I love cold brewed coffee.
I was having issues with the acidity of regular hot brew coffee. I found a few places that sold low acid or even zero acid coffee but they varied from being expensive to being ridiculously exorbitantly expensive. Then I found cold brewed coffee at my local Starbucks. I liked the taste. I messed around with a few low cost home brew methods, like bags or soaking and trying to filter through paper filters. They all seemed to be messy and a lot of bother. Bags are difficult to wash out thoroughly. Since organic matter is trapped in the cloth and about impossible to wash out there is always the possibility of mold forming. This is not mentioned in most of the online cold brew sites. Some people refrigerate or freeze the filter material between uses. Or replace it often.
I bought an OXO cold brewer off Amazon; $50. It uses a very fine S/S screen mesh. That is the achilles heel. You do need very coarse grind coffee or it will not run through. I had problems with that. I found coffee grinders in stores vary, producing different results between different machines on the same grind setting. That was frustrating. By this time I was really hooked on cold brew. I did find that my Starbucks had a very usable coarse grind that was consistent enough. With Starbucks though, I had to buy their coffee and there are others I prefer; just as good and cheaper.
So I bit the bullet and took a chance on a baratza coffee grinder. Not cheap even on Amazon. $250 It works wonderfully and I use the coarsest setting. My only real complaint is that grinding produces static electricity and coffee particles end up sticking to the plastic receptacle making a mess all over. My solution to that has been to grind in the workshop. I do a couple pounds at a time and clean up with the shop vac.
I make about 32 ounces of concentrate at a time and store it in the fridge. I use a second quart container to store the diluted ready to drink coffee. Works for me.
When we go camping I take a bottle or two of concentrate along.