Fining is a super common technique in brewing/winemaking. I wonder how they chose that specific fining agent (other than that it's vegan, though there are plenty of other vegan options).

One thing that would make this technique better is decanting before adding the fining agent.

E.g.,

• combine coffee/water
• let sit 1 hour (or however long it takes for extraction to level off) -pour off supernatant -add fining agent
• wait till tomorrow
• decant again

Fining agents bind with stuff in the coffee, and by adding it at the start, you'll probably lose a bunch of it to larger coffee particles that would have fallen out of solution easily.

Finings work in 2 steps: coagulation and flocculation. First stuff bunches up into larger particles due to electrostatic charge (coagulation), and then it falls to the bottom (flocculation). The flocculation part works better the colder you get it.

The only thing I didn’t get: after making the ground precipitate to the bottom naturally, one could just filter it in a V60 without any issue. Normally I make cold brew with coarse ground coffee. Then I separate it in two steps, firstly pouring water in a caraffe leaving most of the grounds behind and then filtering the much cleaner liquid in the V60, which then takes much less time (but yeah more than filtering hot coffee) With his method the liquid poured is even cleaner even without additives, so I guess they’re not necessary at all

I was just about to post this here as well

I am definitely going to try this recipe. The concentrate that a Toddy recipe makes does not sit well with my stomach (yes this is after the 1:1 dilution). I guess I’d have to ditch the Toddy unless I try to brew within the constraints of it’s size.