  The first detection of gas-phase methanol in a protoplanetary disk (TW Hya)
is presented. In addition to being one of the largest molecules detected in
disks to date, methanol is also the first disk organic molecule with an
unambiguous ice chemistry origin. The stacked methanol emission, as observed
with ALMA, is spectrally resolved and detected across six velocity channels
($>3 \sigma$), reaching a peak signal-to-noise of $5.5\sigma$, with the
kinematic pattern expected for TW~Hya. Using an appropriate disk model, a
fractional abundance of $3\times 10^{-12} - 4 \times 10^{-11}$ (with respect to
H$_2$) reproduces the stacked line profile and channel maps, with the favoured
abundance dependent upon the assumed vertical location (midplane versus
molecular layer). The peak emission is offset from the source position
suggesting that the methanol emission has a ring-like morphology: the analysis
here suggests it peaks at $\approx 30$~AU reaching a column density $\approx
3-6\times10^{12}$~cm$^{-2}$. In the case of TW Hya, the larger (up to mm-sized)
grains, residing in the inner 50~AU, may thus host the bulk of the disk ice
reservoir. The successful detection of cold gas-phase methanol in a
protoplanetary disk implies that the products of ice chemistry can be explored
in disks, opening a window to studying complex organic chemistry during
planetary system formation.
