Pure walnut fermented milk and preparation method thereof

The invention relates to the technical field of walnut milk processing, in particular to pure walnut fermented milk and a preparation method thereof. The pure walnut fermented milk provided by the invention comprises the following raw materials: 10-14 parts of walnut kernels; 2.7 to 5.4 parts of a fermentation promoting factor; 0.066 to 0.22 part of an auxiliary material; 0.003 to 0.01 part of a composite strain; the fermentation promoting factor is composed of fructo-oligosaccharide, inulin, polydextrose and a yeast extract, and the mass ratio of the fructo-oligosaccharide to the inulin to the polydextrose to the yeast extract is (8-12): (38-42): (28-32): 1. According to the method disclosed by the invention, the fermentation promoting factors with specific components are added in the fermentation process, so that the walnut milk fermentation and subsequent metabolism acid production of the lactic acid bacteria can be quickly started under the conditions of not adding any fermentation carbon source and not p