At What RH To Stop Reducing Humidity In My Curing Fridge @ 16C To Get 62% In Jars At Room Temperature

[MidgeSmith]

Ok, so I am using my beloved curing fridge made to the specifications set down by FarmerPalmersNT and noticed last time, that the weed was waaaay drier than 62% at room temperature as I stopped reducing humidity in the fridge when the inkbird said I had I got to 62% RH at 17C.

So, as I want to continue curing my weed in the jar after fridge drying / curing it, I want to figure out what the lowest curing-fridge RH I should go to and hold it before moving it to jars at 20C to carry on the cure over the following months.

The questions start here:

1) The curing fridge is 16C (I wanted to try it at a lower temperature because A) I can as it is cold everywhere, B) I feel it will make even more certain that no terpenes VSCs are lost unnecessarily and C) Mould will find it very hard to get a foothold at that temperature.  These assumptions may be wrong and counter productive in some way, feel free to comment.

 

The Jars as I say, will between 16C and 21C in my room, depending on whether they heating is on or not!  However, ideally, I'd like the RH in the jars to be 62% at 20C/21C.

 

2) I did a quick calculation online and it said that to have an RH of 62% at 20C, I'd need the RH in the fridge at 16C to be 80%RH!  That can't be right can it?

 

3) I can't imagine people will think 'just go down to 62% anyway and it will be cured enough when it is finished, who cares if it carries on curing afterwards.  However having asked similar on the Fridge Curer thread, nobody seemed to care or think it mattered.  That leads me to feel like I am over thinking it, but I can't help but think I'm losing out on the last few percent of goodness if I don't know...  I haven't the capacity to do an A / B test, so it is all or nothing. So the final part of the questioning is:

 

Should I just stop dropping the temperature at more like 70% RH at 16C, hold it at that point for the remainder of the fridge curing time and then jar it and move it to room temperature or would that somehow risk compromising the cure?

Any answers to these weird, tenuous and desperate, nerdy questions would be appreciated by any scientific minds or people who have experimented thusly with curing!

Cheers!  Midge.

[MindSoup]

9 minutes ago, MidgeSmith said:

I am over thinking it,

This. 

 

I think you've put more thought into this post than I have about building 2 fridges and drying 18 months worth of crops . 

 

Put it in the fridge, gradually bring down the moisture levels until your happy, trim it, chuck it in a jar. There's a million and one ways to go about this and about a million will probably work fine. I do it slightly different every time, what can I say I don't take notes and consistency is not my strong point . 

 

Also it's not that no one cares, more that it's already been talked to death and people are asking questions that were answered 2 pages ago and 2 pages before that etc, it just makes the thread messy and confusing. Farmer P actually mentions that in a comment and then stopped following his own thread because it was getting so tedious . 

 

There's no rule book this is some frontier shit we're playing with , it's not for those that need to be led. 

 

All love btw, I'm just blunt AF and a bit cunty is all. 

Edited January 27 by MindSoup

[MidgeSmith]

But @MindSoup oh Mindsoup. I have relied on much of your frontiersman reporting for advice. Seriously though, not reading it as cunty or being 'offended' by a blunt answer, just want some science and experience without risking my own meds lol. Thanks for answering anyway, I always enjoy interacting with you.

 

Much of what was said on that thread seemed to suggest that if you ever open the fridge before the weed is perfectly finished, the world would explode and all my teeth would fallout.  I'm very experimental but always nervous to take the first leap of faith.

 

I guess what I am going to have to do is ignore the explosions and lost teeth and... OPEN THE FRIDGE after holding it at 70% for a while, taking a jar full out and jarring it to see what it does at room temperature.  I can always bring the rest down to 62% in the fridge if that doesn't work out.

[MindSoup]

Oh good I'm glad I'm not ruffling any feathers. 

 

It's (probably) better to leave it shut the whole time, in the same way it's  probably best to keep your tent closed all the time, but of course we look.in our tent all the time and mess up the environment for a bit. I don't think I've ever dried a crop without opening the door at least once. Plus while your learning how it works I don't see how you could know without opening it a few times and checking. 

 

As far as the science goes I'm not really 100% on that, as you say 60% at 14 is not 60% at 18. All I can say is that it works and IME at least you don't have to be super precise or consistent. Sometimes I only fill one shelf, other times I can hardly shut the door, sometimes it's hot in my flat and the fridge struggles a bit, sometimes it's really cold and it hardly has to come on at all. All of these things effect how the dry will go, so as usual it's about getting a feel for it. 

 

Like I say this is a fairly new technique, I doubt there's even 100 of these DIY fridges in existence, so we're figuring things out together, have a play about, report back etc. I've fucked up a few dries and the bud is still decent at the end, pretty hard to actually ruin the bud, even when a relay sticks and the dehumidifier is stuck on for 4 days

( keep an eye out for that btw).

 

[MidgeSmith]

Yeah, fair enough.  I guess cannatrol users have it so easy they cant teach us much but they're the closest.

(edited to add that) There's an awful lot of cannatrol users not happy with factory settings and finding it hard to get the cure they want using their bloody expensive units, so its all about the experiment for everyone I guess.

 

I will experiment a bit, I am just a bit nervous when most of the crop is in there...

Edited January 27 by MidgeSmith

[MindSoup]

Yeah I did try an idea I'd got from cannatrol (or somewhere) it's in the thread, can't remember how it went but nothing has come out ruined just yet. 

 

If you're worried I'd say err on the side of caution and take it out  sooner rather than later, can always put it back in if needed, better than finding out where waaaay to dry is. 

 

You've got this dude, I know it feels weird but once you've done it a couple of times you'll relax into it. Bit like pegging.... 

 

.... Or so I'm told . 

Edited January 27 by MindSoup

[MidgeSmith]

Ha ha! Cheers

Yeah, I'll just stop it earlier.  I'm changing the slop this time.  2% per day from 90% down to 80%, then 1% per day down to 70%, then I will check how it is feeling.

 

I am particularly keen not to let the Afghan go too far as I had two plants, one that went purple black with a small yield, but buds that are covered in a billion trichs and smells like rose petals and fruity spice (that one is in the fridge) her sister has much bigger buds and much more of them, but virtually no trichs and a very low level smell (at least 2 weeks behind and still in the tent).  I want the small fridged one to keep all her glory as her sister smells destined for edibles or a bubble-hash run if she stays disappointing.  I've dropped the temperatures and boosted the UV on her to try to encourage her to trich up, but as some of her hairs are already brown, I think the chances are slim.

 

All the best fella and thanks for re-engaging.

[MindSoup]

That sounds about right, one thing I'd suggest is let the fridge set the starting point. Fill the pre cooled fridge, leave the dehumidifier off, let it settle for say 2-3 hrs and you'll see the humidity will level out, normally in the mid 80s. Then start knocking it down from there. 1%, 2%, 5% at a time? it shouldn't really matter too much as long as the whole process takes long enough, just make sure you don't set the step so big that the fridge can't keep the temps down. 

[MidgeSmith]

Yeah, that's exactly what I did.  It started at 89% and is down to 81% towards the end of the third day.  I figured once I'd taken the top 10% off, I'd cruise down slower.  There's something about taking it slow in the 80s% that I find a bit too unnerving lol.

[MindSoup]

Sounds like you know what your doing. I never stress about the high humidity TBH, I figure the buds moisture content will only drop a few % with conventional drying so it's the same speed as normal, ask me again in 10 years though, maybe it'll bite me in the arse eventually. Either way as long as it takes 2-3 weeks in total your golden. 

[MidgeSmith]

I figured out why my question is nonsensical in the end and why the question I was asking probably confused anyone who considered it at all, because of my wording.

 

I was forgetting kinda, that RH only relates to the capacity of the air to hold the moisture, not to the humidity of the bud.

 

I want to get the bud humidity down to (12% ish iirc).

 

The capacity of the air around the bud in the fridge at 62%RH @16C means that it can still hold enough water leaving the bud to raise the RH by 38%, the same as air in a jar at 62%RH @20C can be raised by 38% before it is saturated.

 

The beneficial difference here is that at 16C the water should leave the bud a little slower due to the lack of 'evaporation' and the air holds less water at 16C than it would at 20C.  I am imagining that this means slower extraction of water at lower temperatures. It has to an obviously does.

 

Just because the ambient air would have a lower capacity to hold moisture at 21C than it did at 16C and so the RH would drop a lot if the fridge were warmed up without being opened, it doesn't mean that with an ambient humidity of 62% at 16C it will make the bud too low.

 

There is zero reason to assume that the ability for the cold air to remove moisture from the bud would be greater than warm air (which I assumed because raising the temperature of the same air shows it has a lower RH, it doesnt mean it is drier when it is cooler at all). In fact the opposite is true.

 

As you said, the thing to do is check how dry the buds are as the RH in the fridge approaches 62%.

Edited January 28 by MidgeSmith

[5Lip]

On 27/01/2024 at 13:40, MindSoup said:

 Sometimes I only fill one shelf, other times I can hardly shut the door...

Interesting read, I've done a couple of drys in my fridge and have to say (even though I know its not perfect) its levels above the 'grow room' dry. I was actually about to post a comment about over filling the fridge as this run looking good but reading @MindSoup post has put my mind at ease somewhat.