I got a kickstarter Bruer. Not the cheapest thing to make cold brew with, but significantly cheaper than some of the Hario and other alternatives.
60g filter grind coffee
400g cold water
50g cold water for soaking the coffee bed before starting the drip.
1 drip of water per 2 seconds and leave for 6-7 hours.
Or... visit www.funraniumlabs.com and order some Black Blood of the Earth. It's powerful stuff. *Also Phil was on one of the Lego with Friends and is a great and fascinating guy*
This is a bit late, but I like the Hario cold brew coffee carafe. I course grind with a burr grinder, and fill it's filter cup right to the top of the exposed mesh, and fill it through the grounds. I use a chopstick to make sure the coffee grounds haven't clumped up, and let it sit for minimum 12 hours, maximum 24. I remove the filter, try and drain any liquid in the filter without squeezing, and then top off the carafe with more filtered water. I use about a 60/40 mix of that and almond milk (60% coffee) over ice. It's probably sacrilege, but I tend to add some chocolate syrup. It gives me a much better tasting version of the iced mocha I get at dunkin, with none of the heartburn from acidity.
This does require some unique tools but it's the method I use to make cold brew:
Typically, you add 9 cup of water on 1 pound of coffee. That is cold brew concentrate. That is depends on how you are going to presented to your customer.
I then add 3 cups of water per one cup of concentrate.
You really don't need a brewer but you can buy Toddy cold brew system on ebay.
I just use cheese cloth to wrap my coffee ground and brew over night.
That is the way I do it.
If you want to be sophisticated system, here are some cool stuff.
Try a 50/50 mix of cold drip with indian tonic water over ice... its delicious.