Learned some lessons about rosin pressing with dry sift, thought I would write them down. I learn by doing, which means I make a shit-ton of mistakes. Here are two of them:
- Point Loading the Filter Bag.
- Leaving the Filter Bag Open.
For these lessons, I used about 40 grams of dry sift, or about $1400 worth by LP pricing. Overall it was back to back failures but not all was lost, I recovered a minimal amount of rosin. Did I recover the most important thing, my pride? Who knows? I don’t mention it again, but I do make a few poop analogies, so you can read between the lines there.
I don’t like to trim cannabis, especially the smaller buds that aren’t really worth the time. During flowering, I’ll strip the lowers right off but after 5 weeks, I just let them grow and deal with them when trimming. So I use the abundance of lowers and other trim for dry sift hash.
Although the cannabis feels bone dry to the touch, the dry sift has water content left, so it compacts easily by hand. I do this in a small plastic bag and roll it to a sphere so it looks extra marvellous.
In my first trial, this is what I used in the rosin press. Just chucked it right in the bag, real lassiez-faire, like I’m on TV where everything works out perfect. What came out was more Rorschach than Rosin, to me it looks like a diaper that couldn’t handle the pressure, you may see a butterfly or a rabbit.
So I posted that picture on Twitter and received some good advice from Jon Grow that I should keep the dry sift non-compacted and slowly increase the pressure and temperature.
Armed with this information, I made another attempt, this time with even more dry sift. Progress was made over the previous run but was still a massive failure overall because I didn’t close the filter bag.
It’s now crystal clear why you would close the bag when pressing dry sift. Heating dry sift and applying pressure releases the liquid components. If you put liquid in an open container and place it on its side, the liquid runs out the open end. This likely seems obvious to you, I’m right there with you, seems obvious to me too, now.
Following Jon’s advice, albeit poorly, I pressed the material at increasing temperatures and pressures, sigh, each time with the bag open. The first two presses were actually good with minimal leakage. I recovered some blonde rosin that is solid at room temperature and somewhat chalky to the touch. Pressing the dry sift above 200F yielded something like diarrhea after double XL Slurpees, it just went everywhere. And what do you do when that happens? You put on gloves, take your socks off and do a humble clean up.
From the 19.9 grams of dry sift, I recovered about 4 grams of rosin. I didn’t scrape the dry sift leakage, I’ll just run it through Coconut oil to recover the material. The 20% yield was dismal. If performed properly, the yield would have doubled or tripled.
Don’t read into it, but the first gift my in-laws gave me was a sewing machine. I really have no excuse for not sewing the bag closed, which I think would have solved this problem and made for a better end product. Lesson learned for next time.
The initial problem, point-loading the filter bag, was solved by keeping the dry sift powdered/granular, so thanks to Jon for that one. I surmise when pressed, the lateral motion of the dry sift against the filter bag caused enough friction to tear the fibre, causing the fantastic blow out.
Once I get the procedure down, I’d like to start tracking % recovery against pressure and temperature settings. For now, I’m going to concentrate on bag closing and getting a successful run under my belt.