An aqueous ink for ink jet, the aqueous ink comprising: a pigment; and a resin dispersant for dispersing the pigment, wherein the pigment is impregnated with a compound having a structure in which at least two structures each represented by General Formula are bonded by a glycoside bond: in General Formula , each of R 1 to R 6 is independently a hydrogen atom, a methyl group, a phosphonic acid group, -(CH 2 ) x -OH, -(OCH(CH 3 )) y -COOH, -NH(COCH 2 ) z -H, or -NHCOCH 2 CH(OC 11 H 22 CH 3 )C 10 H 20 CH 3 , and at least one of R 1 and R 2 is a hydroxy group; and each of x and y is independently a number from 0 or more to 6 or less, and z is 0 or 1, wherein a content (ppm) of the compound with which the pigment is impregnated, in terms of mass ratio to a total content (ppm) of the compound in the ink is 90% or more, wherein the compound with which the pigment is impregnated is the compound that remains in a liquid containing the pigment after the compound present in a free state in the ink is removed by ultrafiltration through a hollow fiber membrane having a cutoff molecular weight of 100kDa, wherein the total content (ppm) of the compound in the ink is the sum of the content of the compound with which the pigment is impregnated and the content of the compound present in a free state in the ink, said contents of the compound are measurable as described in the description, and wherein the compound with which the pigment is impregnated is a lipopolysaccharide comprising, as the structure represented by the General formula , N-acetylglucosamine and N-acetylmuramic acid, and further comprising lipid A. a pigment; and a resin dispersant for dispersing the pigment, wherein the pigment is impregnated with a compound having a structure in which at least two structures each represented by General Formula are bonded by a glycoside bond: in General Formula , each of R 1 to R 6 is independently a hydrogen atom, a methyl group, a phosphonic acid group, -(CH 2 ) x -OH, -(OCH(CH 3 )) y -COOH, -NH(COCH 2 ) z -H, or -NHCOCH 2 CH(OC 11 H 22 CH 3 )C 10 H 20 CH 3 , and at least one of R 1 and R 2 is a hydroxy group; and each of x and y is independently a number from 0 or more to 6 or less, and z is 0 or 1, in General Formula , each of R 1 to R 6 is independently a hydrogen atom, a methyl group, a phosphonic acid group, -(CH 2 ) x -OH, -(OCH(CH 3 )) y -COOH, -NH(COCH 2 ) z -H, or -NHCOCH 2 CH(OC 11 H 22 CH 3 )C 10 H 20 CH 3 , and at least one of R 1 and R 2 is a hydroxy group; and each of x and y is independently a number from 0 or more to 6 or less, and z is 0 or 1, wherein a content (ppm) of the compound with which the pigment is impregnated, in terms of mass ratio to a total content (ppm) of the compound in the ink is 90% or more, wherein the compound with which the pigment is impregnated is the compound that remains in a liquid containing the pigment after the compound present in a free state in the ink is removed by ultrafiltration through a hollow fiber membrane having a cutoff molecular weight of 100kDa, wherein the total content (ppm) of the compound in the ink is the sum of the content of the compound with which the pigment is impregnated and the content of the compound present in a free state in the ink, said contents of the compound are measurable as described in the description, and wherein the compound with which the pigment is impregnated is a lipopolysaccharide comprising, as the structure represented by the General formula , N-acetylglucosamine and N-acetylmuramic acid, and further comprising lipid A. <EOS>