A Cigar Is Porous, But How Porous?

Cut a premium cigar across the middle.

You see tobacco almost everywhere.

Yet when you draw through the cigar, air travels from one end to the other.

So where exactly is the air going?

Through the spaces the tobacco leaves did not occupy.

A long-filler cigar is not a solid cylinder.

It is a complex porous structure containing leaves, folds, veins, interfaces and thousands of interconnected voids.

And that brings us to a more interesting question than draw resistance:

How permeable is the cigar?

What You'll Learn

• The difference between porosity and permeability.
• Where airflow pathways exist inside long filler.
• Why having empty space is not enough.
• How local compression can redirect airflow.
• Why moisture may change the internal flow network.
• How CT imaging and pressure measurements could map cigar permeability.

A Cigar Is Tobacco Plus Empty Space

This sounds obvious until you think about the geometry.

The filler leaves do not occupy every cubic millimeter inside the binder.

Between folds and neighboring leaves are small spaces.

Some run longitudinally.

Some intersect.

Some narrow.

Some terminate.

Together they form a three-dimensional network through which gas can move.

Without connected void space, there would be no usable draw.

Porosity Is Not the Same as Permeability

This distinction is fundamental.

POROSITY describes how much of a material's volume consists of void space.

PERMEABILITY describes how readily fluid or gas can move through its connected pore structure.

Those are not interchangeable.

Imagine two cigars with exactly the same percentage of empty space.

In Cigar A, the spaces connect from foot to head.

In Cigar B, many spaces terminate inside the bunch.

Their porosity could be similar.

Their permeability could be very different.

A Parking Garage Is a Useful Analogy

Imagine two parking garages containing the same amount of empty floor area.

One has connected ramps and exits.

The other has walls dividing much of that empty space into isolated rooms.

Same amount of empty space.

Completely different ability to move through it.

A cigar presents a related problem.

The question is not only how much empty space exists. It is whether that space connects.

Long Filler Creates an Irregular Network

Premium long-filler tobacco is not ground material packed uniformly into a tube.

Leaves retain substantial longitudinal structure and are folded and arranged into a bunch.

This creates elongated spaces between neighboring tobacco surfaces.

Some become useful airflow channels.

Others connect only indirectly.

Some can become narrowed by compression.

That is why the internal structure should be imagined as:

ANISOTROPIC + IRREGULAR + INTERCONNECTED

rather than a bundle of identical drinking straws.

Air Does Not Need One Perfect Tunnel

This is another important misconception.

A cigar does not require one continuous empty hole running from foot to head.

Air can divide among many small pathways.

A pathway can disappear.

The flow can move around a dense region and enter neighboring voids.

Then multiple paths can merge again.

The cigar behaves more like a porous network than a pipe.

Now Compress One Small Region

Imagine that one side of the bunch becomes locally denser.

The cigar's external diameter may remain unchanged.

But inside:

VOID SIZE ↓

LOCAL CONNECTIVITY MAY CHANGE

FLOW RESISTANCE MAY ↑

Air can then redistribute toward alternative pathways.

This explains why a cigar can contain a localized dense region without becoming completely plugged.

Overall Draw Can Hide Local Problems

Suppose a draw-testing machine reports an acceptable pressure drop.

It would be tempting to conclude that the internal structure is perfect.

Not necessarily.

Imagine half the original pathways becoming restricted while the remaining pathways still transmit enough air.

The whole-cigar measurement may remain acceptable.

Yet internally, flow has become much less uniform.

One pressure-drop number compresses an entire three-dimensional network into one measurement.

This Is Where Permeability Goes Beyond Draw Resistance

Draw resistance asks:

HOW MUCH PRESSURE DIFFERENCE IS REQUIRED TO PRODUCE A DEFINED FLOW?

Permeability asks something deeper:

WHAT PROPERTY OF THE INTERNAL STRUCTURE ALLOWS THAT FLOW TO OCCUR?

The two are related.

They are not identical.

The Physics Has a Useful Starting Point

Flow through porous materials is often described using Darcy-type relationships.

In simplified form:

FLOW ∝ PERMEABILITY × PRESSURE DIFFERENCE × AREA ÷ LENGTH

with gas viscosity and other conditions also affecting the relationship.

This gives us an important lesson.

A raw pressure-drop reading alone is not an intrinsic description of the filler.

Cigar length, cross-sectional area, flow rate and testing conditions matter too.

Two Different Vitolas Complicate the Comparison

Consider a 46-ring cigar and a 60-ring cigar.

They have different cross-sectional areas.

They may also have different filler architecture.

So simply saying:

“THIS CIGAR HAS A LOWER PRESSURE DROP”

does not automatically prove that its tobacco network is intrinsically more permeable.

Geometry must be considered.

The Current El Septimo Range Makes This Interesting

The current El Septimo cigar collection spans substantially different geometries, including Japan Nigori at 6 × 46, Doble Gran Reserva at 6 × 52, Bomba Orange at 6½ × 60 and France Bordeaux at 6 × 60.

The broader El Septimo range currently extends to formats such as Fabuloso Dark Ruby at 6¼ × 70.

Those differences make diameter an important experimental variable rather than something to ignore.

Moisture Adds Another Dimension

Tobacco is hygroscopic.

Its physical properties change as it absorbs and releases moisture.

That raises an important permeability question:

Does changing tobacco moisture alter the dimensions, flexibility or compression of the internal pathways enough to measurably change gas flow?

It is plausible.

But the direction and magnitude should be measured rather than assumed.

Do Not Simply Say “Wetter Means Tighter”

That explanation is attractive because it sounds intuitive.

But a cigar contains many interacting structures.

Moisture can affect:

• Leaf dimensions
• Mechanical flexibility
• Compression behavior
• Contact between neighboring leaves
• Local void geometry

Whether those changes create a meaningful whole-cigar permeability difference depends on the architecture.

Measure the network.

The Experiment: Same Cigar, Three Moisture Conditions

Take matched cigars from the same production lot.

Condition groups at three controlled moisture states.

Do not begin by predicting which group will have the easiest draw.

Measure:

CT Imaging Is Where This Gets Fascinating

A pressure test tells us what the cigar does.

Imaging can begin showing us why.

High-resolution X-ray CT could reconstruct the bunch without cutting it open.

Separate approximately:

TOBACCO MATERIAL

from

VOID SPACE

Then reconstruct that void space in three dimensions.

Now Measure Connectivity

Once the void network is reconstructed, ask:

• How much void volume exists?
• How much is connected from foot to head?
• Where are the narrowest constrictions?
• Are there isolated voids?
• Does one side contain more connected pathways?
• How indirect are those pathways?

This moves cigar construction from visual inspection toward porous-media engineering.

Tortuosity May Matter as Much as Empty Space

Imagine a straight pathway from foot to head.

Now imagine another pathway that repeatedly bends around leaves, stems and compressed regions.

Both connect the same two ends.

But the second route is longer and more indirect.

Porous-media science describes this concept using tortuosity.

Conceptually:

STRAIGHTER PATH → LOWER TORTUOSITY

MORE INDIRECT PATH → HIGHER TORTUOSITY

Whether a particular cigar's measured resistance can be attributed to tortuosity requires actual imaging and flow analysis.

Leaf Orientation Should Matter Too

Long-filler leaves preserve substantial longitudinal structure.

That means their orientation may influence how voids connect along the cigar's length.

This helps explain why bunching is an architectural skill.

The buncher is not merely achieving the correct tobacco mass.

The buncher is creating a three-dimensional arrangement that must preserve workable airflow.

Same Weight Does Not Mean Same Permeability

Take two cigars containing exactly the same tobacco mass.

Cigar A distributes that mass relatively evenly.

Cigar B contains several locally compressed regions.

Total mass:

SAME

External dimensions:

SAME

Internal network:

DIFFERENT

Therefore, mass alone cannot tell us how easily gas can cross the cigar.

Same Porosity Might Not Mean Same Permeability Either

This is the deeper lesson.

Imagine both cigars contain 25 percent void space.

That number is illustrative, not a measured cigar value.

In one cigar, nearly all those voids connect longitudinally.

In the other, much of the space is isolated or connected through severe constrictions.

Same porosity. Different permeability.

The Ultimate Experiment

Take 20 nominally identical cigars.

Before smoking, measure:

MASS | LENGTH | DIAMETER | PRESSURE DROP | AIRFLOW

Then CT-scan every cigar.

Calculate:

VOID FRACTION | CONNECTIVITY | TORTUOSITY | LOCAL DENSITY | CONSTRICTION SIZE

Next, blind-test their cold draws.

Finally, smoke them under controlled conditions and record:

BURN RATE | BURN DEVIATION | RELIGHTS | TOUCH-UPS | SMOKE OUTPUT

Now ask:

Which internal structural measurement best predicts how the cigar actually performs?

And the Answer Might Not Be Porosity

Perhaps total void fraction predicts draw.

Perhaps it does not.

Perhaps the narrowest constriction dominates.

Perhaps longitudinal connectivity matters more.

Perhaps local density variability explains more than average density.

Or perhaps several variables interact.

That uncertainty is exactly what makes the experiment worthwhile.

Then Light the Cigar

So far, everything has described the cold cigar.

Once combustion begins, the system changes.

The cigar becomes shorter.

Tobacco heats.

Moisture moves.

Smoke and aerosol travel through the remaining filler.

The upstream boundary becomes a hot combustion zone rather than room air.

So:

COLD PERMEABILITY ≠ COMPLETE DESCRIPTION OF SMOKING AIRFLOW

Could Permeability Change During the Smoke?

That is an excellent second experiment.

Measure pressure behavior at:

COLD → FIRST THIRD → MIDDLE THIRD → FINAL THIRD

Then compare it with cigar length and thermal state.

If the apparent flow resistance changes, ask whether the cause is simply decreasing length or whether the remaining tobacco network is changing too.

Why This Matters for Premium Construction

El Septimo Dubai's current cigar portfolio is described as hand-rolled using long-filler tobaccos.

That construction makes the internal architecture particularly interesting because intact leaves must be arranged so flavor, combustion and airflow coexist inside one cylinder.

Explore the El Septimo cigar collection or compare formats in the premium cigar collection. The latter currently includes formats from the 6 × 52 Doble Gran Reserva through 60-ring cigars such as Kolosso Amethyst and Bomba Orange.

Final Thoughts

A cigar looks full.

But airflow depends on what is missing.

The tiny spaces between leaves create the hidden network that connects foot to head.

Yet the amount of empty space tells only part of the story.

The spaces must connect.

They must avoid severe constrictions.

They must survive compression.

And they must continue functioning as moisture, temperature and cigar length change.

POROSITY asks: How much empty space is there?

PERMEABILITY asks: Can air actually get through it?

That difference takes us from describing a cigar's draw to understanding its internal engineering.

Frequently Asked Questions

Is a cigar porous?
Yes. A cigar contains interconnected void spaces between filler leaves through which air and smoke can travel. It is better understood as a porous tobacco network than as either a solid cylinder or an empty tube.

What is the difference between cigar porosity and permeability?
Porosity describes the amount of void space. Permeability describes how readily gas can move through the connected void network. A cigar can contain substantial void space without all of that space contributing effectively to longitudinal airflow.

Is permeability the same as draw resistance?
No. Draw resistance is an observable pressure-flow behavior of the cigar under specified test conditions. Permeability describes an underlying transport property of its porous structure and must be interpreted together with geometry and test conditions.

Can two cigars with the same amount of tobacco have different draws?
Yes. Identical mass and external dimensions do not guarantee identical internal density, void connectivity, constrictions or pathway geometry.

Can moisture change cigar permeability?
Potentially. Moisture changes tobacco's physical and mechanical behavior and could alter contact, compression and void geometry. The magnitude and direction should be measured rather than assumed.

For adults 21+. Please enjoy responsibly.