I used to work in a restaurant when I was a teenager. We had those huge coffee makers, probably a couple gallons, back then, not the drip pot types we have today.
There was a solution, lye I think, that I had to use to clean then once a week to get rid of the buildup of stain and acids on the insides.
I would empty the tank and pour in this packet of powder then fill it with scalding hot water. It would bubble and sizzle and I would let it set for about 30 minutes then drain and rinse several times. The dirty water that came out was terrible. But the coffee after cleaning was really great...................
Oh dang! ME TOO! Wow did that just trigger a whole bunch of memories.... I bussed in my teens and waitressed in my 30’s. Bussing was FUN but oh those waitressing tips .... $1000 a week in cash, until a massively broken foot ended my side hustle, and caused a chain reaction of events I’m still recovering from ...
But anyway - I love restaurant kitchens - at least the ones I worked in. Those big coffee pots were daunting. Needed a step ladder to reach the top.
My dream kitchen has stainless steel counters and a drain in the middle of the floor. THAT is a “professional kitchen”, aye?