Was that all 'active' time or was there a 'put things in the dishwasher / autoclave and let it sterilize for X minutes?'
Were there a lot of separate parts to wash?
Now I'm curious :)
Not a snark.. it's quite eye opening to see (and actually use) how much food a piece of commercial kitchen equipment processeses in a day and then how much effort it takes to clean them.
An example of cleaning a commercial deep fryer: https://www.youtube.com/watch?v=oFR5CN_kuI0
One can also try googling for other more detailed versions showing all the efforts in digging out all the burnt sediments/sludge :)
The McD procedure involves draining the barrel, flushing it with water, then disassembling each barrel assembly and removing every o-ring and gasket.
https://youtu.be/SaYTx7qNJU4?si=Y2ZjWHQJHiKQfAFh
Each part is washed in detergent, rinsed, and sanitized. Rings and gaskets are relubricated with food safe petroleum jelly, then everything is reassembled.
Forget one ring or misalign one gasket and the machine will shoot dairy everywhere when repressurized. Cleanup and rework after that is messy, and probably wasted a lot of other nearby product and disposables. So don't do that.
After reassembly the machine is flushed with sanitizer then clear water then primed with the mix you saved from the beginning. Let's hope you stored it properly in the cooler before it started to spoil. It's expensive. If nothing has exploded it's ready for use after an hour of cooling down.
To do this in 45 minutes with no catastrophic errors is pro-level. And this is why McD went to a self-sanitizing machine.
The machines were reassembled the next morning. So the closers only had to break them down, wash, and sanitize.
Once a week any dairy mix left in the machine was discarded, this "breaks the cycle" of any bacteria in the mix. So on that night, you tried to let the machines run very low to minimize waste.
It's sort of complicated the first few times but it becomes very routine. Like everything at McDonalds, there is a detailed step-by-step written procedure on how to do it.
I'm guessing 24/7 operation changed when and how the cleaning was done, leading to more contamination instead of less.
The new machines came in long after I moved on to other jobs. In ideal situations, they re-pasteurize the mix overnight, leading to a drop in 1-2 person-hours of labor.
(And it’s often skipped, if you ever get soda that tastes off you’ve found someplace that doesn’t deep clean.)