I got turned on to cold brew a few years ago thanks to a post from Cory. Since then I have started using a V60 as my main brewing method but cold brew is still go to method for bringing good coffee with me when I bike to work.
That being said, last year I took a brewing coffee at home class at a local coffee shop. The barista there recommended a ratio of 8.25 cups water for 12 oz. This ratio was meant for use in a toddy and obviously won’t fit in your average french press but a little math can get you the right amount. This turned out much better for me than the toddy recommendation which I think is 7:12. Other things worth mentioning are brew time can be 4-24 hours with the same results (longer than 24 hours and the mixture starts to ferment) and make sure that if you have the option you are using coarsely ground beans since they will yield the best results.
Hopefully this helps a bit. I haven’t tried this with a french press, but general principles should transfer between that and the toddy
