Preston Farm Zinfandel, Dry Creek Valley, California, USA

Provenance tiers

• Verified (first-party)Confirmed directly by the tenant. The highest-confidence, first-party record.
• Tech sheetProducer-published technical document (PDF or web). High confidence, directly from source.
• Producer siteScraped from the producer's public website. Reliable but not formally verified.
• Importer siteScraped from the importer's catalog or website. One step removed from the producer.
• COLA / government recordTTB Certificate of Label Approval or other official registry. Authoritative but limited in scope.
• Inferred (LLM research)Filled by language-model inference from multiple public sources. Useful, but verify before acting.
• Manual / operatorEntered or curated by a WineGraph operator. Authoritative within its scope; check the ref.