  Using a new horizontal flux growth technique to produce high quality crystals
of the unconventional superconductor YFe$_2$Ge$_2$ has led to a seven-fold
reduction in disorder scattering, resulting in mm-sized crystals with residual
resistivities $\simeq \SI{0.45}{\micro\ohm\centi\meter}$, resistivity ratios
$\simeq 430$ and sharp superconducting heat capacity anomalies. This enables
searching multi-probe experiments investigating the normal and superconducting
states of YFe$_2$Ge$_2$. Low temperature heat capacity measurements suggest a
significant residual Sommerfeld coefficient, consistent with in-gap states
induced by residual disorder as predicted for a sign-changing order parameter.
