Our problem is that acorn squash turn orange after about 2 months of storage at room temperature. What causes them to turn orange and how can we store them better?
There are acorn squash of different colors, but yes, the green skinned Acorn squash will eventually turn color as they age in storage. This can be related to storage temperature and possibly ethylene exposure. The warmer the storage temperature, the more susceptible they will be to degreening. This is due to chlorophyll breakdown and unmasking of the yellow-orange carotenoids. I would avoid delays from harvest to cooling for storage, maintain the storage temperature near recommended (about 55-59F or 12.5-15C) and make sure they are not stored with any ethylene producing products. Also propane forklifts produce ethylene as a byproduct of internal combustion and therefore avoid using those in the squash storage area or ensure there is a lot of ventilation to remove any ethylene. Any squash with decay will also produce ethylene, so remove decayed squash.