I distinctly remember someone posting a different thread a while back along the same subject, AFAIK a ph of 11.5 is the highest you need to get all the alkaloids from MHRB. To freebase half of the DMT present in bark you need only a pH of 8.68. At pH 10 one can net over 90% of the DMT. This is according to the pKa of DMT. At pH 11.5 nearly all the DMT is freebased. If doing an A/B you can get decent yields with as little as 50 percent. With an STB you need 99% for decent results. Also, remember that pH approximates a logarithmic scale, so pH 13 is 10x more alkaline than 12. Swim thinks pH 12 works good for Swim.
Disclaimer: All words and images posted herein under the username Jumper are strictly for entertainment purposes only, and are fictitious in nature. Swim is the imaginary character of a schizophrenic and all posts connected to said entity are the deluded ramblings of a madman, who admits that all posted data herein was electromagnetically beamed into his brain from a HAARP antenna array.