AmaxB- Flue Curing Tobacco at Home: Wins & Fails

[AmaxB]

I built a grand chamber to Flue Cure my Tobacco it has been tested and proven to work.
A link to my chamber build thread - http://wholeleaftobaccollc.com/forum/showthread.php?2095-Curing-Chamber-from-the-box-up-My-Build
Now I must establish my process.
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The photo above is from my second batch while the tobacco looks good it is not 100% there is some green vein in a few of the leaves.
My first batch was a fail we won't talk about it....

Am running my third batch now and have started drying the leaf. It has become clear to me that my approach to yellowing is wrong, I am
still having problems with green veins and in an effort to solve it have extended my Yellowing Phase. I have learned this can and will lead
to poor leaf.
I can dry the leaf and stem no problem.

Will try a new approach to yellowing with the Forth Batch below are my notes for yellowing the third batch.

[FONT=&amp]8/26/13 3rd Batch African Red Flue Curing[/FONT]
[FONT=&amp]Tobacco is ripe but many leaves are slick at the butt.[/FONT]
[FONT=&amp]Started 6:30 PM[/FONT]
[FONT=&amp]Shut off Humidity Control and set temperature to 74F[/FONT]
[FONT=&amp]7:30 PM [/FONT]
[FONT=&amp]Set Temperature at 80F & turned humidity control on set at 93%[/FONT]
[FONT=&amp]8:30 PM[/FONT]
[FONT=&amp]Set Temperature at 90F humidity 93%[/FONT]
[FONT=&amp]10:00 PM Set Temperature at 98F humidity 93%[/FONT]
[FONT=&amp]11:00 PM Set Temperature at 103F humidity 93%[/FONT]
[FONT=&amp]Will look in on things in the morning...I want Dry Bulb of 93-95F & Wet Bulb of 93F[/FONT]

[FONT=&amp]8/27/13[/FONT]
[FONT=&amp]1:40 AM checked things[/FONT]
[FONT=&amp]Heat Box reading 99F RH 91.6% / Dry Bulb 94F & Wet Bulb 92F in the morning I may drop humidity a little.[/FONT]
[FONT=&amp]11:00 AM check[/FONT]
[FONT=&amp]Increased heat box temp from 98F to 105F - Dropped humidity to 87%[/FONT]
[FONT=&amp]Bulb Readings Dry Bulb-94F Wet Bulb-92F [/FONT]
[FONT=&amp]3:00 PM > Bulb Readings Dry Bulb-96F - Wet Bulb-92F -- Due Point 86%[/FONT]

[FONT=&amp]8/28/13[/FONT]
[FONT=&amp]10:59 AM checked things no changes needed leaves are going yellow[/FONT]
[FONT=&amp]Am thinking of increasing temp.[/FONT]

[FONT=&amp]8/29/13[/FONT]
[FONT=&amp]8:22 AM leaves are 75% yellow and uniform, No control changes made[/FONT]

[FONT=&amp]Readings Dry Bulb-98F - Wet Bulb-92F -- Due Point 80%[/FONT]

[FONT=&amp]Put wet towel on floor to bring humidity up a little....[/FONT]

[FONT=&amp]8/30/13[/FONT]
[FONT=&amp]12:00PM Am trying to get a perfect yellow[/FONT]
[FONT=&amp]Set fan speed to low my leaf is limp so air can move increased humidity to 90%[/FONT]
[FONT=&amp]Temperature is 96F Dry Bulb[/FONT]
[FONT=&amp]Am all most there I want little brown on the leaves & little green in veins looking for [/FONT]
[FONT=&amp]100% yellow. When I have this or very close to it start wilt - dry phase.[/FONT]

[FONT=&amp]8/31/13[/FONT]
[FONT=&amp]Veins refuse to yellow if I don't start drying I will damage leaf[/FONT]
[FONT=&amp]Increased temp 2F starting Wilt/Dry[/FONT]
[FONT=&amp]Increase 2F every hour to 118F and Hold 3 Hours increase to 135F @ 2F per hour.[/FONT]
[FONT=&amp]Wet Bulb 100F to a Dry Bulb of 118F / Wet Bulb 105F to Dry Bulb of 135F[/FONT]
[FONT=&amp]hold for X hours. When leaf looks right start Stem Dry. [/FONT]

[FONT=&amp]Notes:[/FONT]
[FONT=&amp] I need to start Yellowing at a higher temperature I think to reduce yellowing time.[/FONT]

 

[LeftyRighty]

Re: AmaxB- Flue Curing Tobacco at Home my Wins & Fails

would it help if leaf is over-ripe before starting the cure? By over-ripe, I mean some yellowing on the plant, noticiable color change, even lighter green on remainder of leaf.

I don't flue-cure yet. But, I have great success with my air-cure of Afr Red if I I let the leaf get fully ripe before priming.

 

[AmaxB]

Re: AmaxB- Flue Curing Tobacco at Home my Wins & Fails

The leaves I put in were Ripe LeftyRighty
I think I have been babying the yellowing phase to much working with low temperatures waiting for the leaf to yellow. Instead of making it happen.

 

[AmaxB]

Re: AmaxB- Flue Curing Tobacco at Home my Wins & Fails

I could have Titled this thread differently and should have
Flue Curing Tobacco at Home my Wins & Fails (it is not about me) Flue Curing Tobacco at Home Wins & Fails would have been better.
A little help Mr. Deluxe

 

[Chicken]

Re: AmaxB- Flue Curing Tobacco at Home my Wins & Fails

man that stuff is tanned very nicelly, [ what strain is that ? ]

looks like your machine kicked ass,

i believe some-one who is serious on doing what you did, could read no better thread than your build,.

to see exactlly how to make one for the garage, that works like one that professionally built would run thousands,

and i salute you for taking it to the next level.

..me myself, ill just stick to my heater, and crock-pot,{ old schooling it ]

 

[holyRYO]

Re: AmaxB- Flue Curing Tobacco at Home my Wins & Fails

The leaves I put in were Ripe LeftyRighty
I think I have been babying the yellowing phase to much working with low temperatures waiting for the leaf to yellow. Instead of making it happen.

My "armchair quarterback" view on the flue curing process, heat is only added during yellowing just to keep the humidity from getting too high and getting condensation. I have read in the old days they did not add heat during yellowing. More heat may risk setting the green and actually be fighting the yellowing . Only a suggestion, try hanging a control leaf outside your chamber. If the control leaf is progressing as quick as the chamber leaf, then it may not be a heat thing, or vice versa. I often wonder about the temp and humidity graphs, I would think they apply to commercial chambers that are curing tons, not pounds. For only two batches, you are doing great... keep up the good work... and thanks to all the flue curing trail blazers for sharing with us. For what its worth, my neighbor's father used to flue cure 300 acres worth of tobacco, she said it was more "touchy feely" than watching gauges, around the clock monitoring the progress, experience prevailed.

 

[DGBAMA]

Re: AmaxB- Flue Curing Tobacco at Home my Wins & Fails

Will be more detailed when I get on computer and not phone but I believe yellowing is the most important part and the general guidance temps are a bit high.

 

[DGBAMA]

After one batch run and a lot of reading here, my take on flue curing: Twisted a little for the home grower, not the commercial processing where it was developed.

Stages:
Yellowing
Wilting
Leaf Drying
Stem Drying

These criteria do not really differ from the natural process of waiting for leaves to partially yellow on stalk, then cutting and hanging and letting nature do the rest. The trick is the accelerated pace, a week or less instead of months.

Yellowing: occurrs naturally and is key to not having green leaf taste or needing excess time to age the leaf.

Wilting: removing excess moisture from the leaf before drying (prevents mold and is less damaging to the cell structure of the leaf than speed drying)

Leaf drying: Needs to be at a rate that does not effect the structure or solids content of the leaf. Too slow will mold, too fast will not allow natural aging enzymes in the leaf to do their job

Stem drying: Just what it says, and all about speeding up the process and minimizing risk of mold damaging the leaf. The high 165 deg temp also fixes color rapidly and retards any future natural aging of the leaf (great for a commercial application where a consistent and rapidly available product is desired but not the best for us little guys persuing the best leaf we can get).

In the temps between Leaf Drying and Stem drying; roughly 130-165, there is an enzyme process that converts starches in the leaves to sugar; Comparing tobacco to other fibers/grains often are converted to sugar it would appear that temps over 150 deg kill of the enzymes responsible for the conversion. Time in these temp ranges has a big effect on the finished flavor of the baccy. Temps over 160 kill off the aging/sugar producing enzymes and may even cause produced sugar to carmelize/darken the leaf. Killing off the aging enzymes at 165 deg is ideal for commercial because results are more consistent from curing until end product.


For the little guys like us:
Yellowing: keep it in a natural temp range for ideal coloring (95-100 deg) 105 from first batch observation borders on wilting which tends to fix color in the leaf. The accelerated process of flue curing is achieved not by more temperature but by maintaining the proper conditions 24 hrs per day.

Wilting: 105-125 and high humidity. We want the leaf to go limp and leathery and as much excess moisture removed as possible without actually drying anything

Leaf drying: 125-135. Basically until the leaf dries to low/medium case

Stem drying: 135-150. My first batch dried completely including stems in less than 36 hrs, stems brittle and leaf falling apart crumbly when touched.

My theory in not going all the way to 165 is the leaf when brought to order will still have natural aging enzymes available and will continue to get better with age instead of being stuck in the condition it was dried in; this is my deviation vs commercial temps where the goal is fast and consistent vs us needing to dry fast to conserve space yet want the fine wine “gets better with age”.

If I want to ramp up the sugar content or carmelize or fix the aging process I can bring leaf to high case, put in the chamber and ramp to 165 deg or more to kill/darken it. If I want it sweeter I can hold the 145-150 temp range longer.

This is how I will approach my second run in the flue cure chamber. Thanks to everyone documenting their experiences in kilning, flue curing, toasting, etc and your impressions of the results. This post is a combonation of reading all of that and my own observations of leaf curing of my own.

Just my take and look forward to completing my second more educated run of the flue cure chamber.

Sorry for getting long winded.

 

[deluxestogie]

The Oxidase enzyme (the primary "aging" enzyme) is denatured at about 149ºF. A slower enzyme, a peroxidase, is not denatured until 189-191ºF. This peroxidase enzyme, which usually persists after flue-curing, does allow flue-cured leaf to age gracefully, and likely accounts for the subtle changes to flue-cured leaf that is subsequently kilned for a month, or is allowed to naturally age for a year.

Bob

 

[DGBAMA]

Thanks Bob. Will adjust my final dry temp down a few degrees. Want to keep the leaf working FOR me NOT against me.

 

[AmaxB]

Yeah Man Woohaa
HolyRYO I agree from what I am experiencing it is as much about touchy - feely as it is gauges
DG your on target my second batch I had prolonged yellowing but wilt and dry were done in less time than the standard graph dictates.

This is exactly why I started this thread. If we all pitch in not to get a pat on the back but to honestly share information and opinion we can each and all gain a deeper understanding and grow.

There is little to no real information for a small time home grower in reference to flue curing it is simple yet difficult.
I have a ton of PDFs on the subject a couple are of different opinion those remaining are near carbon copies of the one before.

I hope for this thread to be helpful to all...

As most who are involved here on the forum know I have sunk some money into my Flue Curing Chamber made it a little bit on the techy side.
When I can focus or decide how to piece the information together I will create an informative thread and post all at one time.
For now the subject of Flue Curing I want to share in regard to digital control verses Dry / Wet Bulb.
In the time I have been running I am seeing one big consistency beginning a cure run Digital and Dry Bulb temperature within the chamber are 1 degree or so apart.
As the run progresses this changes to about 10 degrees the Dry Bulb being the lesser. If I'm to believe the Dry Bulb I was yellowing at 90 to 92 degrees through the first few days.
While temperature within the tobacco was a degree or two higher and that of the chamber was 100F or so.
My Digital Humidity is spot on with my Wet Bulb. The Digital Control for temperature I believe to be accurate but the sensor to be in the wrong location.

For the Third Batch I am going to use the Dry / Wet bulb only. I know I can Yellow in less time than I am.

 

[AmaxB]

That is good information Bob I agree with DG..reference post #9
Thank You for the Title Adjustment my friend.

 

[DGBAMA]

You said a mouthful. I think the trick to yellowing (which occurs naturally) wizooming in on the ideal conditions for this to occur and maintaining those conditions 24/7. Not trying to speed things up. Like a good corn mash. LoI

 

[AmaxB]

Lol I have a patch full of ripe tobacco and am feeling the pressure. 70 to 80 hours is to long while leaf is near 100% yellow still have the green veins and leaf starts to develop browning areas.
Started my wilt this morning am at Dry Bulb 118F now and Wet Bulb 100F & 50% of the green vein has gone I will leave it alone now until early in the morning. Plan to finish wilt around 2 PM tomorrow
and start drying stems if the leaf looks OK if not I'll give more time.

 

[DGBAMA]

my second run started this afternoon. I started fairly agressively. within a few hours I had it stabilized at 96-101 temp and 98% humidity. 105 deg i think is pushing wilt. We will see. Old pile curing (for yellowing) suggests leaf in the middle of the pile yellows faster (more consistent temps/humidity) hence the re-piling daily) I see no reason to take a day to ramp up to yellowing temp, as long as conditions are stable. I went from ambient to 100 deg as fast as I thought possible and not have "hot spots" within the chamber.

 

[DGBAMA]

natural ideal yellowing conditions only occurr for a few hours a day even for people with the best possible weather. Accelerated curing is truly a tortise/hare situation. If ideal conditions are available 4 hours a day and the process takes 6 days, then maintaining the same conditions 24/7 means the process can be done in a single day...............you get the idea. Slow and Steady.

 

[skychaser]

Re: AmaxB- Flue Curing Tobacco at Home my Wins & Fails

But, I have great success with my air-cure of Afr Red if I I let the leaf get fully ripe before priming.

Me too. I don't consider it ripe until it has changed to a lighter green and started to yellow a little on the plant. That's when I start priming mine. I think your coloring will go a little easier with the African Red if you leave it on the plant another week.

 

[AmaxB]

Tobacco leaves reach full maturity a few days before ripening. Mature leaves exhibit a slight
yellowing and puckering between veins and break off the stalk easier than immature leaves. Fully
mature leaves cure easily, and the quality, color and weight are usually good. The best quality cures
occur when the tobacco is allowed to mature in the field. The stages of maturity are: premature,
mature, ripe and overripe. Tobacco harvested in the ripe stage may be cured to give better color,
quality and weight than tobacco harvested in the overripe stage. Overripe tobacco does not color
as well as tobacco harvested and cured at proper maturation. You should let the tobacco
mature but not become too ripe before removing leaves from the stalk.


Cured leaf quality depends on having uniformly mature leaves. Quality cured leaf is nearly
impossible to achieve if several leaf stages of maturity are in the same cure. Tobacco in any one stage
of maturity (except premature) can be successfully cured if attention is focused on that one maturity
group. Premature tobacco is nearly impossible to cure under any condition.


During the yellowing and leaf-drying phases, humidity control is essential to success. Keep in
mind that the relative humidity drops as the curing temperature advances.
Advancing the dry-bulb temperature and wet-bulb temperature in relation to each other is a critical
feature of curing. When starting a cure, close air venting before turning on the heater. Turn
the heater on and gradually raise the temperature to the yellowing range 90F to 105F. Do not raise the
temperature more than 5F at any one time. Allow about 30 minutes between temperature rises to
provide time for the curing air to become humid.

My leaf is Ripe / I am not mixing maturity groups / I am not mixing varieties
I believe Time To Yellow is linked directly to the Temperature - Humidity and Maturity combination as the Primary consideration with Sub-Considerations - Weather, Soil, Fertilizer, Variety, and Stalk Position.

My next run (Batch 4) I will not be so concerned for the well being of the tobacco but more focused on the effect versus time. I'll use three means of control the digital humidity for venting, Heat applied temperature,
and Dry / Wet Bulb for guidance.
Batch 3 should be completed tomorrow.

 

[AmaxB]

Hind Sight is better than Fore Sight
Maybe 10 leaves at a time to yellow would be the way to go, could reduce time & loss to figure things out 30 hours as opposed to a week

 

[ne3go]

I believe Time To Yellow is linked directly to the Temperature - Humidity and Maturity combination as the Primary consideration with Sub-Considerations - Weather, Soil, Fertilizer, Variety, and Stalk Position.

Very nice organized thought. For the Primary considerations, there are best "settings". What about the Sub-Considerations?