Good is subjective. I've trialed cold brew at home and have been serving it warmed. I prefer my coffee hot. I thought it tasted fine, different but neither better nor worse than hot brew (drip in my case.)

Since it's DIY I have no one to argue with about how to serve. I have stopped making cold brew for the most part because it seems to require more coffee beans than hot brew. Maybe I'm doing it wrong. I don't have a "cold brewer" and just add water to grounds in a glass jar with lid and shake when I walk by before filtering it the next day. Neither have I compared the cost of electricity for drip vs. the extra beans for cold so I don't really know which is more cost effective.

I think people like it because it has less acid.

AFAIK the aromatics in coffee are quite volatile so what you end up with is like "grain soup". The coffee tastes more like the roast than the actual coffee.