Live Indigo Dyeing: Working with Fermentation, Fruit Sugar & Mineral Vats

After spending Indigo Week building three very different indigo vats together, it was finally time to begin dyeing.

In this live session, we moved from theory into practice, exploring what actually happens once a vat is ready and how small decisions throughout the dyeing process influence the final colour.

Using the fermentation vat, organic fruit sugar vat and mineral vat, we compared how each system behaves and discussed the strengths and limitations of each approach. While all three vats are capable of producing beautiful blues, each has its own rhythm, maintenance requirements and relationship with different fibre types.

One of the central themes of the session was colour development. Indigo is unique in that depth of shade is generally achieved through multiple dips rather than longer immersion times. Participants were able to see how colour builds gradually and how oxidation between dips contributes to the final result.

We also looked at textile preparation and finishing. Questions around wetting out, scouring, fibre selection and post-dye handling generated valuable discussion, particularly around silk, wool and cellulose fibres. These practical details often make the difference between a successful result and a disappointing one.

Another important topic was crocking — the transfer of excess indigo pigment from the surface of a textile. Understanding why crocking occurs and how proper rinsing, oxidation and finishing can reduce it is an essential part of working successfully with indigo.

The session concluded with an extended question-and-answer discussion covering vat pH, fibre suitability, overdyeing, colour fastness, shibori techniques, recovering indigo from rinse water and long-term vat maintenance.

Indigo dyeing is often presented as a simple process of dipping cloth into a blue vat. In reality, it is a conversation between fibre, chemistry, time and observation. The more we work with these living systems, the more we learn to recognise their individual character.

Indigo Week is an annual event within the Academy, returning each year with a different focus. In 2027, we will be exploring woad in depth. All recordings from Indigo Week 2026, along with recipe PDFs and supporting materials, are available at any time to Full Membership members in the Resource Library.

The recording is now available in the Resource Library for Full Membership members.

We have one more live session 24/06/2026: Troubleshooting Your Indigo Vat. This final gathering will focus entirely on questions, problem-solving, and helping you keep your vats healthy and productive long after Indigo Week has finished.

Everyone is warmly welcome to join. You can access the session by becoming a member here:
https://appleoakfibreworks.com/collections/academy-membership/products/1-year-academy-membership-br-natural-dyers-growers-academy

Or purchase membership directly through the Academy:
https://the-natural-dyers-academy.mn.co/plans/1962109?bundle_token=03b347af518e93063c459946be9225ac&utm_source=manual