The stage in which filler leaves are gathered, arranged, and enclosed in the binder to form the cigar's core. Draw, burn, and density are all settled here, before any wrapper is applied.
Why it matters
Most construction defects - plugs, tunneling, uneven burn - originate at the bunch rather than in the wrapper, which is why quality control concentrates on this step.
In context
"The wrapper is fine; the problem is in the bunch."