How much of this is variation between farms and how much is variations between batches? If the taste of every batch (a given farm's crop in a given season) wer

How much of this is variation between farms and how much is variations between batches? If the taste of every batch (a given farm's crop in a given season) were effectively random we would also see large variations from farm to farm. The theory are suggesting is that a given farm (or a given country, or a given brand) is long-term consistent and different from one another, but a double blind difference taste test at low N would be insufficient; You would need to test/quantify other forms of variation as well.