The DarkSide-20k experiment will use 260,000 silicon photomultipliers (SiPMs) to read out the prompt scintillation light in their liquid argon detector to hunt for dark matter. To account for production yield, nearly 400,000 SiPMs were fabricated at Fondazione Bruno Kessler, followed by a comprehensive wafer-level quality assurance (QA) campaign. To verify this QA process, a small subset of SiPMs were randomly selected after die removal for further testing. Thanks to Claudio Savarase, CENPA has received 10 of these devices for thorough characterization – of breakdown voltage, dark count rate, and correlated noise –  at liquid nitrogen temperature. In this talk I will cover the development process of building a vacuum cryostat for these tests, highlighting what did and what did not work for us. I will also show the results of characterization from the first few SiPMs obtained using the (semi-)automated data analysis workflow in the `sipm_studio` Python package. Finally, I will outline how to use this cryostat for controlled measurements of the cryogenic photon detection efficiency, expanding on work previously done at CENPA.