The method for preparing high grade gelatin with a specific methionine content and with reduced methionine variability from batch to batch and within a single extraction includes controlling the amount of and variability of oxidant present during processing of bone stock into gelatin. Such controls include control of oxidant concentration and range in process water, control of volume of process water used in gelatin-making process and restriction of the range of gelatin extracts used in the product gelatin. Once the aim level of oxidant has been set, the total range of oxidant around the set point should be less than 220 meq per 100 kg dry bone.