Cold brewed coffee has been available for longer than I have been alive, yet I had not sampled it until last week. My local roaster was offering for sale the Toddy Cold Brew System for home use. When I asked him about the merits of the system he simply told me to try a cup at the downstairs cafe. I always follow his advice and did this time as well. I had the coffee cold and asked for no ice. I received about ten ounces of the most delightful cold coffee I have ever enjoyed. It was fruity, soft and very different than any I have had before. Makes sense, as cold brewing lowers acidity and caffeine. I was excited to try making it at home.
I visited the roaster again this week, brought the system home and fired it up. Only without the fire. The only heat was generated from my burr grinder, which was designed to grind a half ounce at a time for espresso. I gave it a rest after each of twelve ounces was ground (the maker suggested twelve ounces of coffee, but said a full pound could be carefully brewed). The grinding process was a pain and I worried I was shortening the life of the grinder.
Next time I will have the roaster grind it for me (something I would never do if I meant to brew the coffee over a period of days, but here the whole quantity gets used at once so it seems to be the best approach).
I started the brewing process at 11:00 am. In my haste, I didn’t consider the twelve hour suggested brewing time. As it was, I should have let it brew until 11:00 pm, but I am happiest to start sleep at 10:00 or even 9:00 when allowed. Considered setting the alarm for 11:00 pm, but then I would have wanted to babysit the thing for at least half an hour to make sure it drained and to put it in the fridge when it was done. I value sleep even more than coffee, so I pulled the plug after ten hours.
I was relived to see the concentrate draining from the brewing chamber at roughly the pace of espresso draining from an espresso maker. At that pace, it shouldn’t take long to drain the expected 36 ounces, but I had my doubts. Some users have reported draining problems. The system has a polyester filter at the bottom of the brewing chamber which can become clogged if the coffee is ground too finely or if the coffee grounds are disturbed during the wetting process. If the filter clogs, the user is advised to use a tool to reach through the grounds and scrape the top of the filter. I pictured the clog recurring repeatedly during the draining process and the whole process becoming generally not fun.
Happily the pace of draining was more or less constant and then stopped after thirty minutes. No fiddling with the filter. Having been through one brewing cycle, it is obvious that I should buy the coffee in the afternoon, start the brewing in the evening and drain the system upon waking.
I ended up with 32 ounces of concentrate, rather than the 36 ounces. Might not seem like much of a difference, but four ounces short means two fewer cups of coffee. Let me explain. Our coffee cups hold 6 ounces of coffee. The system maker suggests diluting the concentrate by a ratio of three to one (that is, three parts water to one part concentrate). When aiming for six ounces of finished coffee, I’d use 1.5 ounces of concentrate and 4.5 ounces of water.
That said, I preferred the coffee resulting from two parts water to one part concentrate. Some users even reported preferring a one to one ratio. I wonder if some new tasters, myself included, wanted stronger concentrations to try to bring back some of the acidity to which they are accustomed. Time will tell. My current preference for a stronger concentration might change when I brew for the entire twelve hours. It also occurs to me that the ambient temperature probably makes a difference with cold brewing. While hot brewing generally occurs in an 180 degree environment, the temperature of the mix during cold brewing is dependent on the ambient air temperature. In our home, that can vary considerably. Maybe cold brewing during the summer requires fewer than twelve hours and during the winter requires a longer cycle.
Lacey and I each had a hot cup this morning (mixed at two parts water to one part concentrate). We arrived at a hot cup by adding concentrate to the cup and then adding hot water. I have not done a blind taste test, but for now I will say the end result was not remarkably better than hot coffee brewed in our french press. I am guessing that adding hot water can change the flavor of the concentrate in some of the same ways that brewing with hot water would. You should still have lower acidity and caffeine, but for now I will guess cold brewed coffee might best be enjoyed cold.
Then there is the cost. Cold brewed coffee is the clear loser here. Cold brewed coffee mixed at three to one costs $0.50 a cup (beans cost $14.50/pound). Cold brewed coffee mixed at two to one costs $0.65 a cup. Hot coffee brewed in the french press costs only $0.36 a cup. Apples to oranges, but since I did the math, a double espresso costs $0.44 a cup. Interesting that they are all in the same neighborhood (and so very much lower than the prices paid when others do the work for you), but having done the math and tasted the results, I will not be selling my french press. I will probably use it for morning coffee and also have a pot of concentrate in the fridge in the summer for cold coffee drinks. I will never give up my afternoon espresso. To me, extraction in an espresso machine is by far the best way to enjoy well roasted beans.
I will not give up. I will continue to fiddle with the cold brew system. My roaster said they have enjoyed the results from finer ground beans. This may work in the commercial maker, but it will be interesting to see if draining issues arise when I use finer grinds. As always, it will be fun to experiment and to share.