Using freezer for a Kegerator an for fermentation?

Hello how does one counter the residual cooling Effect that freezer cause meaning for Instant I have my keg in my freezer an I have my temp controller set to 40f with a 2 degree differential now the issue is when it start to cool after it reach 42f it cool down to 37f I guessing because of the residual cooling in the cooling lines in the freezer. So the ? Is how do I counter this residual cooling

If fermenting monitor the temp of the wort not the freezer.

Are you talking about fermenting while you have kegs at 40°F? Like a lager? Or just the residual cooling at any temp? I have a chest freezer that I only ferment in. I don’t currently keg. The few degrees it over shoots won’t change 5 gallons of wort that much before it returns to equilibrium with the temp of the fermentor. Like @uncdeo mentioned you should be using the probe to read wort temp and not ambient temp. If you try to adjust the diff or if you have 2 stage temp controller you would be over cycling between heat and cool if you try to adjust it too tight.

No I have my temperature Controller probe tape to the side of my keg with a couple of washcloths covering the probe so it would measuring the temp of my beer an not the Ambient air temp. An it still swings from 40f which that what my temp controller is sat at an with a 2 degree differential it cool down too the 40f which is were I have it set but it seem the residual cooling in the coils in the freezer still cause the temperature to go down to 37f