In spite of brettanomyces existing worldwide, it is still reasonable to assume that the combination and ratio of brettanomyces and other individual microorganisms within the Payottenland are unique to the local terrior. For example, in 1993, Frank Boon was said to have discovered 86 unique strains that he believed played a significant role in the fermentation at [[Brouwerij_Boon|Boon]]. <ref name=Lambic.digest-9312>Lambic Digest, December 2, 1993, https://192.185.42.233/Lambic_digest/1993/9312.txt</ref>.
However, the naturally occurring yeasts at Boon are significantly different than yeasts occurring at Cantillon, for example. Even the yeasts at an individual location will change over time. Cantillon is now surrounded by buildings, cars, and industry. As cityscapes changes change so does the local terroir. The yeasts of 50 years ago at any location are likely different than the yeasts of today. Even the yeasts and other microflora at other locations around the world have similar characteristics. Studies have shown that yeasts in other regions, such as the Allagash Brewery in Maine, have a similar makeup.<ref name=AWAStudy> Brewhouse-Resident Microbiota Are Responsible for Multi-Stage Fermentation of American Coolship Ale
http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0035507</ref>