The present invention describes a process to isomerize industrial hemp derived Cannabidiol (CBD) to a pure Δ8-tetrahydrocannabinol (Δ8-THC) extract. This procedure will produce Δ8-tetrahydrocannabinol that is essentially free from any detectable levels of Δ9-tetrahydrocannabinol (Δ9-THC). Included in this filing are methods and processes to scale the reaction from the lab to process to large scale manufacturing. Additionally, the resulting extract from said methods and processes consists of higher purity than previously reported in the art and greater efficiency compared to prior art.