A process for predicting the potential for persistence of agrochemical residue levels in beer has been developed. For this, we first developed analytical methods for determining the agrochemical residues in beer, wort, and various by-products during the brewing processes. Second, various types of agrochemicals were spiked during the mashing, wort boiling, or fermentation processes and the residues in the product and in the by-product were determined with the developed method. Agrochemicals added were representative of the typical chemical groups of agrochemicals for which maximum residual levels in barley or hops are regulated by Japanese official law. Third, the potential for the carryover of agrochemical residues into wort and beer was investigated based on their chemical properties such as thermostability, chemical reactivity, and oil/water solubility (which was expressed as log Pow values). It was found that the carryover of agrochemical residues into wort and beer depended on their log Pow values. The carryover percentages into wort or beer of glyphosate (organophosphorus herbicide) having the lowest log Pow value were more than 90% of the amount added to each process. On the other hand, most of the agrochemicals having a high log Pow value, such as pyrethroid pesticides, were detected in the fractions of the spent grains and spent hops. Some amounts of the added agrochemicals were lost during the wort boiling process. On the other hand, no significant reduction was observed during the fermentation process. None of the agrochemicals spiked in the hop pellets were detected in beer because of the loss during boiling and fermentation, though the levels of the spiked agrochemicals were high enough to be detected in beer if no loss of the spiked agrochemicals had occurred. From these results, the process for predicting the potential for the carryover of agrochemical residues in malt or hops into beer on a laboratory scale was proposed, in that the log Pow values of a agrochemical was effectively used as the primary indicator.