I am trying to understand the point of cooking the MHRB three times as outlined in the DMT handbook . Does not the initial cook get the goods out ? Instead of cooking the bark three times for 1/2 hour why not just cook it for 1 1/2 hrs if time is what is needed ?
Actually as far as any extraction tech goes , why not just increase the inital soak , instead of doing it several times ? Is the issue just volume of material or what ?

Could someone please enlighten me on this ? Thank you !

think about an elevator. The first people come in fast because there is space. At some point it starts getting crowded and people take longer to get in and adjust themselves. Even if you wait a long time, only few more people will come on. On the other hand, if you just let the elevator get reasonably full and then bring the next elevator, on the same amount of time one can get much more out.

3x cooking takes the most out of the plant. Just once is a waste.

Ok , to me it sounds like your saying the acid gets saturated and can no longer effectively remove the goods , hence the need to add fresh . I can understand that if that's what your saying . If that is the case why not just increase the volume of liquids to match the entire three ? Is this not plausible either ?

not exactly fully saturated, but the closest it is to saturation the slower it dissolves the alkaloids. And yes increasing the amount of water will for sure help getting more actives out, but still if you spend the same time and same amount of liquid, one doing straight, and the other doing 3x, the 3x will get more alkaloids out.. Maybe some chemist can explain you more if you want..

Endlessness , I understand what you are saying , thank you very much !

The remaining stuff that you want to absorb, but will not absorb in your original solution, will absorb more readily in a fresh solution. that's because when the original solution reaches a certain concentration it's less capable of removing the residue. A better analogy than endlessness' elevator anology is: think if you throw your dirt covered kid in the bathtub, the water absorbs the dirt and it becomes dirty also. Your kid wont be as clean if you take him out at that point, as if you drain away the initial dirty water and refresh it, and bathe the kid a 2nd time.

I think the best analogy one can present re to this issue is the washing of clothes. Say you handwashed your gear, then you want to rinse off the detergent and the dirt. You can rinse them 3 x with 5 litres of water, or you can wash them 1 x 15 litres of water.

It is intuitive that the 3 x 5 litres wash will wash off the stuff better than 1 x 15 litres. Same applies to extractions.

A Soxhlet is very similar. Each time it cycles through, the plant is soaked in newly distilled clean hot water from the boiling flask below until the Soxhlet is full, and then the water automatically siphons down to the boiling flask below, and then more water distills, fills the Soxhlet, and it siphons again. This happens over and over until you want to stop it.

The advantage of a Soxhlet over the percolator method is that the Soxhlet has a water cooled condenser above it that prevents distilled water from escaping the system. So you can let it run endlessly without touching it and the water will never boil away. For example, you can fill your Soxhlet on Monday, turn on your hotplate and cooling water, and then come back on Friday to get your extracted tea from the boiling flask below it. For a 1000 ml Soxhlet, it siphons about once every hour, so that would be equivalent to 96 individual soaks in the Soxhlet using freshly distilled water from the boiling flask below it. Imagine 96 extractions! You can be absolutely sure that 99.99% of everything that’s extractable was extracted.

In practice, a Soxhlet is usually not run for more than 8-12 hours. You usually just run it until the water in the Soxhlet looks clear. Once the water in the Soxhlet looks clear, it’s done. How long it takes depends on the type of plant being extracted and the water to plant ratio used. If the water to plant ratio is high on water, the extraction is always faster.




3 is usually the most efficient number of extractions when using the typical home style tea method where you boil the herb, strain, boil, strain, boil, and then strain a final time. I have extracted many herbs and found that 4, while slightly better than 3, is not really worth it unless the herb is very expensive. In most cases 3 boils in water will get about 90% of all the extractives. 2 is not usually enough.

It goes something like this:

1 boil gets about 50%
2 gets about 80%
3 gets about 90%
4 gets about 95%
5 gets about 97%
6 gets about 97%
7 gets about 98%
8 gets about 98%
9 gets about 98%
10 gets about 99%

Those are rough estimates and it varies by plant and amount of water used for each boil.

The reason for the curve is because the extractives that are easiest to extract, the ones on the outside of the ground up herd pieces, are extracted really fast in the first boil. The second boil gets far less because most of the easy to get extractives were already extracted by the first boil. Each consecutive boil gets the tougher and tougher to get extractives. After the third boil, most of the remaining extractives are the ones near the center of the ground up pieces of herb. Those are the hardest to extract because the water has a difficult time gaining access to them.

Lovely explanations.. thanks for sharing SWIYs hard won knowledge! An Infundibulum wonderful analogy - and 69ron, SWIM was thinking a Soxhlet did that - so LESSON learned. Thanks.

Thanks everyone , I really appreciate the time you have taken to help me have a better understanding .