The mechanics of brewing cold brew coffee are simple but in practice the activity is often messy, frustrating, and time consuming. There are products for sale to help make the process go more smoothly though. The $40 (roughly £30 in the UK and AU$55 in Australia) Toddy Cold Brew System is one such gadget which certainly succeeds at its task and for not a lot of money.
As kitchen contraptions go, the Toddy is very bare bones. The kit consists of a plastic brewing container, essentially a bucket, attached to a handle. At the bottom of the container is a small, recessed hole and reusable felt filter pad that you place above it. Sadly the Toddy can't use paper filters. Plugging the hole is a tiny rubber stopper. The lidless container then rests on top of a squat glass decanter.
To brew, just add 12 ounces (340.2 g) of coarse coffee grounds to the container. You then combine that with 56 ounces (1.7 L) of cool water. Of course, you can't throw everything together all at once. Instead the manual asks that you stagger ingredients, half your grounds then half your water, and repeat in order to ensure an even mixture. It takes a little practice to get the process right.