flue/air curing

[LeftyRighty]

This is a question that has had my interest for a couple years. Can one flue-cure for just the intial phase of yellowing the leaf, then finish with air-dry ??? What I'm considering is to use the kiln-fermenting chamber, with the green leaf in hands or bundles, starting at 100-105 degrees, increasing to 115-120 over a day or two, until the leaf is yellow/brown (except the mid-rib), then remove and hang to finish the cure and drying as with air-curing.
When hanging to finish dry, the leaf would have to be strung in a manner that allows free air flow, to prevent mold and allow thorough drying; i.e., taking the same precautions as normal air-curing practices.

This would solve the problem I have with color-curing on warm days and low ambient humidity, and would be an end-around to prevent green-dryed leaf. I have lots of leaf, a small kiln-fermenting chamber, but lots of hanging space. There is no way that I can flue-cure much of my crop if it's ties up the flue-kiln chamber for about a week.

Although it probably doesn't matter much, but, would the end result taste/smoke like a flue-cured leaf, or air-cured?
And, of course, I understand that the process will have continue with fermenting and/or ageing, after drying.

(edit) The only reason I have not tried this before is that my current kiln is really crappy – doing good just to say it gets/stays in fermenting temperatures. I am building an improved model, with electronic controls to maintain proper temp/RH. Hoping to have it ready by mid-July.

 

[Chicken]

the old propane drying barns, dried baccy leaf starting at the green phase,

the day it was picked is the same day it got racked and put into the barn,ive picked, and loaded many barns
this barn uses heat that is blown thru the racked baccy

unless you can get a lot of steady heat,,, and get this heat circulated thru the green baccy. i dont thin it will work

having green hands tied toghter, and trying to dry it, like that,

i believe you are asking for mold,

allthough in stick drying barns, they tie 3-4 leaves in a hand fashion, 3 on one side of the stick, 3 on the other side, and the final product is a baccy stick, with actually a lot of baccy hanging from it,

so your idea is close to stick drying,, i'd just keep the hands to no more than 5 leaves,

and be on the look out, for mold,,,and keep all the humidity out of the area,,, a dry heat is what your looking for,

 

[leverhead]

As I think I understand it, the ventilation/relative humidity is just as important as the temperature. The first phase is to let the lief do it's thing, getting rid of the green and converting the starches to sugars while still removing some of the moisture, just not too much. The yellowing is a different thing but serves as an indicator for the conversion of the starches to sugars. The second phase is to remove enough moisture before 130 F so the lief doesn't scald/cook as the temperature goes higher, to 165 F. The third phase at 165 F and very low RH finishes drying/killing the stem and stops whatever else that was going on.

 

[LeftyRighty]

Chicken.... I'm not trying to dry it in the kiln - just yellow the leaves. Then I'll hang in the shed to dry.
What I want to do is keep it in a moist environment, with increasing heat, until the leaf yellows. What I don't want, and am trying to avoid, is the leaf drying green. Yes, I'm thinking small leaf bundles. The kiln chamber will have fans to keep the air circulating.

It's my understanding that mold does poorly above 105 degrees. If I prime my leaf in the AM and hang in the kiln, bring to 105 by early evening (it will take that long just to stabilize the temp in this kiln), then bump to 110 to late bed time, then set for 115 overnight, maybe bump the temp to 120 the next AM until leaf is yellow. The RH will probably be in the 90+ to 100 during all this, because of all the moisture in the leaf. After the leaf is yellow, I'll hang in the shed, with an osillating fan, to dry. Once it's yellow, I don't care how fast/slow it dries - just know I need to be viligent in preventing mold.

I am not going to go above 120-125 degrees in the kiln with this leaf. That way, I still have all the goody enzynes needed for fermenting and aging.

 

[deluxestogie]

LR,
Last season, I built a fire-cure chamber from a galvanized trash can. (The entire post is on HTGT).

The angle iron is simply resting on two bolts attached to the can rim at opposite sides, and can be lifted out.

This particular trash can had a number of holes bored into the bottom, to admit smoke. I discovered that if the can was positioned on top of the black Brinkmann smoker, with no fire, direct sunlight would heat the upper can to about 115ºF for most of the day. Regulation of humidity is controlled by adjusting the lid opening. Probably if the can itself were spray painted flat black, it would reach the same temperature without the Brinkmann.

The two bungee cords prevent the assembly from toppling over in gusty wind. The thermometer is a "grill" thermometer from Walmart.

Since I was trying this on Sherazi, a leaf that seems to easily dry green, I was pleased that it fully yellowed in the 115ºF solar heat inside the can in about 1 week. Leaf was strung back to back on 17 ga. wire, about 35 leaves per wire. After the first wire of leaf was hooked onto the angle iron, a second, similar wire of another 35 leaves was attached alongside it. So, it was doing ~70+ medium-sized leaves. No fan; no forced air; only convection. The difference between color-curing in the shed vs. color-curing in the can is the better control of humidity.

So, I believe that a galvanized trash can, with the two bolts attached to the rim, and painted black, can serve as an effective means of shortening the color-curing time by use of direct solar heat. The leaf is unlikely to mold during the yellowing phase. If the ambient humidity is high at night (in your locale), then the lid would need to be fully closed at dusk, and set ajar after sunrise. You really don't even need the thermometer.

I am hoping to use this method (no holes in the bottom of the can, but with fire in the Brinkmann) to try a poor man's flue-cure this summer. Probably, two days of supplemental heat at the start would accomplish a color cure.

Bob

 

[leverhead]

I'll have to check the rest that post! Great stuff! I like your "fasteners".

 

[BarG]

That is a realy cool fire cure chamber, I particularly like the perforated hanging bar. I find those t-post fasteners for barb wire fences with a hook on each end particularly helpful when hanging anything for smoking as I have a ton of them. I'm looking forward to seeing leverheads flue cure brainchild when its completed. If it works It would be great for smale scale. Keep us posted on your progress leverhead And give me a holler if you need a wooden type barrel, your not far from me and we could whup one up in an afternoon.

 

[Chicken]

i have my kiln up and running, {PICS TONIGHT }

and i threw some green leaves in there, to colour cure, to see how it goes,

i havent went to see what temp. it is resting at, i just fired it all up,

start cook time, 12 p.m.{80 f temp.} i'll update this post with time, and temps, and pic's later,

1;12 pm.{ 100 f temp }

 

[LeftyRighty]

Oops!
I messed up big time – should have done a bit of research before starting this thread. After reviewing resources on commercial flue-curing, I’ve learned that I’m way off on my approach to an initial flue-cure.

What I should be doing:
Ripe green leaves should be dry before putting in the kiln – no surface moisture, pick leaves in mid-day so there is no dew, and not on rainy days.
Start kiln temperature at ambient (outside) temp, and raise at 2° per hour to 100°F. I’m assuming my 5° over a 2+ hour period is essentially the same. Keep temp at 100.
Maintain relative humidity at 80-85% throughout the entire process. I need to be sure that I’ve got enough free ventilation through my kiln, and to monitor the RH.
Arrange fans to insure that good circulation will maintain uniform temp/RH within the kiln.
It should take about 2-days to yellow the leaf, but may vary.
This to allow the biological and physiological changes for a proper cure.

Maintaining temp will be easy – may be a pain to keep proper RH and ventilation, but may be worth the effort.

Also learned that plant cells die at about 113°F, which produces browning or scalding. Interesting, because when the ambient temperature goes above 100° here, the temp in my garden shed, where I cure leaves, has gone to as much as 115°. Looks like I need to vent my shed more on hot days.

I’m still planning on hanging my leaves back in the shed after they’ve yellowed, to complete the curing and drying. Back to my original purpose – avoid green-dried leaves from air-curing in the shed. Just going to do this with the flue-cure Virginia strains. I’ve got 110 flue-cure Virginia plants in the ground, so a 2-3 day cycle in my small kiln may not keep up with ripening leaf.

 

[Chicken]

^^^^

that is all true,

but im going to document, the drying of green leaves to see what happens, last year i air cured, this year i have a big kiln, so we will see what happens,

perhaps if nothing more, it may speed up the process, of colour curing,?

 

[leverhead]

Also learned that plant cells die at about 113°F, which produces browning or scalding. Interesting, because when the ambient temperature goes above 100° here, the temp in my garden shed, where I cure leaves, has gone to as much as 115°. Looks like I need to vent my shed more on hot days.

"Google" up "wet bulb thermometer". It would better reflect the leaf temperature.

 

[Daniel]

I am looking into this also. I am thinking I will just use the kiln I already have and increase the temp. I am a bit concerned that some other heat element may be needed. I an not sure how well a light build will last at the higher temps. I know humidity control can be as simple as a vent that opens and is controlled by a humidistat. I already have a temperature controller. I have to find the humidity controls. IF humidity gets to high even a small hole will lower it in seconds. our air is so dry it sucks the water out of a saltine.

 

[leverhead]

I am a bit concerned that some other heat element may be needed. I an not sure how well a light build will last at the higher temps.

You might try appliance bulb(s), They're pretty rugged.

 

[BarG]

Have you ever touched an outdoor flood light bulb? They get pretty hot. The heavy ones.

 

[driftinmark]

i found this today, hope it helps.........

http://pubs.ext.vt.edu/436/436-048/436-048.html

check out the curing pdf, its really informative!!!!

 

[LeftyRighty]

yeah, that's the source I was using. Haven't got my new kiln completed yet, but I've got 2-3 weeks to get'r'done.
I am still going to just hold at 100 degrees & 90 RH, until they yellow, then finish with an air-cure.