The Home Stretch: Rh / Temp Control, LEDs, Sub-Irrigation in "Tents"

[HyDroid]

Terpene Retention

Terpene Retention

Some terpenes begin vaping off around 70-72F I believe? It definitely helps with terpene retention. Downside is you have to keep everything below that temp while trimming, drying and storing.

Vapor pressure varies non-linearly with temperature, so if you take two identical buds A and B and bleed off 10 grams of water from bud A at 80F and 10 grams of water from bud B at 70F, bud A and bud B will have different amounts of terpenes left.

The notion that colder temps retain more terps (i.e. that bud B will have more terps) would seem to be supported by a larger ratio of (vapor pressure of water : vapor pressure of terps) at lower temperatures, and the graphs indicate this could be possible.

I harvested a grow about two weeks ago and paid close attention to the temperatures as things cured. I managed to control the humidity as usual but my new place has less control over the temperature (that's another story). When the temps got to the upper 70's I could smell the terps a lot more strongly, especially as the amount of moisture in the buds got lower, and it seemed like higher temps meant I was losing more terps per unit of water purged.

All of this together really supports the idea that I should be drying and curing at 70F.

Do you have any trouble preventing mold at low temps during drying?

I'd like to nail this down and try to understand the contributions of vapor pressure, partial pressure, and from what I hear the boundary layer and diffusion rates play a role. Like, if the bud is at the bottom of a deep column with a fan blowing over the top of the column, and the proper temp and RH at the bottom of the column, does that allow the lighter water to escape faster than the terps, and reduce terp loss even further?

Or does it just come down to "colder temps retain more terps, have air flowing but not blowing."

Maybe someone has already covered this in a post... I'll take a look.

 

[Douglas.Curtis]

All of this together really supports the idea that I should be drying and curing at 70F.

Do you have any trouble preventing mold at low temps during drying?

I stay below 70F, usually around 68F. No, I don't have mold issues, as long as the dry is less than 2 weeks.

It definitely makes a difference, distinctly noticed by anyone who smokes it. Granted I also grow differently than most. lol

 

[HyDroid]

Myrcene

Myrcene

Yeah that's the key, the longer you let it hang dry results in a better cure. I mean, if you let it go for five or six day and then jar it when its still above 66% RH you will have a hard time getting rid of all that gaseous hay like smell. Anyway... I hang dry my weed at 65F / 65% RH until a stick of buds placed in a tall mason type spaghetti jar reads 67% RH or lower after its been in that jar for 24 hours. And besides all that, one of the most important things to remember when drying, is that once the plant has been cut, do not let the plant dry in a environment that is above 67F because if that happens the myrcene terpenes in your buds will begin to evaporate away.

https://www.icmag.com/ic/showthread.php?t=363372&page=6

Another corroborating post. So a 68 F target seems great and maybe 65 F could be reasonable but I imagine at some point it starts to slow down the drying?

I think I'll invest in a wine cooler before next harvest. Those can do temps in the 60's pretty well, it seems. I wonder how RH fairs in those without regulation.

Some people evidently use a freezer at the end of cure to leach the last moisture without messing with the terpenes as much (seems like when there is less water and partial pressure of terps is high this gets more important, certainly don't want to freeze "wet" bud).

And one step further is to employ a freeze dryer at some stage.

https://www.icmag.com/ic/showthread.php?t=200494

I wonder which of these options works well.

 

[GOT_BUD?]

I tried the freezer cure method. It was ok. It would probably work better if I had a dedicated freezer that did not have an auto defrost feature. I'd also recommend putting them in a cardboard box inside the freezer as well.

One nice thing about doing it was not having to worry about mold in my bigger buds. I could leave the colas together as they cured. And imo, the extra mass helps with cure. But have no real evidence to support my theory.

 

[CannaRed]

Great thread HyDroid!
Looks like I can learn alot from your future posts.

And Douglas- Excellent post a page back.

This looks like the start of an epic thread guys. Let's keep it up, I have nothing to contribute, but everything to learn.

 

[HyDroid]

Progress

Progress

Thanks for the enthusiasm and experiences, all! I'm already learning a lot from this thread.

Glad you're stoked too, CannaRed!

I tried some freezer curing on my most recent harvest during the last couple of weeks and kept my temp / Rh probe in there. It certainly let me dry faster but the Rh was low, like 45%. The result vaped well but was lacking terps, probably because these were small pieces. I also tried some in a sealed container in the freezer, and these seemed to retain more, maybe because that kept their local humidity up. I can see that this would really help those big buds that have a hard time with mold in ordinary conditions. Seems to corroborate your experience, GOT_BUD?, regarding the cardboard box. Next round I'll try again on some big buds with more Rh control.

I think that BOTH temp and Rh must be correct to avoid losing terps.

Also, I wanted to mention that I got two-way Rh control with Bovedas by discharging them a bit (drying them in my dehuey exhaust) as some recommend. If you use them fresh without ditching some weight, they will add but not remove moisture.

I don't think the salts in Bovedas bind terps but the paper might a little. I'll check on this though...

 

[HyDroid]

Freezer Cure, 2 Weeks Later

Freezer Cure, 2 Weeks Later

I left a couple of grams of that bud in the freezer and "forgot" about it. The freezer was down to 26% Rh. I didn't think it would firm up but it is rock hard. It's not crumbly, either, which was a surprise. If I remember, I may give this another shot next round, after all.

The freezer stuff is about as sticky as comparable stuff coming from the Boveda jars, but there is a lot of variance in this batch. Both are giving good vape hits on Crafties at 350 and 380 F. The Eclipse x Sativas is fluffier haze type bud while the Flo x Sativas is giving dense nuggets. Heavy lollipopping this round prevented any true popcorn but there is definitely some less dense stuff. I don't really know the distribution as at this point I will probably excavate the nuggets in small batches for use and otherwise leave them undisturbed, but it is all usable for dank hits on the Crafty so far, unlike some popcorn I have produced.

Bovedas seem capable of imparting the denseness of bud if genetics allow, but Boveda jars invariably seem to smell less dank than unregulated jars. It has been claimed that this is due to better trichome integrity in properly maintained environments.

Has anyone else noticed this effect with Bovedas? Is it an illusion brought on by humid air reducing apparent smell? Or is there something with vapor pressure going on that prevents terps from saturating the air and thus from escaping during burps?

These are some things I'm curious about.

 

[HyDroid]

Freezer Cure, Link

Freezer Cure, Link

Here's a thread reporting some positive results freezer curing:

Finish drying my bud in the freezer in my kitchen?!?
https://www.icmag.com/ic/showthread.php?t=186222

I am still liking my test freezer bud.


From my recent experiences It appears as if rock hard bud can be terpy or void of smell. I am curious what actually physically causes the hard "nugget" feel of certain bud.

I was wondering if it's the case that the hardness of bud is caused mostly by waxes as opposed to oils, and therefore will survive a more brutal curing than the sticky, smelly quality of lighter oils which may boil off even at low (> 70F) temperatures?

 

[Douglas.Curtis]

Missed that bit...

Yes, below 65 slows down the drying too much. Mold risk is significantly reduced by growing in a HEPA filtered environment. I've used clean air flow almost exclusively.

 

[HyDroid]

Adding Back Terps

Adding Back Terps

I have wondered for a while if there could be a practical way to regulate the amount of terps in buds much as Boveda packs regulate the amount of water.

It is straightforward to source food grade myrcene, beta-caryophyllene, etc.

I made a small pad of paper towel (2 inches x 2 inches) and encased it in some aluminum foil so that one side of the towel was exposed to the air. I put 5 drops of myrcene on the pad and enclosed the pad and a half gram of bud together in a mason jar.

In a matter of hours, the surface of the bud was sticky, as if the trichomes had absorbed the myrcene and become wet like live trichomes, and the jar reeked of mangos. The next morning, the bud was a bit firmer and tackier than it had been before infusion.

Note that the bud never touched the pad. Myrcene transfer was from pad to air to bud.

This method appears to work quite rapidly and is easy to overshoot. It probably requires a "reverse cure" to slowly infuse the deep parts of the bud, and a secondary cure to homogenize.

Further experiments with linalool and terpinolene (in addition to the prior two) yielded a rich landscape of flavors, ranging from fruity and candy to peppery, spicy, and licorice.

I am hesitant to do this too much as I don't want to OD on terps or cause any long term issues with terp overconsumption such as inflammation of the airways. Theoretically this is ok, within natural concentrations, but it is difficult to control the rate and amount of infusion, except by going slowly with smaller amounts of terps larger amounts of bud.

Does anyone else have experience with this?

 

[HyDroid]

Canopy, Bud, and GrowMau5 Initiator Shots: Spring 2019 Grow (Part 1/2)

Canopy, Bud, and GrowMau5 Initiator Shots: Spring 2019 Grow (Part 1/2)

I finally processed some shots from the Spring 2019 grow.

Here are three pics giving a panorama of the canopy.


Here is a dried bud shot. I'll post more of these from my accumulated shots after I sample more from the jars.


Here is a live bud shot.

 

[HyDroid]

Canopy, Bud, and GrowMau5 Initiator Shots: Spring 2019 Grow (Part 2/2)

Canopy, Bud, and GrowMau5 Initiator Shots: Spring 2019 Grow (Part 2/2)

Another live bud shot.


And here are some pictures of a bud in white light versus initiators.


And a shot of a bud in *white light plus initiators* versus initiators alone.


I got a decent amount of "monster growth" at the top. I attribute some of this to Flo genetics (a lot of DJ's Instagram shots seem to have this look) and cytokinin heavy treatments (kelp, coconut water, Universal 0-0-1), but I noticed that it seemed a lot heavier in the hot-spots of the initiators.

I think that the buds in the hot-spots of the initiators took on a more HPS feel in terms of inter-calyx spacing and bud maturity. There seemed to be a lot more of the "nested inflorescence" habit of bud growth. This led to some rock hard bud but also to some stuff that was fluffier than it could have been. It is all caked with trichomes, though.

Good dank stuff so far but I think I won't foliar feed in flower anymore. I was hitting the lower fan leaves all the way through and not the buds but I'm feeling that the wetting agent wouldn't be good for the buds even in collateral mist. It is coconut based and safe to eat and I used to think that if I could eat it I could clear it from my lungs but I guess we know that's not true now.

 

[Douglas.Curtis]

Awesome! Ty so much for sharing.