On Easter morning, the speaker does something ordinary and a little violent: he stamps on a packet of ale yeast to burst the nutrients inside. Within hours the envelope puffs up, and the poem compares it to a sheep's stomach, filled with "afflatus," an old word for inspiration or divine breath. The yeast, in other words, has been resurrected, and the Easter setting makes that idea feel both playful and sincere.
In the second part the speaker looks ahead. He will feed the yeast malt, honey, and bitter herbs, and it will turn them into beer. The bitter herbs quietly recall religious ritual meals. At the end, the dead yeast cells become "empty tombs" settling at the bottom of the bottle's "brown sea." The mood is quietly reverent but humorous, finding something sacred in a kitchen task. Life, death, and renewal all happen in a small, humble place.