Hey fellow coffee friends. As it is hot season here in Germany I actually enjoy my coffee cold, so I set up a cold brew every two or three days.
Well, when I got into that habit I got the hint to never let the brew touch metal as it alters the taste to the worse, it gets sour and „off“.
Now my question is, is this a myth? I see cold brew makers which would be way more convenient than my measurement cup/cotton filter method, but all of them have some kind of metal filter, so I am very reluctant to buy one of those. Has anyone insights and our experience on this topic?
I make my cold brew in a plastic and glass contraption that produces a drip onto a reservoir into a bed of grounds that has a metal filter on the bottom. I can’t say I have ever noticed a metallic taste to the coffee. I put an aeropress filter on top of the grounds to help the moisture distribute. I suppose you could do the same at the bottom to avoid direct contact between the grounds and the metal in the filter, if it was a concern that some kind of reaction might take place (that wouldn’t otherwise take place in the presence of ~0C water + dissolvables).
I do a very primitive method - I stir coarse grinder beans into the water and let it rest in the fridge for roughly about 12hrs, then filter it with a coarse cotton filter and then with a permanent dripping filter.
The result is great, but the effort is high.
Maybe I just let it rest in the French press and compare the result.
I bought some large paper bags on Amazon that work like tea bags. It takes longer (I usually let it sit for 2-4 days) but the effort is extremely low. And you never need to use any metal :)
That’ll work. I will have to try that myself to see whether immersion vs percolation in cold brew makes a difference.