Described are methods for preparing virosomes comprising the steps of: (a) providing an enveloped virus, and optionally inactivating the virus; (b) solubilizing the viral envelopes in a first solubilizing agent; (c) pre-solubilizing exogenous components in a second solubilizing agent; (d) adding the pre-solubilized exogenous components to the solubilized viral envelopes; and (e) reconstituting virosomal membranes by removing the solubilizing agent. According to the disclosure, the viral envelopes and the exogenous components are (pre-)solubilized at a temperature below 33° C.