I think adding beads or a humidification device is what would cause the large swings. Since there is little humidity in the fridge it stays at 55%. Now if you could get it to stay at a temp the whole time your RH should stay constant. Anytime temp goes up or down the RH will shift as well, so when that compressor kicks on I would imagine it's a blast of way colder air than whats in the vino, the thermostat regulates how long to cool to get the desired temp and not an adjusted cooling setting. Does that make any sense? So maybe buying a hydrometer that has high and low points in a 24hr period might be the first step to accurately tell if you are having swings. It took 6 years in Va summers for beetles to hatch for me. After that happened I rushed and got a wine cooler (newair) off ebay for 170$, then bit the bullet and froze my stash. After that I really did not need the wine cooler but the extra space helps
And had zero issues with my frozen sticks. I would recommend freezing what you have or buying a wine cooler
