Oh, the lengths we’ve gone and the backflips we’ve done in pursuit of a cup of iced Coffea arabica: brimming mugs balanced in the freezer. Lava-hot joe poured over iceburgs. Whatever we did, it just didn’t taste like our favorite cafe’s version (sweet, complex and tea-like without the sugar), even when we used the same bean. Turns out, the flavor profile was too acidic from the initial hot brew. It all changed when, last summer, we learned how to cold-brew our coffee.
Even though there are many great guides on cold-brewing online, we were curious about how our friends at our favorite coffee shop on the planet, Bird Rock Coffee Roasters, brew their coffee.
Bird Rock Coffee, Roast magazine’s Microroaster of the Year for 2012, cold-brews using the Toddy method.
Bird Rock Coffee’s technique:
5 pounds light roast coffee beans (coarsely ground) per 14 quarts of filtered water steeped 16-24 hours at room temperature. Another 1/3 volume filtered water is usually added before serving over ice. Customers requesting a “cannonball” won’t get the extra water, and will experience a cold espresso-like refreshment on the rocks.
The Toddy method works very well on a larger scale — but isn’t ideal for our small at-home operation. Small Toddy cold-brew systems are also available for personal use, but former Bird Rock Coffee staffer Shane Voight recommended the following pitcher method instead, and we’ve been using it ever since. Not only does our iced coffee now taste sweeter and more balanced, the method requires no special equipment and is easy as peas (and more forgiving than your parents).
Proportions adapted for personal pitcher size:
– 1 part light roast coffee beans (coarsely ground; e.g. French press setting)
– 2 parts filtered water
– Fill a pitcher with one part coffee grind. We recommend about 12-16 oz. of grind for a 64 oz. pitcher.
– Pour two parts water directly over grind.
– Stir briefly to ensure full absorption.
– Cover and steep in the fridge for 20-36 hours (or 16-24 hours at room temperature).
– Strain concentrate through sieve or cheesecloth into a second pitcher. Strain again if necessary.
– Return pitcher to fridge. (It’ll keep for up to a week.)
– If you want to try Bird Rock’s “cannonball” style, serve concentrate chilled and on the rocks.
– Or, for a traditional iced coffee, pour concentrate and additional 1/3 volume of water over ice and serve.
We usually start steeping in the evening, so, after 20 hours in the fridge, it will be ready when we come home from the office the next day. Steeping in colder temperatures extends the required brewing time necessary to release a balanced flavor profile.
Still, the process and ratios are very forgiving. It’s okay to eye the volumes. Cold-steeping in the fridge means you could even go another 12 hours without over-extracting your grounds, which causes sourness. Extracting too soon, on the other hand, results in an acidic taste, because the acid content is what gets released into the brew first. Also, the freshness of the beans does not seem to be as crucial as it is in hot brewing. We have gotten away with using older grinds without too much impact on flavors.
Using a quality light roasted bean is very important to develop that tea-like, sweet, mild and balanced flavor profile. For cold brewing, stay away from the medium and dark roasts for the same reason char-grilled meats don’t taste so great served cold.
Plus! There’s an even better method for cold brewing that Bird Rock Coffee Roaster will soon deploy this summer. According to manager Jocylynn Breeland, a Kyoto cold drip rig (extremely brittle distilling tube and all) was shipped from Japan and has arrived at the store. Jocylynn and store owner Chuck Patton are “dialing in the rig and establishing the ratios” prior to introducing the method to the shop. Carefully sourced beans + quality low temperature roast + Kyoto cold drip = cold-brew perfection.
Even more exciting, Bird Rock also plans to start serving growlers of coffee in the near future for customers to take home.