Effect of Daily Temperature Changes on Skincare Product Stability
Question
I store skincare products like Rosehip oil and toner in a hot room, but sometimes put them in the refrigerator. Is it true that repeatedly moving them between the hot room and the refrigerator daily will cause them to degrade faster than keeping them in the hot room consistently? Would it be better to keep them permanently in the refrigerator and only take them out briefly to use?
Answer
Based on the previous discussion, storing Rosehip oil in the refrigerator is generally a good idea, especially if your room is hot, as it helps protect it from heat and light.
However, the key issue is the repeated change in temperature. Taking the oil (or other products like toners) in and out of the cold refrigerator into a hot room every day causes temperature fluctuations (sometimes called the freeze-thaw cycle, even if it doesn't actually freeze) which can degrade the product quality faster than keeping it at a consistent temperature, even if that temperature is warmer.
So, keeping the oil permanently in the refrigerator and only taking it out briefly to dispense the amount you need before putting it straight back is a much better approach than moving it in and out daily. This minimizes the exposure to temperature changes.
And yes, this principle of temperature fluctuations causing degradation applies to other products like toners as well. Storing them away from direct heat and light is always recommended. If your room is very hot, keeping them in a consistently cool place like the refrigerator (and minimizing the time they are out) can help maintain their quality.