Most of the current research says that the so called "fermentation" of tobacco leaves is an enzymatic and chemical reaction.
Deluxestogie's Unheated Foam Fermentation Box Fiasco
- Thread starter deluxestogie
- Start date
- Status
Several studies (like Johnson's) indicate, that auto-fermentation / enzyme activity are highest between 25 and 40 degrees Celsius (77-104ºF).
Forced fermentation should therefore create suboptimal or at least different results when run at temperatures far above 40 degrees Celsius (104ºF)
But there's the issue of mould.
I tried to gather information on natural mould inhibitors and their effects on enzyme activity:
# Alcohol (ethanol) seems to stimulate oxidase/peroxidase activity at lower levels, with a sharp drop-off at 40% ethanol concentration and above. In my own experience, on the other hand, tobacco kept in about 35% alcohol never gets mouldy, but also shows no signs of fast further development.
# I found red wine (12-15% alcohol) works well against mould, and makes tobacco smoother (for the pipe), but a low pH (<4) and tannins also deactivate enzymes.
# Vinegar again has the issue of low pH, effectively deactivating oxidase/peroxidase.
# Yeast (bakers yeast, beer or wine yeast): I have two samples standing here for 2 weeks with >50% moisture content at room temperature. A fermenting fruit/wine aroma has developed, but no sign of mould so far.
Tested the tobacco now - 2 weeks of kilning at 50 degrees Celsius do more positive things to tobacco than this treatment.
(It also leaves a yeast taste, which can be "kilned out", if one doesn't like that.)
# Old books describe "fermentation" with soda or potash, and how large amounts of ammonia are released that way. Since unfermented tobacco leaf is naturally slightly acidic, it moves the pH towards 7 (enzyme activity seems to peak at pH 6.5-7). (The "Toscano" fermentation process evidently creates a similar environment through the addition of about 40% fermented tobacco.) I remoistened tobacco with a 6% natrium bicarbonate solution to a water content of about 55%, which I kept the last days at 35 degrees Celsius (95ºF). There's no sign of mould. There's also no ammonia smell.
(Interesting I find here, that the few Bethune/Petune recipes mentioned in various places frequently contain ammonium carbonate, sour wine or vinegar, rum and molasses.)
In regard to practical application, I get the feeling that for small amounts of tobacco the quest for a meaningful kiln-free fermentation at room temperature is not really leading anywhere, and that time and effort are better spent in building a decent kiln.
Jitterbugdude: I went through a lot of supposedly scientific articles over the last couple of years, and I'm astonished by how few is known on that subject. Most of the reported lab work leaves more questions than answers.
There's a review named "Tobacco fermentation, a survey" by D.J.Wood (from 1962, mind you), which points out that a lot of claims by international experts in this field are contradictory.
Forced fermentation should therefore create suboptimal or at least different results when run at temperatures far above 40 degrees Celsius (104ºF)
But there's the issue of mould.
I tried to gather information on natural mould inhibitors and their effects on enzyme activity:
# Alcohol (ethanol) seems to stimulate oxidase/peroxidase activity at lower levels, with a sharp drop-off at 40% ethanol concentration and above. In my own experience, on the other hand, tobacco kept in about 35% alcohol never gets mouldy, but also shows no signs of fast further development.
# I found red wine (12-15% alcohol) works well against mould, and makes tobacco smoother (for the pipe), but a low pH (<4) and tannins also deactivate enzymes.
# Vinegar again has the issue of low pH, effectively deactivating oxidase/peroxidase.
# Yeast (bakers yeast, beer or wine yeast): I have two samples standing here for 2 weeks with >50% moisture content at room temperature. A fermenting fruit/wine aroma has developed, but no sign of mould so far.
Tested the tobacco now - 2 weeks of kilning at 50 degrees Celsius do more positive things to tobacco than this treatment.
(It also leaves a yeast taste, which can be "kilned out", if one doesn't like that.)
# Old books describe "fermentation" with soda or potash, and how large amounts of ammonia are released that way. Since unfermented tobacco leaf is naturally slightly acidic, it moves the pH towards 7 (enzyme activity seems to peak at pH 6.5-7). (The "Toscano" fermentation process evidently creates a similar environment through the addition of about 40% fermented tobacco.) I remoistened tobacco with a 6% natrium bicarbonate solution to a water content of about 55%, which I kept the last days at 35 degrees Celsius (95ºF). There's no sign of mould. There's also no ammonia smell.
(Interesting I find here, that the few Bethune/Petune recipes mentioned in various places frequently contain ammonium carbonate, sour wine or vinegar, rum and molasses.)
In regard to practical application, I get the feeling that for small amounts of tobacco the quest for a meaningful kiln-free fermentation at room temperature is not really leading anywhere, and that time and effort are better spent in building a decent kiln.
Jitterbugdude: I went through a lot of supposedly scientific articles over the last couple of years, and I'm astonished by how few is known on that subject. Most of the reported lab work leaves more questions than answers.
There's a review named "Tobacco fermentation, a survey" by D.J.Wood (from 1962, mind you), which points out that a lot of claims by international experts in this field are contradictory.
AmaxB
Well-Known Member
An interesting thread
My current thinking on this:
- baled tobacco that is moist enough will ferment
- baled tobacco that ferments usually does not mold
- most of the bale of tobacco, though initially serving as just insulation, is capable of contributing to heat generation
- I don't grow sufficient quantities of tobacco to adequately test these ideas (without too much distress)
- "time and effort are better spent in building a decent kiln"
Bob
The underlying reaction responsible for tobacco fermentation is obviously not highly exothermic, therefore the need of a kiln that provides the heat to raise reaction rates. So where does the heat come from in a bale? When I look at a video that shows how Cuban farms build a bale it seems very similar to building a compost pile, which does produce heat.
I have been trying to use solar power to get tobacco leaves to warm up enough to ferment in a small greenhouse. My effort has mostly met with failure. The typical outcomes are leaves dry out and/or leaves grow mold. In fact I have decided to build a kiln after all my failures.
I have been trying to use solar power to get tobacco leaves to warm up enough to ferment in a small greenhouse. My effort has mostly met with failure. The typical outcomes are leaves dry out and/or leaves grow mold. In fact I have decided to build a kiln after all my failures.
- Status
Similar threads
