Common Cigar Problems: Tunnelling, Canoeing, Mould and the Beetle

Most cigar problems are preventable. A few are unfixable. Knowing the difference will save you cigars, money and frustration. Here are the four most common issues we get asked about, with practical solutions.

1. Tunnelling

What it is: The cigar burns down the middle while the outer wrapper stays largely intact, leaving a hollow tunnel. The draw becomes hot and the flavour turns bitter.

What causes it: Almost always an uneven light. If you didn't toast the foot evenly at the start, one part of the filler caught faster than the rest. Once that happens, the slower-burning side never catches up.

How to fix it: Touch up the cooler side with your lighter. Hold the flame to the slow-burning wrapper for a few seconds while you draw gently. The burn line should re-balance. Read our full guide on how to light a cigar properly if this happens to you regularly — it's almost always a lighting technique problem.

2. Canoeing

What it is: The cigar burns unevenly along its length, with one side of the wrapper burning faster than the other. The remaining 'wing' looks like a canoe profile.

What causes it: Usually one of three things — uneven humidity (one side of the cigar slightly drier than the other), uneven lighting, or smoking too fast and tilting the cigar.

How to fix it: Same as tunnelling. Touch up the slower side. To prevent it: rotate the cigar in your mouth occasionally as you smoke. Store cigars on their sides in the humidor, not stacked vertically — uniform horizontal storage gives more even humidification (see our storage guide).

3. Mould

What it is: Fuzzy growth on the wrapper. Usually blue, green or white. Different from plume (or 'bloom') — a fine white crystalline dust that is actually a sign of properly ageing tobacco, harmless and brushes off.

How to tell them apart:

• Plume: dry, crystalline, brushes off cleanly, no stain underneath. Smells of nothing in particular.
• Mould: fuzzy or stringy, comes off with smearing, leaves a stain or pitted mark on the wrapper. Smells musty.

What causes mould: Humidity above 75%, often combined with temperature above 22°C. Stagnant air. Cigars touching the inside of a wet humidifier.

What to do: Inspect the rest of the humidor immediately. Any visibly mouldy cigar is gone — throw it out. Cigars adjacent to it should be inspected carefully; minor surface contact may be salvageable with a soft brush. Wipe down the humidor interior with a cloth dampened with distilled water (never alcohol or soap). Recalibrate humidity downward to 65–68%. Boveda packs are particularly useful here as they self-regulate (see our Boveda range).

4. The tobacco beetle

What it is: Lasioderma serricorne, a small reddish-brown beetle whose larvae feed on tobacco. The most feared problem in cigar storage, because by the time you see it, it's already a disaster.

What to look for: Tiny perfectly round holes — about 1mm — appearing in the wrappers of cigars in your humidor. Sometimes a fine brown dust at the bottom of a box.

What causes it: Beetle eggs are present in most tobacco leaf at very low levels. Reputable manufacturers freeze finished cigars to kill any eggs before shipment, but eggs can survive in rare cases. Sustained temperatures above 22°C combined with high humidity hatch them.

What to do: The moment you spot a hole, freeze the entire humidor contents. Seal cigars in plastic bags (push out all air), place in the freezer for 72 hours, then transfer to the refrigerator for 24 hours to ease the temperature transition, then back to the humidor. Yes, freezing premium cigars feels wrong; yes, it is the standard industry response and does not damage the cigars when done correctly. Better than losing the entire humidor.

The simple prevention plan

Most of these problems share a single root cause: bad storage. Keep your humidor at 65–68% RH and below 21°C, use a calibrated hygrometer, rotate stock occasionally, don't pack cigars too tight. Read our storage guide for the full discipline; the cigars you save will pay for the effort many times over.