A container comprising: a base portion configured to support the container in an upright orientation relative to a support surface and wherein the base portion defines an at least substantially octagonal perimeter; a spout positioned opposite the base portion and oriented such that a centerline of the spout is aligned with a centerline of the base portion; a plurality of alternating long sidewalls and short sidewalls extending between the perimeter of the base portion and the spout and having curved vertical transitions joining adjacent sidewalls, wherein the curved vertical transitions extend between the base portion and the spout, the plurality of alternating long sidewalls and short sidewalls collectively defining: a vertical portion extending away from the base portion; a downward sloping planar top portion extending away from the spout and toward the vertical portion; a gradually curved transition region extending between the vertical portion and the downward sloping planar top portion; and a strength protrusion surrounding the spout and defined within the downward sloping planar top portion; and vertical grooves (221,222) defined within at least one of the long sidewalls or the short sidewalls and extending within the vertical portion and the gradually curved transition region; characterised in that the vertical grooves comprise at least one first vertical groove having a first length and at least one second vertical groove having a second length, wherein the second length is longer than the first length. a base portion configured to support the container in an upright orientation relative to a support surface and wherein the base portion defines an at least substantially octagonal perimeter; a spout positioned opposite the base portion and oriented such that a centerline of the spout is aligned with a centerline of the base portion; a plurality of alternating long sidewalls and short sidewalls extending between the perimeter of the base portion and the spout and having curved vertical transitions joining adjacent sidewalls, wherein the curved vertical transitions extend between the base portion and the spout, the plurality of alternating long sidewalls and short sidewalls collectively defining: a vertical portion extending away from the base portion; a downward sloping planar top portion extending away from the spout and toward the vertical portion; a gradually curved transition region extending between the vertical portion and the downward sloping planar top portion; and a vertical portion extending away from the base portion; a downward sloping planar top portion extending away from the spout and toward the vertical portion; a gradually curved transition region extending between the vertical portion and the downward sloping planar top portion; and a strength protrusion surrounding the spout and defined within the downward sloping planar top portion; and vertical grooves (221,222) defined within at least one of the long sidewalls or the short sidewalls and extending within the vertical portion and the gradually curved transition region; characterised in that the vertical grooves comprise at least one first vertical groove having a first length and at least one second vertical groove having a second length, wherein the second length is longer than the first length.