House's Trichocereus Tea
A simple and effective Trichocereus Tea that covers basically everything you need to know.
Slice the cactus like bread into finger width portions.
Cut out the center white part and discard. Cut each rib of the star into a section and put these little pieces of chopped cacti in a plastic bag.
Freeze and thaw this bag 3x. This process will lyse the cells making the migration of alkaloids into the solution easier.
Use a large pot, preferably a big 5 gallon one, for every 4 feet of cactus. The more water you use during the simmer/boiling stage is what determines how many alkaloids will fit in the water. If you use too much water, however, you will be brewing forever. You do not meed to use any acids during this process, it only serves to make the brew taste even more nasty than it already is. Add fresh warm water to the pot when needed. It is also not necessary to mash the cactus.
You are going to need to filter the chunks out of the solution before you reduce all the way down. So decide when it is time to do this. During the last few hours of the brew, in which I usually shoot for ~8, I focus on reduction and do not add any water. Make sure you have another vessel that will contain the amount of solution you determined is appropriate for filtration. About a liter is good if my memory serves me right or more if you want. Any thicker and filtration will be more difficult.
Reduce the brew down. 30-100ml per dose is a good range to shoot for. A dose can be anywhere from 6", 12", 24", even higher. I would suggest starting with 12 and working your way up. Cactus potency varies from strain to growing conditions.
Drink. If I am ingesting a big dose I drink it over the course of an hour. If it's small I will just down it. I suggest having a lime handy to bite on after sipping on the soapy goodness that is the Trichocereus Tea. The mescaline comes on in ~3 hours. Some cacti have other alkaloids that kick in sooner. A good dose keeps me coming up and up for around ~6 hours. Enjoy.