Abstract: Hydroxymethylfurfural is made from an aqueous hexose sugar solution, especially from a high fructose corn syrup product. By rapidly heating the sugar solution to the elevated temperatures involved as well as rapidly cooling the resultant product mixture, a limited per-pass conversion to HMF is obtained; correspondingly, however, the overall exposure of the HMF that is formed to acidic, elevated temperature conditions is also limited, so that byproducts are reduced. Separation and recovery of the products is simplified, and levels of HMF and other hexose dehydration products known to inhibit ethanol production by fermentation are reduced in the residual sugars product, to an extent whereby the residual sugars product is suited to be directly fermented to ethanol or for other uses.