Historical clue formulations

• Purple drink ingredient at a boba tea shop — 2026-08-14
• Purple yam in Filipino desserts — 2026-08-09
• Purple yam used to flavor desserts — 2026-01-26
• Purple yam in Philippine cuisine — 2025-04-27
• Purple yam common in Filipino cooking — 2024-12-30
• Bright purple yam used to flavor desserts — 2023-06-17