Hi everyone,

Quite often posts appear where the use of an espresso machine is suggested to aid an extraction - and for very good reasons since, in theory at least, they are used to quickly and efficiently to extract coffee, they could be used for an extraction of other plants. Sounds about ideal!

I had a espresso machine at my disposal, actually a machinetta, quite similar in shape and function to this and a while a go I decided to have a run and see how it performs extracting mhrb and syrian rue.

Experimental design

My machinetta could hold up to 50g of plant matter and for this experiment was either 50g of mhrb powder, 50g of whole syrian rue seeds or 50g of 50g of ground syrian rue seeds. The plan was to:

1. Extract the above mentioned plant quantities with 500ml water through the machinetta (passage #1)

2. Repeat the process on the very same material with fresh 500ml of water 3 more times (i.e. passages 2, 3, and 4)

3. For each machinetta passage, take additional measurements, like specific gravity (expected to drop in consecutive passages as less and less matter will be extracted) and pH (expected to rise as in consecutive passages as less and less plant acids matter will be extracted). The specific gravity of water is 1.000 and anything above that indicates that stuff is dissolved in the water. The pH of my tap water is ~7 and anything below that value means that acids are extracted in the water.

4. Take the plant material out and extract it with multiple water boils (i.e. 6x 1hour boils) to a presumed exhaustion point.

5. Extract alkaloids from each machinetta passage and for the extended water boils separately, but in parallel.

6. Calculate grand total yield and express the amount of alkaloids coming in each consecutive machinetta passage as a % of the total yield. (see attached table).

Results

MHRB powder
I start with this one, as this is the easiest to get out of the way; basically it didn't work. even though 50g of mhrb powder could be easily placed in the machinetta's bowl, there was no way the steam could pass through. The whole system clogged and the experiment was aborted for safety reasons. Interestingly, due to the high pressure involved, the mhrb powder coagulated to quite solid pieces that was as hard as wood, whose re-grinding was very difficult.

Most likely, the amount of mhrb used for the size of the machinetta was just too much. Things might have been smoother should I had tried a smaller amount, say 5-10g, but then again the way mhrb powder stuck together to such hard lumps was particularly discouraging to further experimentation.

Syrian rue seeds
After the 5 machinetta passages the seeds were boiled/filtered/reboiled etc 1 x 6h and reduced. The four machinetta passages and the boiled fraction were extracted in a manner similar to The Tao or rue extraction (https://wiki.dmt-nexus.me/The_Tao_of_Rue_Extraction).

Grand total yield was 6.425% of off-white alkaloids in freebase form for the experiments involving ground seeds and 6.38% of off-white alkaloids for the experiments involving whole seeds. (Endlessness, more results here indicating that grinding of syrian rue is not really necessary! )

Looking at the attached Table we see that the machinetta is useless at extracting whole seeds; passages 1 and 2 were devoid of alkaloids and only passages 3 and 4 yielded something, but then again only 15% of the alkaloids present. Obviously getting a total of 4*500=2000ml of liquid from the machinetta that hold only 15% of the alkaloids from 50g of rue is far from ideal... Interestingly, by looking at specific gravities and pH measurements of passages 1 and 2 we see that "something" is extracted off the seeds but it is not alkaloids.

However, the ground seeds counter-experiment was far more productive. The first passage extracted ~43% of rue's alkaloids and the combined four passages amounted to retrieving 72% of the total alkaloids from the ground syrian rue. This means that for 50g of ground rue one can have 72% of the total yield in 4*500=2000ml of liquid. Not bad, even though I'd be happier if the total yield was 90%+ from the machinetta.

Conclusions

I am ambivalent to the use of an espresso machine for extractions. MHRB lumps badly and ground rue extracts OK-ish but not better than the methods we already have available. Something that needs to be given more attention is that maximum capacities were used in this series of experiments, maybe because I have extraction/purification in mind rather than concocting and consume the resulting tea as-is. The latter means that should I had used, say, 3g of ground syrian rue I might have gotten 90%+ in the first machinetta passage. But then again the resulting rue concoction might have to be reduced to a drinkable volume as gulping half a litre of syrian rue tea is not everyone's cup of tea...

Excellent work Infundibulum. I notice that with the whole seeds the efficiency increased with each successive pass until it is roughly the same as ground seeds, although the yield lags behind for 1 or two passes. Might this not just be because the seeds have not fully softened and swelled in the water yet, and as they do so, the extraction would be the same as ground seeds ? Suppose one simply leaves the seeds for a day or two in water to soak and swell up, then extracts as they would with ground seeds ? It could certainly make filtering a lot less of a pain.

Thank you Orion,

I too think that the first two passages of whole rue seeds sort of "lubricated" and facilitated the extraction, but then again not to an acceptable degree. After 3 passages of water, the fourth was more yielding (8.7% of total), yet not as high as the first passage of ground seeds (~43% of total)

Maybe if the the whole seeds were left to soak for a day or so yields would be comparable to ground seeds, but on the other hand, since the technique of using the espresso machine overall gives mediocre results, I do not see much point at trying to tweak it!

Better off using it for mushrooms. So I'm told

Another thought: have you tried roasting/toasting the seeds first? That's what we do to coffee beans, after all!

Stuff the perc, I just can't stand filtering normal ground rue extractions