practice run on kiln fermenting Canadian Virginia whole leaf tobacco

[SmokeStack]

Hello,

This is my first post and this forum seems to be the most appropriate for it. About a month ago I purchased 5 lbs of Canadian Virginia whole leaf tobacco to use in a practice run for fermenting tobacco in my first and newly built kiln. It now has been 3 weeks in the kiln at about 115 - 125 F. At first I had troubles as the tobacco kept drying to a crisp despite having paid big bucks for a cigar humidifcation system - it could not keep up with the humidifying at these elevated temperatures. Anyway, I drenched the tobacco with distilled water and that seemed to help. I did not worry about mold because I heard that mold will not grow above 120 F - so I kept the temperature around 122 F.

I read that the tobacco takes 4 to 6 weeks to kiln ferment. Also, I read that I should rotate the tobacco in the kiln weekly and I should notice at some point the smell of ammonia given off during the fermentation. I did not smell any ammonia so far; in fact, the bright yellow tobacco with which I started turned a dark brown. I sampled the brown tobacco in a pipe and it was not at all harsh like it was before I placed it in a kiln. (I saved a sample of the original Canadian Virginia for comparison.) I am not sure whether I should continue leaving it in the kiln any longer - I am afraid it may decompose. Also, I did not smell any ammonia at any point so I am not sure what happened.

Is it to early to remove from the kiln (after only 3 weeks)?

Would leaving it in the kiln further help or do I run the risk of ruining the tobacco?

Is it normal for a bright yellow-colored Canadian Virginia to turn dark brown?

And lastly, will fermentation make the tobacco sweeter or will the sugar content decrease?

Thanks for taking the time to read this lengthy post; I would greatly appreciate your input.

-Marco

 

[deluxestogie]

Welcome to FTT. One answer to the humidity problem in the kiln is to use a Crockpot as a heat source. You can add water to it every two to four days. Also, a half-cup of rock salt in the kiln will trend the humidity toward 75%.

What happens in the leaf during aging or kiln curing is primarily caused by two enzymes that remain active in air-cured, dead leaf. The most active is an oxidase that is denatured at about 149ºF. A less active peroxidase is stable up to about 191ºF, and is likely the only one remaining after typical flue-curing. Most of the excess nicotine and albuminous proteins were taken care of during the flue-cure process, hence no ammonia smell (which is derived from the oxidation of those proteins and some alkaloids.)

I don't know what the carbs do in the kiln. I can say, though, that thick, rank tip leaf kilns into a nearly black and very sweet leaf.

In the absence of active enzymes, heat and near-saturation moisture will darken leaf until it turns black. This is how Black Cavendish is made.

If the humidity in the kiln can be kept below 80% RH, an increased duration of kilning doesn't seem to adversely affect the leaf in flavor or color. (Just today I brought some Izmir Ozbas leaf out after 5 weeks at ~131ºF and ~75% RH. It is fragrant and a deep golden color, while some other varieties under the same conditions at the same time came out maduro to oscuro.)

In general, I leave all of my leaf @~125ºF for 4 weeks regardless. All improve dramatically in a week of resting after it comes out.

Bob

EDIT: the rock salt, of course, goes into a separate cup, not in the Crockpot.

 

[SmokeStack]

If I have interpreted you correctly, I may have been unsuccessful in procuring the fermentation process. By this I mean that there are two possible mechanisms that may have yielded the dark brown tobacco: either the kiln fermentation process did work (via enzymes) or I have made Black Cavendish. I am considering ordering another batch of flue-cured Canadian Virginia and repeating this experiment. I had trouble with the tobacco drying to a crisp (especially the leaves packed on the bottom closest to the heating pad) - that's the reason why I drenched the tobacco with distilled water using a spray bottle. I didn't know that heated-saturated leaf would lead to making Black Cavendish. I don't think a crockpot would even fit into my kiln (built according to seedman.com) without some reconstructing - the kiln is relatively small. I am unsure at this point. I guess I will take your suggestion and give the crockpot/rock salt method a try. Using this method, maybe I should see if I can maintain the proper temperature and RH before placing the tobacco into the kiln. I'm afraid of blowing another $100 worth of whole leaf. Unfortunately, that's what experimenting is all about - at least I know how to make Black Cavendish. Thanks again for your reply.

-Marco

 

[deluxestogie]

Marco,
With a very small kiln, you can probably get the job done with a little 2 qt. Crockpot set on the Lo setting. A thought about experimental leaf: BigBonner, a member of this forum, has some wonderful burley that would be a better test than the flue-cured leaf. Send a PM to BigBonner to learn the price per pound. Unlike your likely flue-cured source, BB raises his own tobacco and air-cures it on his tobacco farm in Kentucky. So the price is right, and the quality is excellent. (I just finished a burley puro cigar of BB's leaf not 30 minutes ago.) The mid-plant leaf is fairly bright, while the upper leaf (red) is darker and a bit fuller in body. His 2011 crop would be a good test for the kiln, while his 2010 leaf (1-1/2 years hanging) is friendlier unkilned, and even better after the kiln.

Bob

 

[Daniel]

I also notice that tobacco does not stay evenly moist in a kiln. My first kiln I simply kept stirring it up. lower leaves woudl dry while upper leaves would be to moist. I heat my current kiln with heat lamps and am going to install a heat sheild (piece of metal. over the lamps between the tobacco and the heat this year. hopefully this will allow the heat to spread out more evenly on the leaf and not radiate directly at the lower leaves. I solved the problem last year by simply shredding all my tobacco and packing it in plastic bags. It still aged just fine.

 

[Jitterbugdude]

I also notice that tobacco does not stay evenly moist in a kiln...... lower leaves woudl dry while upper leaves would be to moist..

That is why I use a warm mist humidifier in mine. As it creates steam it blows it upwards creating enough air movement to keep everything evenly mixed ( humidity and temp wise).

Randy B,

 

[DrBob]

Marco
Curing time varies a lot. The age of the leaf is the first variable, the longer the leaf has been stored the less tme the leaf will need to cure. The purpose of curing is speeding up the aging process. 3 year old burley barely needs any curing at all, but 7 days at 120/70% does wonders for it. 1 year old burley needs about 21 days. 3 month old burley needs about 28 days. Air cured virginia takes a little longer than burly about 25% more time

My curing chamber is a 6' tall upright freezer modified for curing and heated with a 6 qt.crockpot. My water consumption is about 3 quarts/day.
A good thermostat is a necessity.
Bob

 

[LeftyRighty]

The leaf most likely darkened, too dark, because you wetted it directly with water, it just got too wet.
I've learned the hard way that spraying the leaf directly with water seems to always produce poor results.
Water droplets will leave spots on the leaf, and will quickly mold on those spots if temps are below 110 degrees for any length of time. Never spray with water to bring into case, and then try to store the leaf. I always use a high-humidity envirorment to bring or keep leaf into case, either place in an ambient (wet weather) area, or saturate the air in the kiln-fermenter.

Any leaf will darken slightly in the fermenter, whether at 70% or 80/90% relative humidity. My experience with the kiln-fermenter, crockpot-style, has been that water alone in the crockpot will produce near 70% RH, but the leaf will seem dry or at best low-case. Bringing the RH up into the 80's or 90+% inside the kiln will bring the leaf into medium or high case, but never has it gotten too wet or saturated. And, at this higher humidity, the leaf does not darken significantly more than at 70% RH.

My kiln is poorly insulated, and leaks air, so I've had to go to some extremes to keep the humidity up. My favorite trick now is to hang a folded, wet terrycloth towel on one wall of the kiln. I saturate the towel, wring it out to just shy of dripping wet, and hang it the kiln. This brings the RH to the 80/90's, and at the 115-130 temp range, and is good for a few days before the RH drops to near 70. I've never had condensation form inside the kiln at this temperature range, and the leaf has never gone beyond medium/high case.

I've use this hanging-wet-towel method to bring dry leaf into case to process (de-rib, shred, whatever). Never had it get too wet. And, I don't think that running the RH through the range of 70 to 90's has a detrimental effect on the fermentation process. Don't know if anyone else has experience with high-humidity fermentation - I wouldn't mind to get some feedback on this.

 

[SmokeStack]

Thanks all for your suggestions - they are well appreciated. Daniel brought up an clever and simple solution to maintaining tobacco leaves with a constant water content. Once the tobacco has acquired the proper moisture level, he placed the (shredded) leaves in a sealed plastic bag. I thought that this was an excellent idea. Since the moisture is trapped in the bag, there would be no need to hassle with any humidification system. Since I am making pipe tobacco, I would not shred the tobacco - rather I would place the whole leaf tobacco in the bag (well sealed). Does this method sound like a viable option?

 

[LeftyRighty]

I agree, Daniel's suggestion is a good one, to place in a plastic bag, in the kiln, to keep uniform moisture. But don't seal the bag, just close it or fold the open end over. If you seal it, the expanding air from the heat will pop it open anyway. I've used FmGrowit's Vapor Proof Bags (see http://www.fairtradetobacco.com/showthread.php?418-Vapor-Proof-Bags), with the end folded over, and it works well. No plastic odor, like zip-lock bags.

 

[deluxestogie]

Another issue with a sealed bag that contains leaf in perfect case is that the RH will drop inside the closed space as the temp increases. (It makes my brain hurt to try and figure out what that does to the H2O available for chemical reactions within the leaf lamina.) And this will vary from bag to bag, depending on its contents. I use open plastic bags (freezer 1 qt. Ziplocks) with the open end folded over the outside. My initial reason was to easily separate multiple varieties within my small kiln. Open bags means having to regulate the humidity within the kiln.

Early on, I shredded my cured leaf before it went into the kiln. I later regretted this, as my cigar-rolling skill improved. In the process, I discovered that some wonderful cigars don't necessarily have to have the same old flavor of factory cigars.

Bob

 

[LeftyRighty]

You may also want the bag open, so it may burp out any deleterious compounds. About once or twice a week, I'd burp mine, kinda give it CPR, to expel nasty gases and draw some fresh air into the bag. No scientific basis for this, just seemed logical.
Also, the Vapor Proof Bags I'm using area bit bigger than a ziplock.

 

[Daniel]

I use Large freezer bags, No odor transfer. U-line might also be a good source for large bags but select carefully. It also requires a large order. If people wanted to get together on a single order that I could then split up and mail to everyone I am willing to do it. I have done things like that a lot in the past. Only problem is I will have to figure out a min number of bags per person or it becomes to much packing and labeling.
I am thinking something like these.
http://www.uline.com/Product/Detail/S-12256/Poly-Bags-Reclosable/12-x-18-4-Mil-Reclosable-Bags
12X18 inches reclosable 4 mill thick plastic (they also come in 6 mil and 8 mil for higher prices. these work out to be about 25 ish cents per bag not including shipping and then postage to the end user.

These http://www.uline.com/Product/Detail/S-14390/Poly-Bags-Reclosable/30-x-30-4-Mil-Reclosable-Bags
are 30X30 inches also 4 mil but cost about $1.52 each.

Warning, Shipping on these items can be high. the first example weighs 27 lbs per carton. I usually figure at least a dollar a lb for shipping. For shipping to double the cost of an order is not unheard of from Uline.

 

[deluxestogie]

Be sure to compare the plastic bag prices with US Plastic: http://www.usplastic.com/catalog/default.aspx?catid=684&parentcatid=451. I've found significant differences on some bags (much cheaper at US Plastic).

Bob

 

[Jitterbugdude]

Daniel brought up an clever and simple solution to maintaining tobacco leaves with a constant water content. Once the tobacco has acquired the proper moisture level, he placed the (shredded) leaves in a sealed plastic bag.

I did something similar last year. After hanging my tobacco in my kiln I had a lot of unused floor space available. I packed about a dozen mason jars with tobacco ( some whole leaf, some shredded) in medium case and put them (with lids) in the kiln. I opened the lids once a day for a few seconds for the tobacco to breathe. Worked out fine.

 

[SmokeStack]

I am thinking about ordering heavy duty bags from www.uline.com. I can get a carton of 100 bags that are 18 X 24" and 8 mil for $76 (http://www.uline.com/Product/Detail/S-7004/Poly-Bags-Flat-Open/18-x-24-8-Mil-Poly-Bags). One carton weighs 26 lbs. Since they are made of "100% virgin polyethylene film," would these bags survive in the kiln temperatures?

 

[deluxestogie]

All that I could find is the hot fill temperature of bottles:
HDPE (high density polyethylene) 145 F
LDPE (low density polyethylene) 120 F

I have had ordinary sandwich bags spend a month in the kiln at ~130ºF. They come out pretty flaccid, but intact, and they regain their normal feel at room temp. The heavier freezer bags seem to have no discernible change with kilning. So I think you're OK.

Bob

 

[Jitterbugdude]

I do not use plastic bags in my kiln because I try to limit my intake of plasticizers and dioxin. Believe it or not I think small amounts of tobacco are healthy for you and I do not want to add anything that might adulterate the pure tobacco that I am growing. We are inundated everyday with toxic chemicals, no need to add more if you can help it.

Randy B

 

[DrBob]

I have never used plastic bags in the kiln either. My chamber is relatively air tight but I have a controlled amount of ventilation to let the fumes out. Meybe 4 air changes per day. I believe the tobacco has to breathe a little to vent off the fumes.

Works for me, Has worked for me a long time now. Aint changing my method.

 

[Daniel]

I used large freezer bags last year. No damage to the bag unless I got it to close to my heat lamps. But they tolerated 120 degrees just fine. Jitterbug does have a valid point, above a certain temperature. Bob listed 120 degrees as the lowest temperature for polyethylene so I would not go above that for any polyethylene unless I knew otherwise.

We emptied our bags into a tub once a week. misted it to keep moisture levels up. let it breath and then repacked it and replaced it in the kiln. Moisture still wants to migrate up leaving each bag dryer on the bottom and more moist at the top. But it reduced the time requires to keep the tobacco stirred from twice a day to once a week. Adding a fan to circulate air and moisture will also help keep the bottom leaf moist in a kiln.

I did not find the tobacco required any more breathing than our once a week stirring. That of course was some pretty extreme breathing.

I have seen several times people mention concern for "Off Gassing" in one form or another. I realize this is mostly a concern that "If" there is in fact anything to off gas. I have not found this to be true and even if it is I do not assume I want those gases to escape anyway. Being there is not evidence that there is a negative effect. I would be most concerned about the issue of oxygen. Evidently a weekly pouring out and stirring up of the tobacco provides ample oxygen. The process may work faster with more frequent stirring also. I may be getting a couple of days of fermenting with each stir and then starving the atmosphere of oxygen also. All I know is it worked and it worked much better than hanging tobacco in hands.