Question for cold brew coffee fans about your system
Recently I began cold brewing coffee on a more regular basis to bring in with me to work. I don't have a Toddy or similar system, so I made do with what I have - basically I brew in a big pot using a fairly standard drip grind and then use my Aeropress to strain the concentrate from the grinds. which seems to work fairly well.
What I'm wondering, though, is this: what's your yield using a Toddy or a similar system and is it significantly different from mine?
I've found that when I brew 12 ounces of coffee in 7 cups of water, I only get about 4 cups of concentrate back. I might be losing a little to spillage and evaporation, but I'm assuming that the bulk of that loss is from the grinds soaking up extra water. I'm wondering if the toddy (or some other system) does any better or worse, or maybe if the grind makes any difference to the end yield.
I use my Toddy only for making iced coffee, as I prefer a French press for hot coffee. I've never done exact measurements with the Toddy. I judge by eye when I've added enough water, but it's obvious from the amount of water that drips through that quite a lot is retained in the grounds. One website I found says that nine cups of water (for a pound of ground beans) yields six cups of concentrate. This website recommends using a coarse grind, but I've seen others that recommend a drip grind. I would think that more water is retained in the grounds with a fine grind than with a coarse one, but have not tested this personally.
Grind definitely makes a difference. I like light-roast coffee, but strongly made. So I always use espresso grind, whether I'm doing cold brew or making hot coffee with a filter cone. For cold-brew, I just dump the ground coffee into a large glass jar, add cold water, stir, and stick it in the fridge for at least a day, taking it out and shaking it a couple of times. Then I dump it through a fine-mesh strainer. From there, I re-filter it through a filter paper. I've rinsed the filter with water first. Once I've pressed these grounds with a spoon, I dump them out and put the grounds from the strainer into the filter and press that, too. I never measured how much waste and yield there is, but am happy with the result and have not invested a penny in additional equipment.
I've never understood the benefit of making the concentrate. Maybe so you can make it for a few days ahead of time? I like my coffee a bit stronger than most and this method gives me decent strength and a lot of delicious coffee.
I make my cold brew using a 1:5 ratio of coffee:water. Right now I'm using an old protein scoop, so one filled with coffee followed by 5 of water. I like using a ratio rather than measurements because I don't always have measuring equipment with me and I can take this camping pretty easily as well.
It goes into a large enough container overnight, although I prefer around 12 hours.
When ready it gets filtered through a coffee sock I picked up when I was in Laos.
Finally put into a chilled glass with ice and sometimes a straw. So delicious.
I use a ratio similar to 1:5 but it's by weight not by volume, so if I'm understanding you right, your end product is less concentrated than mine.
As to why you'd want to make it more concentrated...
Convenience is a big factor, and probably the biggest factor for me. I only drink cold brew while I'm at work and prefer to use an aeropress at home. So a more concentrated brew lets me make more at a time and store it more easily. I'd have to have a MUCH bigger container to cold brew a pound of coffee to normal drinking strength.
More hypothetically, you're also changing the flavor depending on how concentrated your initial brew is. Some of the smoothness and mellowness that people often associate with cold-brewing is a direct result of underextracting the beans. The lower the ratio of water to coffee grounds, the lower your extraction percentage is going to be. Whether or not this is a good thing depends on preference. My coworkers really seem to enjoy the low-acid, low-bitterness flavor of (underextracted) cold brewed coffee. And it certainly sits easier in the stomach when working night shifts where multiple cups are needed. But many of my personal favorite coffees (African light roasts, for example) are wasted on cold brewing to concentrate precisely because the process doesn't highlight what's distinctive about those beans or bring out their complexity.
All that said, I've never tried cold brewing at a higher ratio of water to coffee, mainly because I have other methods I'm quite happy with when I'm aiming for higher extraction.