  Quantifying the composition of the material in protoplanetary disks is
paramount to determining the potential for exoplanetary systems to produce and
support habitable environments. A key complex organic molecule (COM) to detect
is methanol (CH3OH). CH3OH primarily forms at low temperatures via the
hydrogenation of CO ice on the surface of icy dust grains and is a necessary
basis for the formation of more complex species like amino acids and proteins.
We report the detection of CH3OH in a disk around a young, luminous A-type star
HD100546. This disk is warm and therefore does not host a significant CO ice
reservoir. We argue that the CH3OH cannot form in situ, and hence, this disk
has likely inherited COMs rich ice from an earlier cold dark cloud phase. This
is strong evidence that at least some of the organic material survives the disk
formation process and can then be incorporated into forming planets, moons and
comets. Therefore, crucial pre-biotic chemical evolution already takes place in
dark star-forming clouds.
