I have some caapi tea that was cooked for 3 x 3 hour simmers with no acids. Could I still extract the alkaloids using gibran's caapi tek or will it not work because I didn't have an acid cook? Could I just give it an additional 30 min simmer with an added acid?

I'm sure that would work fine, although the acid may help get any extra goodies out. You could always do an extra boil or two on the leftover vine with some acid just to make sure and then add to your already existing tea.

Yeah it works without an acid. If you are using tap water and for some reason your tap water is specially basic, it might decrease yields, but since the plant is slightly acidic and alkaloids are naturally in salt form, it should work. In the amazon traditionally ayahuasca is boiled without any added acid.

In any case adding an acid can help increasing yields, so you can do normal 3x boils and then do another long overnight (or two) soak and finish with a bit of boiling to get most of the left over alkaloids out.

As others have said, you are fine without acid, but adding acid will help exhaust the vine more thoroughly.

A little experiment I did a while ago on precisely this topic. Hope it helps

thanks everyone, exactly what I needed to know!