Tobacco Fermentation / Curing Chamber for Cigars




Tobacco is an age old, yet amazing plant, which has become increasingly popular among hobbyist in recent times!

Perhaps it is a distraction from daily stresses and allows an escape to simpler times. For some, growing tobacco is an absolute obsession...and its easy to see why! Tobacco starts from shockingly tiny seeds and grows a million fold into a 6-7 foot monster in just about 5 months. You too can join the ranks of tobacco plant enthusiasts and with some luck and planning, your efforts may be rewarded with a homegrown cigar!

Growing and harvesting is a perquisite to fermentation covered in other guides, available here . This instructable picks up after you have air cured your green leafy bounty and is one possible way to simulate the needed conditions for fermentation at home. **Tobacco sowing season is NOW! March-June,get started TODAY!**

This project was created last year (2008 harvest) to provide address a common question in the tobacco growing hobby, discussing the critical points of curing tobacco. Also provided is an example of how one may be able to affordably recreate the conditions needed for tobacco fermentation. No oil heaters required!

Step 1: Before We Start...

Before starting here's a small note of discretion: Typically tobacco growing hobbyist raise and cure these plants for the pure enjoyment of taking care of this fast growing monster! There is great potential for a wonderfully cured crop at the end of the growing season, however this hobby shouldn't be taken as a way to save on your tobacco spending money as there is a lot of time and labor invested with a lot of potential for crop failure due many factors: both while growing then the potential of mold during the curing process!

On the plus side: Home grown tobacco contains far less chemicals and no additives when compared to the stuff the tobacco industry produces. Buuut, it is still good to note the same surgeon general warning that "smoking is bad for your health", etc.

That being said, lets get started! Whoo-hoo!

Step 2: Supplies

What you will need:

-Air cured Tobacco leaves, Seeds with growing instructions are available here :
Havana tobacco seeds are good for making cigars, particularity cigar wrappers because of the broad leaves, flavor and smooth appearances once cured. A good recommended fill blend for a home grown cigar is 30% Havana leaf and 70% Virginia leaf with a Havana wrapper.

-Cheap, light weight foam cooler: if you ever wondered what to do with that leaky foam it is!
-Corded clamp light reflector light fixture, (avail. at home depot, clamp assembly is not needed)
-30W light bulb (heat source)
-Aluminum foil
-Clean paper towels
-Plastic bag
-Sterilized spray bottle (use bleach solution to clean, rinse and dry thoroughly)
-Distilled water

Step 3: The Curing Process

Curing is a 3 part process:

1) Drying (color curing): to take out majority of the moisture.

The best way to do this is pictured on step 1, hang leaves to dry and let nature take its course: Gather your harvested green leaves, use a zip tie at the stems and bundle into 1-4 leaf bunches, (be sure to allow air between the leaves, if the leaves stick together, they will mold). This process takes about 3-4 weeks.

2) Fermentation: Sweating out ammonia, and a few other complicated chemical processes. Fermentation also stabilizes the leaf so that it doesn't decompose further in storage.

Fermentation is the trickiest part, and is what this instructable is intended to outline. Fermentation is the limiting factor for hobbyist!

3) Finally aging which we are all familiar with, which includes factory storage and storage in a humidor.

There are several ways to ferment at home. This is a cheap and accessible possibility to achieve the conditions required for fermentation.

I personally didn't run into any problems, but this set up is risky and definitely not UL rated . I do not recommend that anyone follow this procedure, please use discretion with the project. I did have a hard time sleeping at night with the chamber light bulb on. The light was plugged into a ground fault interrupter outlet so that if it overloaded, I would have a small means of safety at very least. And I always unplugged the light when leaving the house. Unplugging would have some impact on the fermentation process depending on the length of interruption, but better to unplug than to not have a house when you get back.

Step 4: Fermentation and the DIY Fermenter

Cigar tobacco producers ferment tobacco naturally by creating huge piles of air cured leaves. Essentially creating a compost heap where the internal temperature is carefully monitored along with the humidity levels.

Basic idea of the home chamber is to simulate the internal temperatures of a tobacco pile as seen at tobacco production facilities. Basically you need heat (approx 120 degrees) and humidity of about 75%, if this can be sustained for approx 4-6 weeks, fermentation will be complete.

In this fermenter, these conditions are achieved by a light bulb heat source, directed by a reflector dish towards the pile of air cured tobacco under it.

Paper towels misted and saturated with distilled water is placed on top of the cured tobacco hands with some plastic wrap over it to hold in the moisture, I do a good deal of misting with distilled water about twice a day.

Step 5: Aromatic Stages...

During the fermentation, there are several aromatic stages:

-Week 1-2 smells like wet grass.
-Week 3 smells very strongly like raisins.
-Week 4 the tobacco chamber should have the sweet smell of a walk in humidor. The tobacco color should also change to a much darker hue of brown.

-An extra week or two of fermentation beyond the 4th week wouldn't hurt.

Step 6: Q & A

The following is a helpful "Q and A" following this project. Questions by inquiring hobbist , answers by me, (Surf Monkey Coconut)!.

Q: Cool setup- never seen it done like that before. Any concerns of the foam smell transferring to the tobacco?

A: I know the foam smell you are talking about, Its an undeniable chemically semi-sweet smell...I've experienced it in the past when using a hot wire to cut foam doubt very toxic!

In my past experience as well as experiences in this fermenter, insulating foam is for the most part stable and inert; It won't off-gas unless it is melting. In terms of my fermentation chamber, there is no problems with overheating or melting...yet!

There are several websites dealing with curing chambers and the standard home made type is made of foam wall insulation and an oil heater. All I can think of is fire hazard!! Dedicated home growers use old refrigerators with a heat source.

I did see a fermenter made of ply-wood, and i can tell ya, that one would most definitely off gas formaldehyde and other such chemicals found in the adhesives.

Q: So you haven't noticed any sort of ammonia smell coming from the tobacco?

A: I really haven't! Although I may not be identifying the ammonia as released from tobacco leaves correctly.

When I think of ammonia, I think of a sharp biting smell, the chemical smell from either a bottle of windex or urine..(I once had mice as pets, which had that horrible smell...)

When I was researching tobacco fermentation I pictured those fermentation barns in central America to be awful, perhaps like walking into a tear gas chamber...Taking this into consideration I have my fermentation cooler in an unused bathroom which has the ceiling vent on a timer (it turns on for 10 mins every hour). But really, there are no unpleasant smells to be vented. I even leave the bathroom door open.

I did miss a stage in my above aromatic observations...between the wet grass and raisin stage there was a strong cereal toasted corn flakes, which probably lasted for the entire 2nd week. But to me, all of these smells were delicious!! I wanted to just bury my nose in the leaves during the raisin stage, but for purposes sterility, i resisted!

Q: I wouldn't imagine such a small batch would give off an overwhelming smell of ammonia.

A: Very true! This is just 3 hands of tobacco and it does have quite the aroma associated with it! A factory barn with hundreds of thousands of hands fermenting, well...that would be a whole different level of aroma.

Q: Surf Monkey Coconut, your insurance agent called me looking for you. He said he needs to do a random check inside your house but you keep on ignoring his calls.....

Anyway that is soo cool. Also how do you keep the humidity. I realize the leaves are moist at first but after the moisture evaporates do you have to have any humidification device in there?

A: yeah, as you can imagine, lamp is very similar to an oven, where the dry heat generated constantly takes away the humidity. I don't really monitor the humidity too much, I just give it 15-20 distilled water misting on and between the hands about 2-3 times a day, just to keep the leaves semi-moist.

On one end you want to keep the leaves from getting soggy to avoid mold and decay, and at the other end you want to keep the leaves from becoming dry and brittle without moisture, fermentation not will occur.

Keeping it right in the middle keeping the leaves are warm and supple seems to be the goal..The layer of wet napkins and saran wrap helps a little to hold in moisture between mistings. Also, in the images above you can see the vent holes I cut in the top and bottom of the cooler...I have since plugged them up to hold in the humidity...there was too much ventilation going on.

That being said it is taxing to spray the leaves so often. In the next batch I think I will see if placing the leaves in a large plastic bag will work better.

The essential pieces for fermentation is 120 degree heat and humidity. The fermentation cooler I built is, in my humble opinion, is a very cheap and affordable chamber for the home enthusiast.

since taking the pics, I have modified and refined the design making it even simpler...ive plugged the holes, and took out the aluminum foil, and put the second batch of leaves in a large plastic bag with a twist tie on the top to better hold in the moisture.

Really its just a foam cooler with a $5 light from Home Depot now...

Oct. 26, 2011 UPDATE:

In the final version of this fermenter, a (I simply used a cooler with no air holes, just one hole punched at the top for the light fixture). I've found this setup makes the temperature get much too high, (due to the excellent insulation of the cooler, the cooler gets cumulatively hotter and hotter). To counteract this situation, I have replace the bulb with a lower wattage, 32 watt and put the light on a timer, set to go on for 30 mins then off for 45. This seems to be the right amount of heat!



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    55 Discussions


    Question 2 months ago

    If pile of tobacco is big enough, and insulation is as good as it is inside the foam cooler, wouldn't there be enough heat generated by fermentation process so that no external heat will be required? At which temperature fermentation stops? Isn't it possible to sterilize the pile of tobacco and stop all the fermentation by having temperature too high?

    I am thinking about trying this year for the first time.


    2 years ago

    Did this ever work to produce good cigars surf monkey ? Im going to do the same thing with an iquana light i have and a plastic tub with a lid ... I also might start my tobacco plants inside during jan ... Thoughts ? Btw i subbed you on youtube

    1 reply

    Reply 11 months ago

    Start the tobacco seedlings no sooner than 4 weeks before the spring night time temps are 50 degrees or so. The grow fast so don't start them too early, time it for the optimum outdoor transplant date.


    11 months ago on Step 6

    Instead of a timer you could also use an eight dollar dimmer cord found at any hardware store, it will adjust the power and heat output of any bulb.


    2 years ago

    Hi - What are your thoughts on smoking unfermented tobacco. I have grown some and do not want to ferment it. It is cured/air dried in a carport. Thanks


    3 years ago

    Hi guys. First time grower. Just wanted to see how it's done. Does my curing chamber look like it will work? It's half a keg with a bin lid and a light globe for heat. Was going to make a wooden box but this was easier as I had the bits.


    7 years ago on Step 5

    when air curing has happened with my plants there are vast diffrents in colour between the diffrent leafs some are dark brown - light brown but some are a very dark green.. they are cured they just seem to hold there colour..? mayb to much nitrogen locked in the leaf... what do you think

    8 replies
    Surf Monkey Coconutandybuda

    Reply 7 years ago on Step 5

    sounds like the uneven curing is due to inconsistent humidity and too dry of an environment. If parts of the leaf remain green, it has dried too fast. Did you dry indoors? This is typically the culprit. The best time of year to dry outdoors is during the harvest season, end of Summer, before the first frost, humidity is typically perfect in most areas of the USA. Simply hang in a sheltered area and let nature take its course.

    andybudaSurf Monkey Coconut

    Reply 7 years ago on Step 5

    im in manchester uk.. i have tried drying in about 4 diffrent places now over 2 years .. i dried that lot in the loft so there was temp fluctuation. and all so i listened to my mums idea of putting it between news paper which was silly thing to do, it stuck to the sheets of paper and when mouldy! proberly down to the paper.. the best way i found was hung up in a garrage. it was cold and had good air flow. i will try outside next year just abit worrie about things eatting them .. the slugs around here seem to have a nicotine addiction.
    this pic is just a couple of late bloomers that iv put in a pot outside if you notice on the dried leaf there is type of mould when cured outside have you had this proble befor or has this happened because its still attached to the plant?
    has not been a good year for growing this year but the other plants were about 5ft with broard leafs what was left after the slugs


    Reply 7 years ago on Introduction

    i hope this works because all my tobacco is in there.. iv got a brewing heat pad about 30 watts put a storage box on top will 2 lt of water. some plastic corks to keep the purple basket out of the water - filled the purple basket with the tobacco and put quite a thick bit of plastic over the top the plastic has been stretched and taped in place.. it has all been cleaned because this sort of condition breeds mold.


    Reply 7 years ago on Step 5

    this is a couple of hours later.. its a little sweaty box now


    Reply 7 years ago on Introduction

    this methored did not work the tobacco turned to compost in a few weeks.. to much humidity.. the way i would change it is having the inside tray highter and only puting a cloth over the top so air can escape.. i only put a small hole in the top and this was not enough.

    Hey thanks for all these follow up posts and pictures! I didn't realize you had all these messages! Good job documenting your work! Yes I agree that there was too much moisture. The biggest difference is that the plastic box did too good of a job sealing in the moisture, and perhaps there was too much to begin with. Also without an insulator, there would be a lot of heat loss, you would need higher temps than a psudo greenhouse.

    The cooler method traps in heat, but because the seals are not air tight there seems to be a lot of air exchange going on. In the cooler situation, I am fighting to keep things moist your case it looked like it was the opposite effect! It was a good shot at it though! And it sounds like you will be able to modify your system for next year!

    Just one note! From your pictures, your plants were very immature, their growth stunted mostly due to the small pot size. Remember these are monstrous plants that are supposed to reach 7' tall, if you can provide a minimum 5 gallon pot, lots of full direct sun and water, your plants will flourish! You will also have healthier, more mature/thicker leaves that will respond better to air curing and fermentation...a little more meat to chew so-to-speak.

    the pic was just of some plants that had mold growth on them.

    i plant them in the ground so i achieve maximum height.

    only grown one plant this year. and still have some tobacco from afew years ago.

    i think il try the box with water in and a towel on top after iv dry the tobacco this year.. only using a heat pad.


    Reply 7 years ago on Introduction

    Built a box frame 2'6" sq. x3' high lined with 1 1/2" styrofoam 3 100w heaters in bottom controlled by cookerstat,fed in moist air from a humidifier.Humidity 80% temp 120/130.Cured leaf for 4 weeks. smokes well,mild,smells a bit like cigar.


    3 years ago on Introduction

    Im from west Wales in the UK. To cure my tobacco i air dry it in my shed. If I think the tobacco is drying to quickly I give it a light misting with the distilled water. Once the tobacco is dry to my liking or touch. I then start fermentation I do this in a burco boiler. I have it running on a low heat for up to two hours checking on the tobacco and turning it throughout the process. Once this is done I remove it from its leaf stems. The tobacco is best if the leaf stems are still slightly most when you remove from the stems. I never over fill the boiler with water or leaves. This will always depend on how much you grow and how big your boiler is. Mine is 40ltr any old water boiler come tea earn will do. You will need to make a platform inside the boiler to keep the leaves out of the water. always use distilled water in the boiler.

    1 reply

    how long you been using that method andrew,how is the smoke,just new to this first year growing tobacco,any chance you could post more detail of youre method,is it the steam that ferments the tobacco ,how long do you do this for, you said you have it running on a low heat for two hours,how many days do you do this for


    8 years ago on Step 6

    To me the way you have this all set up is nothing more then a fire hazzard. Now I do think I have a better way to accomplish this process. Which I am getting from my experience with raising tropical reptiles and snakes. It would be slightly more expensive but the concept is entirely the same.

    What you would need is a fish take with a lid. The lid can be a screen lid for if you think that you need to remove some of the ventalation from the chamber. You simply need to take tin foil or plastic wrap and wrap the lid.

    Now for say jackson chameleons who require just about the same conditions as you are describing. They do like it slightly cooler but they do love the extra humidity. So what I would do instead of wrapping the screened in lid is I would simply add a second clamp lamp and or maybe a strip floresent light with a day light bulb. This would take away some of the extra spaces allowing the humidity to escape. Also instead of a 30 watt bulb I would use atleast a 90-150 watt incadecent bulb.

    This give you the heat source you would need to keep it around the temps you are talking about. Then for the moisture you just need to either set up the tank with either a water dish on one side. When the water evaporates out you simply need to add more water to this dish and you are all set.

    I have not tried this my self yet since I recently decided to start growing my own but I will be taking my knowledge of keeping tropical reptiles alive and mixing it with the process you are talking about. Also I want to note that if you are noticing that your cured leaves are getting slightly to dry simply make sure that you place the light over the water and not over the leaves. This way you are not forcing them to dry out but instead giving them the humidy and heat from the water. It will make the water evaporate alot faster but to me this sounds like it would be a much safer and reliable solution.

    If any one feels like trying my method out please feel free to contact me and let me know if it works while I wait for my first plants to grow.

    1 reply

    Thanks for your comment Tim The-Tool-Man Taylor,

    There are many ways to make an omelet, you are free to create your own instructable if you experience any success, but "more power" doesn't always equate to a better product. There are just a few points in your redesign that are counterproductive to the point of this instructable which is "affordability". If you want to invest good money in this, there are many more expensive DIY projects that utilize expensive materials: repurposed refrigerators, foam insulation fermentation closets, and even a "UL rated" solution suggested in the below comments using an egg incubator for fermentation.

    Regarding this project being a potential fire hazard: YES! It is best done outdoors with an outlet fitted with a GFI. However it is a measured risk with the low wattage (30w) bulb and careful monitoring of temperatures, (much lower than combustion).

    Remember we are trying to mimic NATURAL fermentation processes that take place in compost heaps, SLOW and STEADY wins the race.

    As suggested in your comment, a 150w bulb burns very hot, a glass enclosure is for all intensive purposes is burn proof, but the fire hazard still exists, and the odds of a fire increases with greater intensity light. The heat differential vs. distance from bulb will be vary greatly especially in an uninsulated glass container (also with an open top?). You may have an 'Easy Bake Oven' directly under your light source while the corners of the aquarium will be barely above room temperature due to the heat loss in the uninsulated glass. This is a much more expensive system which will burn 5x as much energy to create less-than-ideal fermentation conditions; I don't believe reptiles like living in the center of compost heaps.

    At the very end of the instructable, (as insulative and non-porous as a foam cooler is), I mentioned the chamber needed modification. I actually found it difficult to maintain high temperatures and humidity as this was built; the vent holes are now plugged and the leaves are now placed in twist tied plastic bags to hold the humidity. With this fix it works like a charm!

    Tried and true, cheap and easy!