Quintuplet Condensation in the Skyrmionic Insulator <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"> <mml:mrow> <mml:msub> <mml:mrow> <mml:mi>Cu</mml:mi> </mml:mrow> <mml:mrow> <mml:mn>2</mml:mn> </mml:mrow> </mml:msub> </mm

We report ultrahigh magnetic field Faraday rotation results on the chiral helimagnet Cu_{2}OSeO_{3}, the first Mott insulator showing skyrmion lattice phases and a linear magnetoelectric effect. Between 180 and 300 T, we find signatures of a Bose-Einstein condensation of magnons, which can be described as a canted XY ferrimagnet. Because of the magnetoelectric coupling, the transverse magnetic order of the individual Cu^{2+} spins is accompanied by a characteristic domelike electric polarization which is crucial for the observation of the condensate via the Faraday rotation effect.