Why do Cuban cigars need lower humidity?

[canadianbeaver]

When you write like this piggy it makes up for the fact that you hate Neil Young. Thank you!

[mash]

My friend, whether by accident or design, you have captured the essence of the debate in this and your other posts. I hope you don't mind me using them as an example.

rH alone means nothing! Please read that again so you (meaning all readers) understand it. rH, mentioned without a corresponding temperature is meaningless!!! I can prove this, or you can to yourself via a psychrometric chart of humidity.

I have a half written somewhat formal analysis on this that topic that I will post someday; not today unfortunately.

In essence you are not storing air in your humidor, you are storing cigars. Cigars conditioned by the very water vapor, not air, that exists in your humidor. Air is meaningless. Air is only a medium that assists in the transfer of heat and has noting to do with water content of your cigars!

Water vapor is the essence of the properly conditioned cigar. Water vapor content is not independent of, but linked to temperature. Water vapor is not the only variable. This is where most people get lost. Temperature is as important, or more so than water vapor itself. I can prove this, I just won't be doing it today!!

In order to understand, not utilize, but actually understand cigar storage you need to understand the hygroscopic nature of things. Tobacco is a hygroscopic "thing." Hygroscopicity is dependent on the physical nature of things. It is dependent on two equal parts. Those parts are temperature and humidity. The relationship is visualized by the isothermal chart of the "thing."

Water activity in all "things" are not equal or linear to the equilibrium vapor pressure of water. There are two, actually three including pressure, that affect water content. Temperature is as important, if not perhaps more important than rH.

While happy to share my opinion regarding the sweet spot for storing cigars, it is unimportant when contrasted to the information above. Storing cigars is easy. Understanding storing cigars is a lesson in science.

Happy smoking! -the Pig

RH alone is not meaningless. If you keep the temperature a constant, RH differences are still relevant. I keep my humidors at a steady temp. If I keep the RH at 63 vs, 70%, there is a noticeable difference in how my cigars smoke. The point is that at a given temperature, Cubans tend to smoke differently at the same RH as non-Cubans.

If your argument is that the effect of storing at a given RH varies with the temp, that's true.

[Colt45]

Water vapor is the essence of the properly conditioned cigar.

Can we use hygrometer rh as a general indicator?

[PigFish]

RH alone is not meaningless. If you keep the temperature a constant, RH differences are still relevant. I keep my humidors at a steady temp. If I keep the RH at 63 vs, 70%, there is a noticeable difference in how my cigars smoke. The point is that at a given temperature, Cubans tend to smoke differently at the same RH as non-Cubans.

If your argument is that the effect of storing at a given RH varies with the temp, that's true.

... no offense! You have contradicted your own statement. Please re-read what you have written. You have mentioned "constant temperature." You have therefore at least implied a temperature. You have clearly stated rH at a given temperature, neglecting to indicate that temperature.

You have indicated, for example that 65 rh @ 70 dF is different than 66 rH @ 70 dF. This is true! If you leave off the corresponding temperature, the statement is false, or at least it can be proven to be!

rH alone is meaningless. I stand by that statement. Please prove me wrong and tell me how many grains of water exists in 70rH air.

I'll be here drumming my fingers waiting for you to ask me at what temperature I want the calculations based on! This is indeed the point of my post.

-Cheers

-Piggy

[Orion21]

It also depends on how you store your cigars. Singles, boxes (of several types), cabs or varnished . . .

The water vapor, as Ray refers to, will be absorbed and transferred to and from your cigars by the packaging at different rates. Also, if you store your cigars loose as singles, like many guys I know do, that is a game changer as well. High, low or in the middle of your humidor - in the back, front or middle of the space etc. Basically, there too many FRAKing variables to to give anyone a definite answer on one aspect of cigar storage - rh.

All of my cigars have different water content. My cigars at the bottle of my wineador tend to be a little "drier" than those at the top. My boxes wrapped in paper tend to be "drier" than my cabs . . . It comes down to knowing your storage space. I know my storage space and the results have spoken for themselves.

To make you happy, on my hydrometer I try to target no more than 65% at the top of my humidor and no lower than 62% at the bottom. Those numbers are at 60F.

[PigFish]

Can we use hygrometer rh as a general indicator?

Of course! As suggested cigars are very forgiving. What is more tobacco varies. There is no right answer. When considering errors, tastes and opinions the ranges of answers are infinite.

My point was that when a guy says he keeps his/her cigars at 65rH he/she makes a partial statement. There are differing amounts of water in tobacco at equilibrium at 65rH at 70 dF and at 65rH at 75 dF. One number without the other is meaningless!

As we start to examine an envelope of conditions, I postulate that temperature is every bit as important as rH. I have papers on experiments that show this to be true. I say postulate because I have not proven this myself as independent work.

Ask yourself this Ross. If you put your cigars in a freezer and keep it at 65 rH do you think that the water content will be the same as in your humidor at 70 dF? So there in lies the answer to your question. Within an envelope of temperature one can use a hygrometer as an indicator of ErH water content in your cigars. You cannot vary the temperature without a correspondingly important effect!

You have to assume a temperature before you can even claim to use a hygrometer as a tool to test the ErH water content of the cigar. Using a hygrometer, assumes a given envelope of temperature...

Cheers. -Ray

[Orion21]

I hope I get this right, but I think if temperature doesn't change the rate of adsorption doesn't change. Adsorption and desorption are what we are all really thinking about when we think of temperature and rh levels as it relates to how "wet" or "dry" our cigars happen to be..

P.S. I use fans in my wineador. I was talking in hypothetical terms because it is impossible for use to measure temp and rh levels at every point in our humidors. We can generalize, but that really as far as we can go.

[Guybrush]

rH alone is meaningless. I stand by that statement. Please prove me wrong and tell me how many grains of water exists in 70rH air.

I'll be here drumming my fingers waiting for you to ask me at what temperature I want the calculations based on! This is indeed the point of my post.

At 0° Celsius 70% is 3,43 g water/m³

At 20° Celsius 70% is 12,11 g water/m³

But don't forget about the kinetic theory of gases.

More water in the air (because of the temperature) does not necessarily mean more water in the cigar!

65-70% should be right, and you can ignore the temperature and the thereby existing different amounts of water in the air.

Unfortunately I only know a German site to explain this in more detail:

http://www.humidorbau.de/info/relative-luftfeuchte.html

[PigFish]

We are now really adding to my point, expanded beyond my intent.

I will write some time permitting.

How about tobacco?

Please publish (post) your tobacco isotherms. The isothermal charts for tobacco will spell it out. I have some resources here and I will post about it when I post my article regarding same.

The statement regarding equilibrium water vapor surrounding a cigar can be true. It depends on the temperature and the isotherm of the tobacco itself.

Ultimately we are not talking rH. We are talking percent water content of tobacco. Percent water content of tobacco is relative to both temperature of the tobacco and the rH of the environment that it is stored. This brings me back to my point.

rH alone is meaningless. It not only does not reflect the absolute water content in the environment, it does not then relate to the state of tobacco as a hygroscopic substance. Hygroscopicity of tobacco, its isothermal characteristics are dependent not only on ErH but its temperature. Thus the terms iso-therm.

I am not going to take away from anyone's opinion on the topic! I would like to read more of the aforementioned authority on the subject. I have read opinions regarding percent moisture content of tobacco stipulating that it is only dependent on rH. I proffer, if one makes claims that percentage moisture content of tobacco has no relation to temperature, and is based solely on rH, that person is clueless!!!

Good conversation my friends!

Cheers. -Piggy

[UpInSmoak]

All this science is super confusing. For the layman out there what does all this mean?

I personally, smoke my cigars at 60rh at room temperature as my my humidors have no cooling technology. I use to store and age at 65rh at room temperature. I say use to because that will be changing this weekend. After much reading I've decided to side with MRN and others who believe long term storage should be done at 60rh and ziplocked for minimal airflow.

Ray, I would love your thoughts on this as I respect your knowledge in this matter. What are the best conditions to age considering temperature will maintain at room temp at approx 70dF?

Anyone else care to chime in? Sorry for the thread jack, perhaps I'll start a new one!

[mk05]

All this science is super confusing. For the layman out there what does all this mean?

Well to make it really simple, think about "relative humidity," in the way that humidity is relative to the temperature. There are many articles written for nerdy cigar collectors out there. I'll try to dig up a pdf I was forwarded.

Basically, say you started at a given environment, 60dF and 60%. If you boost the temperature, the humidity, relative to the temperature, will fluctuate higher due to air being able to hold more water in higher temps.

[Guybrush]

I found something in English. Perhaps this helps.

http://en.allexperts.com/q/Cigars-2143/2008/12/Temp-VS-humidity-table.htm

[LeafLover]

60rh. I can smoke right out the box.

[mash]

We are now really adding to my point, expanded beyond my intent.

I will write some time permitting.

How about tobacco?

Please publish (post) your tobacco isotherms. The isothermal charts for tobacco will spell it out. I have some resources here and I will post about it when I post my article regarding same.

The statement regarding equilibrium water vapor surrounding a cigar can be true. It depends on the temperature and the isotherm of the tobacco itself.

Ultimately we are not talking rH. We are talking percent water content of tobacco. Percent water content of tobacco is relative to both temperature of the tobacco and the rH of the environment that it is stored. This brings me back to my point.

rH alone is meaningless. It not only does not reflect the absolute water content in the environment, it does not then relate to the state of tobacco as a hygroscopic substance. Hygroscopicity of tobacco, its isothermal characteristics are dependent not only on ErH but its temperature. Thus the terms iso-therm.

I am not going to take away from anyone's opinion on the topic! I would like to read more of the aforementioned authority on the subject. I have read opinions regarding percent moisture content of tobacco stipulating that it is only dependent on rH. I proffer, if one makes claims that percentage moisture content of tobacco has no relation to temperature, and is based solely on rH, that person is clueless!!!

Good conversation my friends!

Cheers. -Piggy

Jesus Ray, you lost me several posts ago.

My simplistic way of looking at it is this- at a temp in the mid 60's, where I store my cigars, I am exposing them to less humidity at 63% than I am at 70%. That way, the cigars burn and taste better. With non-cubans, they are more tolerant of a higher RH, and they don't taste as hot. Is there a quiz at the end of this?

[David67]

O boy, I've really opened up a can of worms with this one

But thanks for all the thoughts people have put forward. Yes, I should have mentioned temp, I keep mine at about 18 to 20 degrees centigrade.

I know it is personal taste but most people I have asked do tend to want their Cubans at a lower humidity.

[BMack]

I read an interesting post a couple days ago that seems to correlate with what I see in the real world...It's from another forum but I will just copy and paste it here. The person that posted it is Steve Saka of Liga Privada/Drew Estates:

WARNING: if you are a normal cigar smoker, then this post is a real boring, whacko, anal, WTF kind of stuff that no one really needs to know and I strongly suggest you save yourself 10 minutes of your life and do something more useful like sorting your sock drawer than reading it.

Consider yourself warned!

===

Background: Ever since I have been online and discussing cigar storage one of the questions that repeatedly comes up is the fact that RH varies with temperature and therefore we should be storing our cigars at varying RH depending on the temperature. There is plenty of widely available scientific dissertations explaining this RH to Temp relationship, however even though the science always seemed correct, my actual real life experience didn't bear this out. Below is how I finally came to conclude that RH is RH is RH when discussing cigar storage in a humidor-like environment.

===

Fwiw, this question of temperature and its impact on relative humidity levels and what that actually means in regards to absolute humidity use to drive me crazy. I read a ton of stuff by a lot of scientifically minded folks explaining to me how it has a definite impact. And when I read it all, it made sense...

BUT, my own personal experience never beared this out. It seemed like about 70% RH was right regardless of temperature.

So I decided to do a large scale test.

First, let me say that the RH is the not the actual goal when it comes to cigar storage moisture wise. What you really want to have happen is for the absolute moisture content of a handmade cigar to fall between 10% to 12% (or if you are like me, 9% for heavy bodied cigars.)

The problem for the average joe is you need a very sophisticated moisture meter that has been specifically calibrated for air cured, leaf tobaccos. The cheapest I have ever found that was trustworthy costs about $1900 USD and is sold by ATM in Holland.

Anyhow, I own two...

So I got the fancy meter, I got 300 identical cigars, I got three humidors loaded with 100 cigars each and each with an RH Standard - one with 65%, one with 67% and the third with 70%, and as it would so happen I actually had access to a temperature controlled insulated storage room where I could vary the temp from 45 degrees to 90 degrees.

I tested the cigars from all three humidors at 5 different temp levels with a fixed RH and the in the end the moisture content actually contained in the cigars varied by less than .25% all the way from 45 degrees to 90 degrees.

So personally I had come to the conclusion that I could ignore the temp, go for the desired RH and the resulting storage environment moisture wise would be A-OK. In short, ignore everything I read about temp vs rh and the fancy graphs and just try to establish a 70% RH.

However, it still drove me crazy not understanding why my own tests seemed so contradictory to what others were so adamant about and had plenty of scientific writings to confirm their viewpoint.

===

So I asked an cigar smoking acquaintance of mine who happen to be a Doctor of Chemistry from UC Berkeley, Dr. Robert Chasteler, if he could shed any light on this. In my opinion, this guy is 100 times smarter than me so I figured maybe he could explain me why the Science vs. My Own Realword Expeiences weren't jibing.

And here is his reply to me from October 17, 2000:

===

Steve,

This ended up being harder than I thought. Being a scientist by education I guess I just grasp the concept so easily. But while smoking my evening stogie last nite it came to me how to do it. I have included the easy description for the non-scientific minded and then delve a little into the scientific concepts. Any questions regarding this just ask. If you decide to use it just remember to give credit where cigars (I mean credit) is due.

Absolute vs. Relative (the final solution)

==========================================

The key premise we must all agree upon is that the goal we wish to achieve is to keep a constant amount of moisture in our cigars.

The definition of relative humidity is the vapor pressure of water in the

atmosphere relative to maximum vapor pressure of water that the atmosphere can sustain. The maximum amount of vapor pressure of water that can be sustained in the atmosphere is temperature dependent. This is due to the fact that as the temperature rises, more water will evaporate due to the increased temperature. This argument holds true whether the water is coming from a dish of water or any object that contains water, like a cigar.

A cigar is in a closed system when the temperature is raised will cause

water from the cigar to evaporate increasing the vapor pressure of water in the atmosphere. If something in the system is keeping the vapor pressure of water in the atmosphere constant, the cigar will keep drying out until a new equilibrium inside the cigar is reached and the cellular structure won't give off any more water at that temperature. But the net effect is the moisture content is decreased and a dry stogie results.

The reverse situation also will cause problems. Again a cigar is a closed system when the temperature is lowered. It will absorb some of the water vapor since the temperature can only maintain so much water in the vapor phase. If something in the system is keeping the vapor pressure of water in the atmosphere constant, the cigar will keep absorbing water again until the cellular structure is overloaded with water. The net effect here is the moisture content in the cigar increased and now you have a wet stogie.

If some device is in the system, which will keep the relative humidity

constant (that is as the temperature rises it will increase the water vapor pressure proportionately and as the temperature lowers will decrease the water vapor pressure proportionately) the problem is solved. In the increase temperature situation the cigar will try to evaporate more moisture but the vapor pressure of water in the atmosphere is already great enough not to evaporate any. And in the decreased temperature situation the cigar will want to absorb more water but the vapor pressure has already been lowered.

Now the above argument only truly holds true for a cigar with a substantial amount of contained water. A very dry cigar (< 1% water) will skew this logic since now the cellular structure's affinity for water will over power the evaporation due to the increase in temperature. One has to have cigar that have equilibrated to some reasonable moisture content (keep them in a humidor at 70 degrees F and 70% relative humidity until the system stabilizes).

A more scientific derivation is below:

--------------------------------------

The physical laws that are governing this situation is the process of

evaporation and absorption. The formula for evaporation from a dish of water is:

Rate of evaporation = Constant1 * Temperature * Temperature/Vapor

Pressure of Water

The formula for absorption into a dish of water is:

Rate of absorption = Constant2 * Vapor Pressure of Water

Equilibrium is when the two rates equal each other.

Rearranging yields:

Vapor Pressure of Water = Temperature * Constant3

Where Constant3 is a mathematical expression of Constant1 and Constant2 and is insignificant since the net result is that the Vapor Pressure of Water is directly proportional to the Temperature. This is exact behavior of the maximum vapor pressure of water in the atmosphere.

The same equations for a cigar are only slightly different since now one

must include the Water Content in the cigar as a variable. Here are the new equations:

Evaporation = Constant1*Temperature*Temperature*Water Content/Vapor Pressure of Water

Absorption = Constant2 * Vapor Pressure of Water/Water Content

In a system with constant temperature and water vapor pressure (in an ideal humidor 70/70), if the Water Content is too high the Evaporation rate will larger than the Absorption rate and the cigar will dry out until equilibrium is reached. And the inverse works for a too dry cigar. This is how our humidors do their job.

For a cigar at equilibrium (70/70 system), the Water Content can now be moved into the Constants since it is now a constant also. In this system we are going to keep the relative humidity constant. If the Temperature is raised 5%, the Vapor Pressure of Water will increase proportionately, 5%, from the first set of equations. For the cigar equations the rate of evaporation will go only go up 5% since the increase in Vapor Pressure of Water cancels one of the Temperature increase. But the rate of absorption will go up 5% also and no change in the cigar.

Bottom line, Relative Humidity is the way to go.

Dr. Bob Chasteler

====

So there you go. Do with it what you will, but for me RH is RH is RH when it comes to cigar storage in closed environment.

Steve Saka

Drew Estate, CEO

[Deodato]

I read an interesting post a couple days ago that seems to correlate with what I see in the real world...It's from another forum but I will just copy and paste it here. The person that posted it is Steve Saka of Liga Privada/Drew Estates:

BMack - thank you for posting that. I actually understood it and can relate both Steve and Bob's comments to to my own experiences and situation. Good one!

[kodebusan]

So do you change cultures when you go from smoking Cubans to non-Cubans, or is there another reason why you prefer to smoke Cubans drier?

No one's trying to tell anyone what to do. The point is, it's common for people to say that the optimal smoking humidity for Cubans is less than for non-Cubans. Why is that?

In fact i do change culture by smoking NC (in France for a long time mostly only CC were available along few Dominican, it has changed since few years now), and i discover NC abroad. At first i didn't like them when smoked around 70% then a friend of mine advise me to smoke them more moist and then i found some serious good cigars.

For only explanation that was given to me about this increase of humidity was that the NC tobacco were more hygroscopic and therefore can support more humidity than CC. Since then i found to like Nica around 75% and Ashton VSG around 80%.

[PigFish]

More guru theory… real short on empirical data. All this talk about gasses, so little talk of tobacco!

Some of this aforementioned is correct, other parts pure speculation. The correct is in the percent moisture content of tobacco. That is the goal. The question is then; how do we affect it?

I am not going to write a ton here as defending my honor from gauntlets tossed down by guru proxies is not really my gig!

None of these folks have isosteric rH charts for tobacco or they would publish them and prove themselves correct. Without same, they are guessing. BS theories out of pseudo science is nothing new. They make news all the time! Hell… you go to Hollywood and make a movie and you are an instant expert on the subject! That is society I guess!

I have been presented with a theory. That theory states that rH is the “only” factor to percentage moisture content of tobacco. Lets not pull punches. That is what the ‘theory’ states. I guess if you get a doctor to say it that makes it right. As a side note, I know doctors that are atheists and believers! The doctorate proves that some people went to school and received credentials. It says nothing factual about the nature of the individual… So which doctor is right, the atheist or the believer? We can all stew on that one for a while.

In the mean time I am going over to AutoCAD and plot some lines. You look at the charts and you decide for yourself.

Frankly, proving this is not all that important to me. I am my own harshest critic. I went looking for answers to questions and I think I found them. I was going to post a paper about it, perhaps elevating me too, to guru status. I reject gurus. Therefore elevating me to climate guru status is not at all important to me. I may never finish the paper. But perhaps if I do I can get a doctor to endorse it! I will be a guru then for sure!!! -LOL

Forget the footnotes, I am not going to waste my time on it. This is not original work, but taken from a study of burly tobacco researched by a major cigarette company. I would have to find the original paper, but as I recall it dates back to the 50’s

As a side note, this is not Cuban tobacco leaf. It is information derived not by pseudo-scientist hacks (like me!) but by folks who make billions selling their product to the masses. You decide whether the profit motive makes for better research or not. That is up to you.

This logarithmic chart is the basis of my theories. It was derived via a scientific method, believe me or not… to determine a means by which a tobacco company could retain the percentage moisture content of their product under various conditions. These guys are rolling millions of cigarettes in huge factories. Therefore the intersection of the desired moisture content line to that of the rH and temp is important to them. Changing climate means using energy. Energy costs money. Higher cost means more expensive products… You get the picture. This is science for a profit. There is no profit in lying about it.

On the chart you will see the curved lines that represent isothermic data on the temperature of tobacco samples. The Y axis represents percent moisture content. The X axis represents rH.

The open ended box line represents the difference in percent moisture content of tobacco over a range of 35dF. I added this while redrawing the chart in CAD. That range represents percent moisture content of tobacco over the temperature range where 60rH is kept constant.

What do you see? If you are not blind you see a direct correlation between storage temperature and percent moisture content in an isosteric rH environment!

Gurus… Put that in your pipe and smoke it! Read it a weep folks. I rest my case.

Cheers. –The Pig

[PigFish]

Jesus Ray, you lost me several posts ago.

My simplistic way of looking at it is this- at a temp in the mid 60's, where I store my cigars, I am exposing them to less humidity at 63% than I am at 70%. That way, the cigars burn and taste better. With non-cubans, they are more tolerant of a higher RH, and they don't taste as hot. Is there a quiz at the end of this?

Mate... The goal of my involvement here was multifaceted. First I wanted to all talk the same language. Ultimately this turned into a guru-cock fight over theories.

I am a firm believer that temperature plays an important role in percent moisture content. We do not roll our own cigars. The only thing that we can control is how we store them and when we smoke them.

I believe that percent moisture content plays a major role in the smoking experience. I only want the best smoking experiences. I therefore emulate my best smoking experiences... Storage conditions are a part of that equation for me. It is not for everyone!

If I add a cup of sugar to a recipe and get what I like as a result, it makes sense that when I remake the recipe I do it the same way. This is simple logic for simple people... like me! By repeating great experiences I will enhance my life. This is the basis for Piggy's theory on smoking and storing cigars.

Cheers matey! -Ray

[PigFish]

All this science is super confusing. For the layman out there what does all this mean?

I personally, smoke my cigars at 60rh at room temperature as my my humidors have no cooling technology. I use to store and age at 65rh at room temperature. I say use to because that will be changing this weekend. After much reading I've decided to side with MRN and others who believe long term storage should be done at 60rh and ziplocked for minimal airflow.

Ray, I would love your thoughts on this as I respect your knowledge in this matter. What are the best conditions to age considering temperature will maintain at room temp at approx 70dF?

Anyone else care to chime in? Sorry for the thread jack, perhaps I'll start a new one!

My friend I appreciate your trust and respect. Thank you!

I have no real theories on aging cigars. Why? Because my theories are based on empirical and factual data. I cannot smoke the same cigar twice. I therefore have no means to prove anything to myself or others. This is the realm of the guru. The guru makes claims that no one can possibly prove or disprove and crowns himself with the title of expert.

If I were a charlatan, or perhaps a collector wanting to increase my standing the community, or perhaps make my collection worth more, I could fabricate the stories to influence people to my advantage. I don't do such things. I have a nose for BS and I don't like it. I therefore don't BS others.

I could write a lot about thoughts on current trends on aging... They might cause you to think about what you are doing but nothing would be proven or evidenced. I like academic conversation, but building theories over nothing better than guesswork is not my forte.

If you have specific questions about storage I will answer them if I can. If you want to preserve your cigars I suggest that you keep them relatively stable in the condition that you like to smoke them. This is my best advice. This is what I do!!!

Cheers, -Ray

[mk05]

Well as laws of thermodynamics would have it, there are documented correlations between humidity, temperature, and pressure.

Nice chart.

[Colt45]

Of course! ......

Thanks Ray. I've a kind of off-beat question..... Let's say my cigar storage container is impervious to external humidity, but can be affected by temperature. In this scenario, the only moisture is that within said container - air and / or cigars. Knowing that the warmer the air, the greater it's capacity to hold water vapor, were temperature to increase, should I expect my hygro rh to drop?

[NJP]

Long live the pig. I reckon a yellow brick road leads to the pigs house. Love your work Ray.

[PigFish]

Thanks Ray. I've a kind of off-beat question..... Let's say my cigar storage container is impervious to external humidity, but can be affected by temperature. In this scenario, the only moisture is that within said container - air and / or cigars. Knowing that the warmer the air, the greater it's capacity to hold water vapor, were temperature to increase, should I expect my hygro rh to drop?

Here is the long and short of it Ross.

First lets look at water vapor alone. I say this because technically air does not matter. Water will create the same vapor pressure in a vessel that is void of air. Air does not bond to water vapor, it resides with it. This is the real beauty of rH. Water is not "held in air." Water vapor is a part of air!

So to answer you. Remove all your cigars and anything hygroscopic in your humidor (rhetorically speaking) and when your temperature rises, water vapor remains constant (absolute humidity) and the rH drops... End of story in the perfect world that is the way water vapor behaves.

We are not storing water vapor, we are storing cigars. So what happens to the cigars is the ultimate answer, moving away from the data of rH.

This answer is pretty simple when you look at the chart. What happens when you raise the temperature on the chart? The tobacco gives up water vapor. But several things have happened here. The temperature increased, as a result rH dropped and your equilibrium environment went negative Delta rH and positive Delta T. The items in you humidor, such as your cigars, go to work on the environment according to their hysteresis. The energy stored in the air moves to the the cigars (of which water vapor is a part) and they begin to also lose water vapor to lessen the Delta rH.

If you look at the chart, move your finger down from one isothermal line to another and in any case where rH is either static or decreases, the change will cause a loss in percentage moisture content of the cigar. In this case high concentrations are moving to the lower. Ultimately, because cigars hold more water than the space above them in the humidor, they give up very little to bring the environment back to where all the water activity is equal and everything is the same temperature.

As a side note I kinda' figured this thread was dead! That happens a lot when I go'a mythbustin' through the forum!!! Some will likely gloss over this, many will dismiss it because they cannot be swayed away from the myths that a guru leads them, and other still just because I said it and it would gaul them to let right winger Ray affect their life...-LOL

From my perspective this is earth shattering stuff! I see this as a monumental statement about myths, guru worship and cigar storage. I was saving it for the right time. I have known much of this for years now but had to be goaded to spit it out here and now.

I wrote some about the process that brought me here last night and since I figured the thread was dead I did not post it. I think I will now... Thanks for that!

Your friend, Ray

I thought I would add a little to this after sitting with my horses and contemplating a little.

Some of you might wonder how I got here?

As many of you know I build climate controlled humidors. I also have considerable knowledge of desiccant use for cigar climatology buffers.

In my trials and tribulations of building humidors I began to notice something. As I turned my temperature down, it appeared to me that my cigars actually got wetter.

In years past, before I really dedicated myself to learning cigar climatology I was a believer in the absolute humidity theory. I was convinced that it must absolute humidity content that drove the condition of the cigar. I think still, looking back at it, that this is logical, yet incorrect assumption. I never really argued it as I could not prove my case. I could not prove my case because there was no proof!

In the years since I started building humidors I began to notice empirical evidence contrary to what I BELIEVED. I emphasized believe because as noted earlier, I could not prove it. Since I am open minded I began to question my belief and started to follow what I was proving to myself empirically every time I tested a humidor and smoked the cigars stored it in. The smoking experience of course, could not be proven, not to anyone… Smoking experience is not proof! I was reluctant to discuss my findings because it was pure speculation and frankly it was antithetical to what I believed.

As I got more into desiccant science I began to learn a lot about the hygroscopic nature of “things.” I was introduced to the isotherm, or isothermal chart that depicted desiccant performance. Studying desiccant performance is not a far cry from studying cigars. They are judged by percent moisture content and total water content by weight at saturation. The percentage moisture content of the desiccant relates to the equilibrium moisture content, AND THE TEMPERATURE, of their environment. There are of course other levels to judge desiccants and this is not really about desiccants but one (meaning me) could not discount the relationships to equilibrium relative humidity, percent moisture content and temperature.

I started studying isotherms of various products, compounds, elements… what ever you want to label hygroscopic things. I began to move from a faith where I compared everything to water vapor and assumed that all hygroscopic “things” behaved like water vapor. The comparison of all things hygroscopic to that of water vapor a major error. Hygroscopic things are not water vapor. This is the most common error I find when discussing this topic. Everyone wants to talk about water vapor as the final arbiter of percentage water content. The difference between others and myself on this topic is that I have made the discovery that not all things hygroscopic behave like water vapor. This seems simple. But all people want to argue water vapor when in fact you need to discuss the hygroscopic material as well as water vapor. This is a real tough hurdle for many to make. Tobacco is tobacco. Tobacco is not water vapor!

I began to wonder if there was evidence out there to support my empirical observation of lowering my temperature and getting wetter cigars. I tested and tested and tested again! I got the same result! It just did not make sense to me, not as long as I believed in the basis of absolute humidity and the similarity of all hygroscopic materials to water vapor.

I began to move away from thinking about water and more to thinking about tobacco and other hygroscopic substances and this is where I broke though.

If you look closely at the graph above you will notice something. You will notice the exact opposite of what is logical if you are moored to a belief around absolute humidity. As the temperature drops you know that rH increases in a sealed vessel. If you lower the humidity to the previous rH, then you must physically remove water from the system. It is logical then that as you reduce temperature, keeping rH constant that cigar percent moisture content should go down. Yet, this was contrary to what I was noticing empirically and it really bugged me. I knew that there had to be an answer in the tobacco isotherm.

If you look at the graph again you will see it. You will see it plain as day. If you lower your temperature and keep your humidity constant, you actually get wetter, not dryer cigars!

I guess I don’t need to write that paper on rH anymore.

Cheers! -Piggy

Edited by Piggy... I screwed up some up moves with down moves... All correct now, I think! Cheers.