Kosmas Sourdough

Sourdough Story

Some sourdoughs in our library carry more than just flavor—they carry history, culture, and deep spiritual meaning. One such example is Sourdough #39, known as Kosmas, a remarkable starter from the Greek town of Amfilochia.

The story of this sourdough is rooted in a centuries-old religious tradition. In the Eastern Orthodox Church, September 14th marks the beginning of the Feast of the Exaltation of the Cross, one of the Twelve Great Feasts of the liturgical year. This solemn celebration, still observed in Amfilochia today, includes ancient rituals that blend faith, nature, and community.

On the eve of the feast, women in the village bring fresh basil leaves or flowers to the church. The basil is laid on the altar, forming a fragrant bed for the cross, which remains on display throughout the eight days of the celebration. Each time the faithful enter or leave the church, they venerate the basil-covered cross. On the final day, the priest and deacon light incense and return the cross to the sanctuary in a moving ceremony.

But the most fascinating part comes at the end: the priest immerses the cross in a bowl of water, infusing it with the natural micro-organisms from the basil. This holy water is then distributed to the women, who take it home not only to bless their homes—but also to start a sourdough.

This sacred water becomes the foundation for the bread they bake throughout the year. It’s a beautiful example of how faith and fermentation come together in everyday life. The Kosmas sourdough is more than a starter—it’s a living symbol of tradition, community, and reverence.

We’re honored to have this sourdough as part of the Puratos Sourdough Library, where it holds a special place as entry #39. To share its story, we traveled to Tokyo to film a new episode in our Quest for Sourdough series.

This sourdough reminds us that bread is never just bread. It’s a reflection of the people who make it, the rituals they follow, and the stories they pass down. We’re proud to preserve and celebrate that heritage.