In reply to Ramblin dave:
> Out of interest, how hard is it to dial in the grind for a Chemex? As I understand it, adjusting the grind is the only way to control the degree of extraction, but how hard is it to get right? Do you have to tweak it for different beans, or is it much of a muchness?
> I quite like the idea of getting one - they look pretty and seem to make lovely coffee - but I'm not sure I can be bothered repeatedly having to get the grind right when I go from pourover to moka pot and back or get a different packet of beans in...
> (Edit: sorry about the slight hijack...)
No worries! It really depends on the grinder and kettle. You need a consistent grind so that you get as less fines as possible for both more even extraction and less filter clogging. I can consistently get the brew time for Chemex between 3:30 and 4:00, no matter how much water I am using (usually go either 300ml or 750ml). It took me maybe 4 different settings until I got it perfectly right. I am using Orphan Espresso Lido 2 and it's way much easier due to grind consistency and stepless adjustment, but Hario Skerton is really difficult to dial in because of inconsistency and stepped adjustments. Of course, you would need a pour over/drip kettle (Hario, Bonavita, Kalita, etc.). I got Bonavita Variable Temperature Kettle, so I don't need to worry about the water temperature and got a goose neck for more controlled pouring.
Scales are inevitable to get consistent result. Some of them are with timers (Brewista, Hario), but they are quite gimmicky. I had/have both of them. Not really worth for the price, to be honest.
With larger volumes, you coarsen the grind and adjust the water level in the top bit of Chemex (aka where the slurry is). I usually pulse rather than pour continuously. For example, two different methods:
18g of coffee, 300g of water: bloom with 40g of water for 20s, pour water until scale shows 150g and keep the same water level. I finish pouring between 2:20 and 2:30. Dry grounds at 3:30.
45g of coffee, 750g of water: bloom with 150g of water for 20s, pour water until scale shows 350g and keep the same water level. I finish pouring around 2:30. Dry grounds at 3:30-4:00 (can't remember exactly and can't take a look at coffee logbook).
It might sound like a science experiment, but once you get everything right, there's no way back. The coffee is just delicious.