Tempering Butter

Hello all. I think this has been discussed before, but I need additional help.

We need to warm (temper) unsalted butter to room temp before we can mix with it. Where can I find a guide or scientific study showing how long butter can remain outside the cooler safely? Or is there a industry standard temperature?

We do not have a hot box. We are using 30# blocks of butter.

Thank you for your help.

Miranda

Here is a general article that also references an FDA supported document.   It all comes down to fat content. 

https://www.statefoo...ble to bacteria.

I was at a bakery prior that would use the same 30# size blocks and we would stage in original sealed packaging overnight at ambient for use the next day.  I wouldn't personally go past one day sitting out at ambient as you should have a process control in place for rotation back to the cooler if needed.