A method of refining beet juice containing a colorant wherein the beet juice is contacted with an adsorbent composed of a dehydrated solid of a coprecipitated substance formed by insolubilizing metallic compounds in an aqueous solution. The adsorbent contains either a calcium or magnesium compound and also either an aluminum or iron compound. The process is conducted in a temperature range of 40 DEG -100 DEG C.