Tobacco Fermentation and Aging

[alfredo_buscatti]

A few years ago a gifted pipe friend wrote a very long reply to questions that I posed about aging. I think it's one of the best analyses that I've read.

Posted here for your pleasure and edification.

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Tobacco Fermentation/Aging
by Vito

(one of three)

Can "melding" be called fermentation loosely, in the same way aging is also loosely called fermentation?
I wouldn't call melding fermentation at all. If it's proper to call aging "fermentation", then I would say that melding is something that happens during fermentation, but I wouldn't say that melding and fermentation are even roughly the same thing.

Melding is something that happens to blended tobacco during aging. Melding refers to the commingling of the flavors of the various component tobaccos to create something that doesn't exist before the melding has occurred.

(snip)
In general, fermentation processes involve the conversion of sugars to other substances, like alcohol. Here again, the processes have to be controlled so that they produce the desired result. You can't make alcohol without sufficient moisture, so that's why the aging process requires leaf that is relatively dry. Then you get other, more complex organic compounds, but it takes them longer to form.
&&&&& You've lost me when you say "You can't make alcohol without sufficient moisture, so that's why the aging process requires leaf that is relatively dry. Then you get other, more complex organic compounds, but it takes them longer to form."
I've never found aging to produce alcohol in weed.
Whoa...back up. Sounds like you got almost the exact opposite of what I was trying to say. I didn't say there's alcohol in aged weed (although I wouldn't be surprised if there is a small amount).

Let's start over. Fermentation converts sugars to other substances. One of them is alcohol -- probably one of the most familiar. That's the "desired result" for people who use fermentation to produce alcoholic beverages. Bakers desire a different result when they use fermentation (yeast) to make bread dough rise before baking. In that case, they're not looking to produce alcohol; rather, they want to produce lots of gas (carbon dioxide), the bubbles of which expand the dough mass and make it less dense -- hence, light fluffy bread after it has baked, rather than a much denser, smaller glom of baked dough that hasn't been allowed to rise and fluff itself out. (BTW, the fermentation process that occurs when dough rises actually does produce alcohol -- quite a bit of it, actually -- but it all gets quickly evaporated during baking.)

The point is that in each case, the people who are using fermentation control the conditions to get the desired results. Now, in weed aging, we don't particularly want either alcohol or carbon dioxide. So how do we prevent, say, alcohol from forming? Well, you can't make alcohol without sufficient moisture, so if you don't want alcohol (we don't), don't start out with very moist weed. Limiting the moisture level at the start is one of the controlled conditions we use to get the result we want.
And the second sentence refers, I guess, to aged 'baccy, especially as regards "more complex organic compounds." You are saying that aged tobacco has more complex organic compounds than its unaged brethren?
Actually, what I'm saying is that aged tobacco has different complex organic compounds than its unaged brethren, but the comparison I was making via the phrase "other, more complex organic compounds" was not referring to the unaged weed, but rather to the kind of fermentation process that produces alcohol. We don't want alcohol when we age pipeweed...at least I don't.

Time to back up again. Remember, fermentation converts sugars to other substances. Well, if alcohol is NOT one of the organic substances that we want to produce during weed aging, then what other substances do we want to produce? Obviously, it's the complex esters and phenols that result from aging -- substances that show up as "fruity" notes when you first crack a tin that has been aging for 10 years. Those substances are more complex than alcohol. That's what the "more complex" referred to.

Now, go back and read it again. Here's the translation: Fermentation turns sugar into different things. Alcohol is one of them, but we don't want alcohol, so we control the process in a way that doesn't give us alcohol, and one of those controls is low moisture at the start of the process. So, the sugar turns into different organic substances that are more complex than alcohol, but it takes longer to make them. See?

V

Tobacco Fermentation (2 of three)

"The simplest way to answer is to say that fermentation is really a kind of controlled decomposition. It literally changes the substances that are fermenting via various chemical processes that decompose them, but in a controlled way that produces and end result that is desirable."
If we knew where we were going in aging tobacco, by the chemical analysis, above, we could then know how to steer aging and thereby come more into line with your quote that defines fermentation. This would be "controlled" aging with a known, desirable,*result.
Tobacco Fermentation (3 of 3)
The simplest way to answer is to say that fermentation is really a kind of controlled decomposition. It literally changes the substances that are fermenting via various chemical processes that decompose them, but in a controlled way that produces an end result that is desirable.

As far as the role of heat is concerned, it's merely a catalyst. It usually accelerates any chemical process. Sometimes the heat is generated by the process itself, in which case it's called an exothermic reaction -- one that generates heat as one of the effects or by-products of the process. When that happens, some of the energy that's locked up in the molecules of the unfermented substance is liberated in the form of heat by the chemical processes that are at work.

Heat can also be induced simply by increasing the pressure on a given substance. I've explained how that happens in earlier posts, wherein I've also explained why that accelerates the "melding" process that occurs in blended weedage.

The key is to make all these processes occur in a controlled way. For example, when they age tobacco leaves to create maduro leaf for cigars, what they're really doing is creating the early stages of the same process that occurs in composting. However, in the case of maduro leaf production, they watch the leaves very carefully, turning them often to air them out, cool them, and thereby prevent them from actually composting. If they didn't, the leaf would soon cook itself into mush. They have to be very careful to start with leaf that has already dried out (cured) to a great extent. Green leaf would begin composting almost immediately. In fact, in the absence of sufficient air, it wouldn't even compost; instead, it would literally turn to ****.

I'm not kidding. It's the same process that happens to grass inside a cow's stomach. You can try it yourself. Take some green grass clippings and pile them up; use enough to make a big pile...say 3 ft. in diameter and 2.5 ft. high. Give it a week or two, and then come back and dig down to look at the stuff in the middle of the very bottom of the pile. It's now greenish brown goo, very hot, and it smells like cow ****. But if you mix an equal quantity of brown matter (dead leaves, sawdust, or other dried organic material) with the green grass clippings when you make the pile of stuff, and if you turn it every day or two to air it out, bringing the stuff on the bottom to the top and vice versa, in a couple of weeks you'll have rich, brown sweet-smelling compost -- a gold mine of nutritious stuff for your organic garden. I've been doing it for years.

In general, fermentation processes involve the conversion of sugars to other substances, like alcohol. Here again, the processes have to be controlled so that they produce the desired result. You can't make alcohol without sufficient moisture, so that's why the aging process requires leaf that is relatively dry. Then you get other, more complex organic compounds, but it takes them longer to form.

Another by-product of fermentation is various gasses, the most common of which is carbon dioxide. Here again, it's important that the weed be relatively dry; otherwise, the carbon dioxide would go into solution in any free water molecules it finds and become carbonic acid, the stuff that's in soft drinks like Coca-Cola. It's reasonably corrosive stuff, and it would chew up the weed and decompose it into mush if the weed started out too wet in the first place.

I'm not totally clear on the degree to which the process that occurs in weed aging can properly be called "fermentation". I suppose it is fermentation of a sort, at least according to the definition in your message, but that definition isn't actually very specific.* To wit:
...various enzymatic transformations...
...various controlled aerobic or anaerobic processes...
...various industrial processes...
Those are all very non-specific descriptions, which only serve to make the term "fermentation" cover a pretty wide range of processes. It doesn't make it particularly easy for inquiring minds like yours and mine to understand what actually happens in weed aging with any great specificity or to any great depth.

For example, is it really accurate or particularly enlightening to say that the process that occurs inside an oak cask containing the juices expressed from pinot noir grapes is the same as the process that occurs inside a tin of Christmas Cheer pipe tobacco? One is mostly liquid, and the other contains very little moisture by comparison. So, if we call both processes "fermentation", how much does that really tell us about what's happening in either case? We certainly don't get the same results from each process.

This is a subject that I've written about before. I believe that, while a great deal is known about the kind of "fermentation" that occurs in wine making, relatively little is known about the kind of "fermentation" that occurs in weed aging. If I had a lot more time on my hands and the budget to support it, I would love to put together a research program to unpack the mysteries of the weed aging process in a scientific way.

The benefits are obvious...at least to me. What if we could understand enough about the weed aging process such that, given a weed (or a blend of weedages) of certain characteristics (moisture content, sugar concentration, and any number of other quantifiable parameters), we could enhance the conditions under which the weed would age? What if we could "seed" the weed with anaerobic organisms (or substances that would encourage their growth), such that they would perform their magic in one year rather than five years? By their very nature, such substances would not taint or pollute the tobacco; the anaerobic bugs would consume them in doing their job!

One of the reasons we don't understand such processes is that they are complex. I don't mean "complicated", although they certainly are that too. In science, "complexity" doesn't mean "complicatedness"; it means that you can't understand something fully by dissecting it into its components without destroying the very phenomenon that you're trying to understand. It means that you can't represent the system with a single mathematical algorithm — an equation — that explains or describes everything there is to know about what it is and how it works. Complex systems are the ones that physics doesn't know how to handle. It's not equipped to handle them, epistemologically. In a sense, the stuff that physics tackles are the easy problems. I know -- that sounds crazy; most people would think that, say, nuclear physics or relativistic quantum mechanics hardly qualify as "easy subjects", but it's true. They deal with simple systems, and simple systems yield to reductionist methods. Complex systems are a whole 'nother thing entirely.

Complexity theory is my chosen area of expertise. It's really the new frontier of science -- one that's much more fascinating and compelling than, say, subatomic physics or M-theory (formerly known as "string theory"). Why? Because complexity is at work everywhere in our world -- the world that we immediately apprehend with our senses. Ultimately, it holds the answers to many of the biggest questions that physics has ignored because it doesn't know how to unpack them, from matters like the emergence of life itself, to the nature of consciousness, to the creation of a stabilized, durable, advanced civilization free from the destructive interactions that have plagued our species' entire history. I'm not taking anything away from those aspects of science that plumb the depths of the microcosmic world beyond the abilities of our senses; all I'm saying is that, while I find them fascinating, I don't find them particularly urgent.

The truth is that our species has advanced its knowledge of physical systems at a pace that has vastly outstripped the growth of our knowledge in areas like "How in hell can we live with each other without destroying ourselves?" We are smart enough to create the means to destroy our species and the world we live in, but it's not entirely clear to me that we're smart enough to figure out how to prevent that from happening.