The Small Chemex Is Different: The Ultimate Guide To The 3-cup Chemex
Pretty much every Chemex tutorial/recipe out there is aimed at the "big guys". 6 and 8 cup Chemexes with larger batches of coffee. But if you - like me - are the proud owner of the small 3 cup Chemex (the odd-one-out Chemex), you are out of luck. Usually, there is little from the bigger recipes you can apply with the small one.
After many experiments, several really bad brews and some really tasty ones, I decided to compile the ultimate guide to the 3 cup Chemex.
1. Filters
You can't use the bigger filters. You need to buy special small (half-moon) filters that don't come prefolded. Little origami before every coffee never hurt nobody.
2. Rinsing
While Chemex filters taste very papery in general, the papery taste is a bigger issue with the small guy. Since you are usually making less coffee, the paper taste can be more noticable. Rinse them really thoroughly. Cold and hot water. Drench them.
3. Grind size
Usually, people suggest a fairly coarse grind for a Chemex. This is true for the larger guys, because the combination of a thick filter and a larger coffee bed does really require a coarser grind.
But with the 3-cup, you need to go finer. Substantially. This will depend on how much coffee you are making, but I tend to stick with a grind similar to that which I use for a V60, maybe a notch coarser for larger batches (300-500ml). You should feel the individual particles, but not much more.
4. Dosing
This is mostly a matter of personal preference. I tend to follow the 60g/l (of brewing water) ratio, but I know folks who find that too "weak". It also depends on the coffee. Start with the 60g/l ratio and add a gram or two if you feel like it.
5. Capacity
The filter (unlike with the larger Chemexes) does stick out quite a lot inside the bottom part, which limits the capacity of the 3-cup fairly significantly.
With the filter in, the Chemex will comfortably hold around 400ml of brewed coffee (with you pouring up to 450ml). It's possible to make a slightly larger brew (500ml of brewing water) if you lift the filter at the end of the brewing process (so that the tip of the filter doesn't get submerged).
6. Water temperature
Again mostly a matter of personal preference and the coffee you are using. For light roasts and bright coffees, go higher (95-97C), for sweeter/chocolatier or darker coffees, go lower (90 and less even). I find 95C to be a great universal starting point which rarely screws up things.
Also, don't sweat temperature. If you don't have a thermometer or couldn't be bothered, bring water to boil, leave to cool for a minute and brew!
7. Bloom and stir
Let the first pour be roughly twice the amount of coffee used (I usually end up pouring between 40-50g of water). Soak all the coffee and stir the slurry with a chopstick or something else that is sufficiently narrow. You want to do this to saturate all the grounds evenly and completely. Wait for 30s.
8. Pouring
This has been my greatest struggle with the small Chemex. With V60s and larger Chemexes, you want to pour in circles, going to the edges and what not (see my Edges. post), but with the 3-cup, it never turns out well when you do that.
Stick to the center. Pour steadily and slowly into the middle of the Chemex. Don't circle, don't wiggle, keep it cool and straight.
If you are making a larger batch, you'll probably need to split the pour into two or three. That's perfectly fine. After the bloom, I usually pour up to half of the total brewing water and then gradually pour more.
Warning: the filter sticks out above the glass. I wouldn't push the surface higher than the glass.
9. Time
The brewing time will vary a little depending on the amount of coffee, but go for something between 3-5 minutes (again, larger brews will take longer). But you can taste if it took too long or not long enough; I don't usually keep time while brewing, scales are enough. Taste and adjust the grind size or pouring speed accordingly.
10. Conclusion
That's it! The 3-cup is a little more finicky than its bigger brothers, but it's also, in some sense, "easier", especially if you are new to brewing. You don't really need a fancy kettle, since you are just pouring straight down, no circles. Also, since you are not grinding as course, you can get away with a cheaper grinder, because at this grind size, even the cheaper ones tend to be fairly consistent.
