From Kook Science

Alphitomancy (from the Greek: ἄλφῐτον, álphiton ["barley meal"] + μαντεία, manteia ["divination, soothsaying"]), or krithomancy (Greek: χριθή, krithí ["barley"]), is a method of divination conducted by use of barley, either in the form of meal or flour (including prepared foods made using them) in an alphitomantic operation, or as whole grains in a krithomantic operation.

One archaic form of this divination was reputedly a trial by ordeal, whereby an accused person would be fed barley cake or bread and would be found guilty if they experienced any digestive upset.