This is a discussion on What causes a wrapper to split?? within the General Cigar Discussion forums, part of the The Cigar Lounges at Puff category; I had a great cigar lastnight, except the wrapper split. As I smoked it I could not only see, but ...
Humidity instability is the usual cause of wrapper splits.
If the cigar gets too dry the leaf gets brittle and cracks very easily.
High humidity can also lead to splits. As the filler tobacco gets too moist it will swell and put pressure on the wrapper and binder that can lead to it splitting.
Certain wrappers are more prone to splitting than others, and can split even if the cigar is kept under consistant proper humidity conditions. Cameroon wrapper is extremely fragile and splits much more easily than other leaves.
If you aren't already using silica beads to control humidity in your humidor, do so. If the cigar was smoked from a shop check the hygrometer in the store next time you are in there. Avoid buying cigars that look swollen at the foot, this is a sign of overhumidification.
My experience tell sme that splitting is most often related to uneven humdity through out the cigar. With uneven humidity, the layers of the cigar to not expand at the same rate or have the same level of elasticity.
cigars kept in a humidor with a constant RH can still have this problem if they are not rotated or turned for a long period of time.
One little trick that I have adopted is to put those little stir straws that you get in a bar between the layers of cigars in the humidors. This allows air and humidity a better chance to move between the cigars.
[SIZE="2"]Did you hear that boy?
Keep your pride tied![/SIZE][SIZE="1"]......Hidalgo[/SIZE]
It looks like you've got some solid answers so far but let me throw in my .
A few years ago, I took a CAO Brazilia from my home at 1500' in a semi coastal area (humid) to an area that we vacation at (9-10,000ft and very dry). I took the cigar out of the bag that it was in and left it on the table while I made dinner. When I went to smoke the cigar, the wrapper unraveled and I couldn't stop it. It completely came apart before I could smoke it.
I'd have to agree with the rapid RH change theory.
Here's something I wrote some time ago in response to a fellow whose cigar split lengthwise while he was smoking in a room that was heated by a radiant (IR) heater. I would like to hear what other folks have experienced as far as the thickness of the wrapper of cigars that have unravelled or cracked.
1. Moistened tobacco is more elastic than dry tobacco. More precisely, moisture in the wrapper will shift the yield/fracture point on the stress-strain curve. Mechanical engineers, please chime in. The effect can be illustrated by the following example: A dry piece of uncooked lasagna noodle is quite brittle, especially in tension (meaning pulling the noodle from its two ends). However, soak it overnight (you don't even need to cook it) and it will swell with water and become much more flexible. You will be able to grab the ends and stretch it slightly whereas doing so with the dry noodle would cause it to fracture well before the same degree of stretching is achieved. This is the key and leads to the second point...
2. A dry room will quickly drop the equilibrium moisture level in tobacco. It's commonly quoted that "wet" cigars contain about 14% humidity. This level is pretty low already and as the wrapper is so thin and light, very little needs to be driven from the leaf, (probably on the order of mere milligrams) to push it into the range where it will become brittle. Especially problematic is the fact that you were using a radiant heater. If the heater was directed toward the smokers, then the infrared radiation will directly warm and more rapidly dry off the wrapper, and unless you roll you cigar as you smoke it, one side will be preferentially affected. This effect spells the beginning of trouble and part two of the one-two punch is as follows...
3. Warm tobacco expands. More to the point, warm tobacco will also absorb more moisture as it expands. As is the case with most any material, making tobacco warmer will cause it to expand. However, in a cigar, the situation is slightly more complex with this complexity potentially resulting in a greater risk of splitting. The reason is this: Not only will tobacco expand slightly in thickness and across the flat dimension, the tobacco is stacked. The net result of this stacking is to add up stresses which result from expanding leaves that are physically in contact with each other. Try to visualize it this way:
You have a stack of 100 sheets of paper. Now, let's pretend that pushing the top sheet 1mm to the right hand side simulates the expansion of that piece of leaf. Ok, 1mm is not a lot. Now, push the second sheet 1mm. Then the third and so on. After 25 sheets have been pushed, the top sheet will be 1 full inch out from the stack. Of course, in the real case the additive effect is not always in the same direction nor are all filler leaves aligned and in perfect and intimate contact with each other. If this were true, the majority of all cigars would split under any condition.
Now, as for how the cigar split.
4. When hollow pipes fail, they split lengthwise. Hollow cylinders that are pressurized experience hoop stress. That is, because of the nature of stresses on a hollow shell, the greatest stress is in the circumferential direction. That's why when tanks and such fail, they will always appear to split from top to bottom. Rarely, if ever, do they split into a top half and a bottom half. Hoop stress failure is also the operative mechanism in the unfortunate medical condition, aortic dissection (such as in Marfan Syndrome). You could consider the wrapper and binder of a cigar as concentric shells subject to this hoop stress as the filler expands. (note: sorry for the slightly techie explanation)
So, the bottom line is as follows:
1. Taking a cigar from a humid atmosphere to a dry one will immediately begin the drying out process.
2. Drying out is exacerbated by forced air or radiant heating in the direction of the smoker.
3. Thin wrappers will lose humidity relatively more rapidly than thicker wrappers and thus lapse into brittleness.
4. When the wrapper fails, it will either crack and unravel, or in cases where the stresses have substantially built up, split up a good length of the cigar.
There is good information in 3x5card's post. I would add that wrappers are obviously on the outside of the cigar and are the first leaves affected by humidity changes. Couple this with the fact that wrappers are stretched tight around the filler which is compressed and not stretched like the wrapper, there can be a lot of pressure exerted on the wrapper due to humidity issues.
[SIZE="2"] A cigar board is only as good as it's leader[/SIZE]
Yep, any drastic change in humidity will do it, and I think a rapid change in temperature will cause the same...
Like someone posted the other night, he went outside to smoke and the humidity outside was almost 100% (it began to pour rain) and the stick split if I remember the thread correctly.
I call this "humidity shock" this is when the cigar has a drastic change in humidity and or temp. It happens alot during shipping. Other factors mentioned in this thread can lead to split wrappers. RJT