I have seen a lot of talk of stem rubs.
I have tried to them myself and I do smell “some” terps, but I never smell anything that I can directly correlate to the final cure.
Maybe I dont rub them the right way. How hard do you rub?
What age should the plant be?
What is the benefit?
M
Subcool has a good video about this. If you search YouTube. His channel was the dank I think. This is from recollection from years ago. I think most stem rubs are for males(breeding)
From my limited experience you get an idea on how smelly a plant might be but not the final flower.
I just like to smell my fingers after, it’s intoxicating to me 
Plus I really like to run over to my wife and hold up two fingers in front of her nose and say smell this 
Afroman style
Bodhi used to use a different peace of paper on each plant to rub the stem, that way you can smell many plants and not get a medley on your fingers.
I get to understand the nature of the plant through stem rubs - subtle/feminine or dominant/masculine.
I also pay attention to how the smells change, or stay the same, through the grow.
Once you get some resin glands on the stem and fan leaves, you can see what the flowers will be like - generally
Stem rub isnt the only selection method i use, but its on the list.
Effect
Resistance
Roots
Structure
Smell/flavor.
Pretty much in that order.
Its hard to nail down effect, its easy to nail down smell
the good ol smell my finger bit! but now it really is worthwhile to smell them fingers. i love ya doc, but can i just rub them myself and smell my own fingers? hahah!
i agree with you though. i just like smelling the scents. it’s such an interesting puzzle almost, to try and correlate the smells you’re getting with things you’re familiar with. it’s all in an attempt to know these plants better.
at this point in time, it all seems so foreign and strange to me with some of the odors i’m picking up. i almost don’t have words for the smells. like i can only say this one plant smells “bitter green”.
but i imagine as we get to know the plants better, and just have more experience and time, it’ll almost be like you can be walking along nowhere special but some smell hits your nose and immediately you’re teleported to a specific place, time or experience.
so in that way, i feel like rubbing stems is like giving your babies hugs and really getting to know and love them.
i wish this were the way it is for me @Wuachuma , but i feel like my sense of smell is so rudimentary right now. i’m gonna keep at it though, and keep smelling my plants. at some point i figure it’ll make sense or something in my body will click with it.
the thing i like about rubbing with my fingers is that i get to feel how sticky the plant is. also i can bend it and test strength and rigidity as well. it’s like when you hug your parents or something and you’re patting them up to make sure they still seem healthy.
to combat the terpenes blending, i will spray my hands with iso after each plant.
i’ll be curious to try out a piece of paper though. my natural inclination is to say your fingers would catch more scent. but the paper would be more neutral to start out with? i dunno. i’ll try it out.
Contamination aint much of a problem til they get resinous.
My sense of smell is shit, weak and not refined. But every few plants really talk to me.
all I can think of is The Rock now
Sometimes I rub the stem when I get impatient because the plant isn’t giving off much smell.
I prefer to rub the leaves if I’m trying to judge the smell of the plant.
Imo, Rubbing the leaves is a better gauge to judge what the plant will smell like versus rubbing the stem.
I compare the leaf smell to the smell of the trichs because I prefer for my plants to be just as loud as their trichs so there will be no muffling between them.
it’s sucks when a beautifully smelling plant smell is drowned out by the smell of its trichs. So when people smoke bud like that, often they will say that it doesn’t taste like it smell.
So you’re saying that trichomes smell, interesting, never heard that one before. Would you elaborate more?
Aren’t keif and trichs the same. Doesn’t your keif have it’s own smell even though it’s separated from the plant.
Dry sift, bubble hash, rosin all have smells because if they didn’t, you wouldn’t be able to taste them.
The taste and smell of the trichs are different than that of the plant. Loud plants reek long before any trich form on them.
Louder plants can produce much louder trichs than the plants that barely have any smell to them.
Plants that you have to rub, or brush up against, or move to smell are no where near as loud as plant whose smell permeates the area long before you get in touching distance of the plant.
For instance, I have some DJ short blueberry that barely has any smell even when I move them. Until recently, rubbing their stem didn’t produce any type of smell so I was really worried about them.
The way people speak of DJ shorts blueberry, I expected more. So I already know that even with trichs, my blueberries aren’t going to smell worth a flip.
A good real life example would be… the other day I “accidentally” did a stem rub when inspecting a plant & then coincidentally got my hand near my face right after… & BAM! 
Lemon cleanser! 
…so I immediately checked the sister plant…not the same intensity at all but the same general 'limoneney smell. The smellier stem plant is flowering a bit slower & has a lot less visible trichomes, whereas the less smelly one is frosty looks 2 weeks ahead of her sister. 
One of the potcasts I was listening to recently had a breeder saying that stem smell is mostly an indicator of the “loudness” of the bud. 
So my point is, when you “get one” you’ll know why! 
It will be interesting to compare the final product in a couple of months & too bad I can’t afford testing & am in a not-so-legal state.
You can mail in samples to certain labs actually. Tests aren’t too bad, just for potency. The at home tests aren’t super accurate, but have gotten better.
I have honestly never had any good pure terpenes from cannabis, they always taste a little off. They steam distill them, so if you want to go try them, thats the true “essence,” of the living plant aka essential oil…however, As soon as the plant is harvested, the terps are oxidized, so it doesnt seem like a live plant smell would correlate to the final product we use as a drug.
Just my thoughts.
Theres cystolithic trichromes and unicellular trichs that are more found on the stem, then theres capitate and bulbous trichs thar are more found on fan and sugar leaves as well as high concentrations on the flowers.
When you rupture their cellular wall, you release volatile (aromatic) terpenes
The stem rub is a mechanical action of doing this.
Some growers are against stem rubs because it crushes these trichromes along the stem, which do in some way assist in airflow up and down the stem…plus, you can see where a person rubbed the stem by the ruptured trichs.
Yeah, that’s why I don’t see it as correlating in any way, those volatile smells will not be the same when the plant is harvested for our purposes. I guess that’s partly why the Hemp derived terpenes never really smell like the buds or any drug products, because they are the essence from the plant itself.
Would be interesting to compare the terpene breakdown between distilled terps of a clone vs the bud from the same clone vs fresh frozen.
i only do it to sort of look for anything that stands out. I’ve rubbed so many they smell the same and don’t really tell me anything. But every once in a while you do a stem rub and there is a unique aroma and suddenly you care more about that plant.
The precursors for flavor products are contained in stalks, leaves. You can learn to recognize many flavor precursors/ conjugates. I was recently listening to Heimie Cheeba discuss breeding RKS with an OG, how the end product is much louder than RKS itself. Of course it is. When you mix thiols (skunks) , and acetates (ogs), you get a compound containing thioacetic acid, which has the lowest detection threshold on earth. So learning to detect functional groups is fundamental to breeding Cannabis without a big fancy company in New Zealand helping out.
The biometric nose is vastly superior to digital sniffers. However, most flavor precursors are bound, inactive, and must be liberated.
This is a concentrated stem extract. Smells like if christmas was made out of stems and hash. Until you apply the proper enzyme. Then you are transported to the past. When Cannabis contained these enzymes naturally.
We have developed liberator kits to free the lost Cannabis profiles from “winterizing” waste streams. We are creating the first truly medicinal cannabis extract of the 21st century. Ghost of Sub Extracts. In remembrance of Subcool, who died after dabbing Grow Science concentrate (an Arizona medical marijuana company who’s product is loaded with foreign toxins).
Low terpene/cannabinoid toxicity, high flavor, targeted medical value. Zero geraniol pathway products. Homeopathy: choose the strongest chemistry, not the most abundant lab numbers or most recognizable commercial colloquialisms.
The Cannabis community has not seen medical grade extract in decades, since the narrative went to thc and fruit peel terpenes (which are disgusting precursors to flavor molecules , not flavor molecules themselves). It’s time to show the world what the other 70% of their lab analysis can do.
You are claiming he didn’t die because of his rare autoimmune disorder but rather because of a single companies product and are starting a company based on his name that sells extracts?
That’s at the least F’d up, and at the best just plain dirty.
I like science, but I can learn from other sources just as well.
Thankful for the ignore button 
Tell me how you utilize boron for your stem extractions.
Edited for spelling
I have a plant that brings out the terps in the crosses that I make with her. It’s amazing how she transforms strains that have barely noticeable terps to strains whose aroma can be detected from a distance. She can make a plant go from being dull and lackluster and turn them into something live and brilliant like eating fresh fruit. No lab, real live working genetics that are doing what they do best. Gem come in all shapes and form.
