So what's the story with this whole cold brew thing that's taking the world by storm? Give us a minute and we'll do our best to explain.
Cold brew is an alternative to a traditional iced coffee. Rather than pouring hot coffee over ice and melting all the ice, therefore diluting your coffee, you can brew your coffee with a cold water extraction for a smooth, balanced and hopefully delicious beverage.
How we make Cold Brew at Rosso is going to honestly be a bit different than you'll do it at home. We use 5 pounds of coffee - currently Don Joel Black Honey - ground at the coursest setting on a Mahlkonig EK43. We then put the coffee grinds into a reuseable filter in one of our commerical Toddy's. The 5 pounds of coffee grinds will then see 14 liters of water and they'll be left to brew for approximately 16 hours. When we decant this, it will have made about 10 liters of concentrated cold brew. What we then do is dilute this concentrate with equal parts of filtered water. This gets mixed into a keg, charged with nitrogen and tapped. The idea with the nitrogen is to give a creamy, textured mouth feel that drinks smooth, almost like a Guinness. We offer this in a refillable growler or in 16 ounce cups. This is obviously tough to do at home, so we've got a home version for you :)
Growlers available for purchase and fill
How we recommend doing Cold Brew at home is going to depend on your home coffee setup. For a general and easy method, we recommend using the Rosso coffee jar as it brews a nice size and if you're drinking Rosso Coffee, you'll likely have one. *we have a refill program available with these jars. Ask your barista next time you're in. With the jar, we recommend 75 grams of coffee ground at a coarse setting. First, you'll add that to the jar, then top with 600 mL of cold, filtered water - should fill to the shoulder. Put the lid on and shake two times. Then leave in the fridge for 14-16 hours. When your time is done, you'll have to drain the liquid from the grinds. We use a pre-soaked coffee filter in a pour over. The result should be 460~ mL of cold brew! This is not concentrate, so you wont have to water this down; however, if you find it's a little too strong, dilute and adjust these parameters to best suit your taste!! We've used Aricha and Pulcal in this method - both have been dynamite!
Rosso Coffee Jar or Cold Brew Device - you choose
If cold brew isn't your thing and you don't want to wait 14 hours to consume your coffee, we'd recommend brewing a filter coffee on top of ice. Make sure you factor in the amount of ice to your overall recipe so you aren't making an incredibly weak and watered down beverage! When this is the method we're using, we take our regular recipe - lets say 20 grams of coffee and 350 mL of water - and we use half the amount of water hot, and the other half frozen. So 20 grams of coffee brewed with 175 mL of hot water, on top of 175 grams of ice!
The reason most people seem to love cold brew is the lack of acidity that's present in the brewed coffee. Since the water being used is not hot, you are unable to extract the majority of the acidic compounds locked within the coffee. Generally, these acidic compounds are some of the first flavor characteristics you'll find at the beginning of a brewed coffee. For an experiment, and to better understand this, you could try brewing a coffee and separating different intervals of the brew. The first should be high body, high acid and not very balanced. The second, should have sweetness now present, with acidity and body lowered. The third should have the least body, the most dilution and is truly present to balance out the first component, leaving you with flavors resonating like the second portion.