Relatively little is known about women's knowledge of natural philosophy in early modern England. Manuscript and printed receipt books show that women, by virtue of their work in the household, were experts in the alchemical processes of sublimation, fermentation, calcination and distillation. The poetry of Hester Pulter (1596–1678) is remarkable for a sophisticated use of terms, images and conceits drawn from alchemy. As such, it provides important evidence of one woman's imaginative and intellectual engagements with the experimental, esoteric and emblematic traditions in alchemy. Paying particular attention to a cycle of poems entitled 'The Circle', I show how Pulter tirelessly worked and reworked alchemical concepts and images, and, just like an alchemist, transformed them into something new.