strange salt in san pedro extraction?

[grg3135]

Hi all, I was talking to someone on the train the other day and he said that he had just tried his first san pedro extraction. He used 10 kilos of fresh san pedro, put it through a blender and cooked it with water and 20-25 oz of lemon juice for 7 or 8 hours (adding fresh water to the pot as necessary). When he was straining the pulp and transferring the remaining liquid to another pot, he noticed a salt at the bottom of the original pot. He assumed it was excess citric acid from the extensive amount of lemon juice but he tried it just in case, and it wasnt sour. It actually didnt taste much like anything, or so he said. He is assuming that it was not psychoactive either, as he did not feel any effects (although he only ingested a miniscule amount). What would this salt be?

One other unrelated question, when he was cutting the cacti, he said that he saw white circles in the flesh a few stalks of it. Not fuzzy like mold but almost as a knot looks in a tree. Is this normal? He ended up cutting these knots out and throwing them away, just to be safe. He wanted to be sure to mention that these knots were not visible from the outside of the cactus, only on the inside of the flesh.