@silverwizard @Kevin Davy I get a specific brand of beans from Costco (don't remember the name but recognise the bag when I see it) and fresh grind them. I'm fortunate in that our tap water seems pretty good just on its own for hardness and so forth. The rest is just about the consistency of the measurements. (It was actually at your suggestion a while ago I started using a kitchen scale.)

I don't know that it's the best coffee in the world but given that pre-made cold brew is generally expensive and rather hit-and-miss for me, and this produces what I deem to be a consistently good cup of coffee at a fraction of the price, I've deemed it Good Enough for Me™.

@silverwizard Also, the recipe I adapted mine from said that a pitcher would keep in the fridge for up to two weeks. At first, I had no reason to doubt this because it never lasted me that long anyway.

I've since had to moderate my caffeine intake, and have learned to make less at a time because the quality seems to degrade a bit after about a week.