Spirulina starter culture: where to get it and what to look for

DRAFT, do not publish. Briefing from the content plan dated 09/14/2026, item 04.

• Target keyword: buy spirulina starter culture, living spirulina culture
• Intent: transactional
• Reason: Below the largest German DIY guide, there are over 144 comments requesting living starter cultures. Documented, unmet demand.
• Must include: What defines a living culture, transport, how to recognize if it has survived shipping, renewal interval. Link to the single product Spirulina culture.