Fermenting tobacco question.

[Ben Brand]

I'm fermenting some of my 2 year old tobacco again for the 2nd time, just to see if there are changes to the tobacco.

I watched a video today on fermentation, and after the tobacco reached it's desired temp, the farmer breaks down the stack to cool it down before restacking it again. He even moistens some of the tobacco before stacking it again.

Now my question! I don't ferment my tobacco in a pile, I do it my old fermenting fridge, on a temp of 55 deg C. It's been in for a week, do I leave it or take it out to cool down?
I've been fermenting in my fridge for a few years now and never took the tobacco out to cool down!

Another interesting thing the farmer said, is that he never let the tobacco go over 42 deg C, that was his ligero, the viso and seco even at lower temps, which is a bit lower than what I was doing.
I would like to hear what other members say about this.

 

[deluxestogie]

I think 55°C is fine.

I kiln all of my tobacco at about 128°F (~53°C) for 4 to 6 weeks. My only intervention is to maintain the water supply within the Crockpot which heats the kiln. I've done it that way for years.

In pile fermentation, breaking down the pile is the only method of controlling how hot it gets. Plus, the exterior of the pile is not fermenting while the interior heats. It substitutes a lot of labor for an electric bill.

My impression of intermittent "airing" or "drying", which I've tried in the past, is that it merely represents time during which the tobacco is not fermenting. Tobacco fermentation is a temperature (and moisture) dependent enzymatic reaction.

As for the lower temps, it just carries out the process more slowly. It also allows wrappers to slowly complete fermentation without becoming darker in color--sometimes desirable. Below 120°F (~49°C), the moist leaf can grow mold, whereas at temps above that, there can be no vegetative growth of mold.

Another consideration is the age of the air-cured leaf that initially goes into the kiln. If it has a year on it before kilning, the result is often nicer.

All that having been said, the kilned leaf improves significantly after weeks or months of airing/rest.

Bob

 

[ras_oscar]

I know nothing about "fermenting" tobacco. However, I do know a bit about fermenting and mashing barley for beer, as I brew on a residential scale. The first step in to turning barley or wheat to beer is called mashing. Grains are crushed, placed in a pot of water, heated to 165F and held at that temperature for about an hour. Enzymes in the husk if the grain convert the starches to sugars ( long chain sugar molecules are called starch, short chain sugar molecules are called sugar) If the temp falls below 155F, the enzymes become inactive. If the temp goes beyond 170F, the enzymes are denatures, or permanently rendered incapable of action. Based on the fact that the tobacco fermenting process is described as temperature dependent, and that steps are taken to prevent the internal temp from rising too high, I believe this enzymatic action is what is really going on in the tobacco "fermentation" process.By contrast, in brewing, great pains are taken to cultivate, preserve, and reuse desirable strains of yeast, which converts sugar to alcohol and co2 by a process brewers call fermentation. I have heard no discussions in the tobacco industry about maintaining yeast strains for this purpose.

 

[ChinaVoodoo]

I know nothing about "fermenting" tobacco. However, I do know a bit about fermenting and mashing barley for beer, as I brew on a residential scale. The first step in to turning barley or wheat to beer is called mashing. Grains are crushed, placed in a pot of water, heated to 165F and held at that temperature for about an hour. Enzymes in the husk if the grain convert the starches to sugars ( long chain sugar molecules are called starch, short chain sugar molecules are called sugar) If the temp falls below 155F, the enzymes become inactive. If the temp goes beyond 170F, the enzymes are denatures, or permanently rendered incapable of action. Based on the fact that the tobacco fermenting process is described as temperature dependent, and that steps are taken to prevent the internal temp from rising too high, I believe this enzymatic action is what is really going on in the tobacco "fermentation" process.By contrast, in brewing, great pains are taken to cultivate, preserve, and reuse desirable strains of yeast, which converts sugar to alcohol and co2 by a process brewers call fermentation. I have heard no discussions in the tobacco industry about maintaining yeast strains for this purpose.

It's nice to see you theorizing about this. The process of amylase breaking down starches and sugars is actually a part of the curing process, rather than the fermentation. The fermentation is much more about breaking down proteins that are in the leaf. Curing is similar to mashing, except it goes beyond breaking down starch into sugars, into the loss of sugars wherein "respiration" occurs, breaking sugars down into co2. Flue curing stops this process before the sugars are all lost into the atmosphere as carbon dioxide.