Some Thoughts About Food Safety and Overlap with Kashrut

Taking the food safety exam as a prerequisite towards working as a mashgiach, besides for being a delightful voray into so-bad-it’s-good 90’s era-internet graphic design, gave me a little bit of a deeper understanding of something I’ve noticed in Yoreh Deah.
There’s this concept in food safety called “The Danger Zone” which basically posits that any potentially bacteria-harboring food that is allowed to stay for an extended period of time between the temperatures of 41 and 140 degrees Fahrenheit, is now contaminated and should be thrown out rather than served. Food service should be dedicated towards making sure that food stays in the danger zone for as little time as possible, either by getting it above 140 degrees or below 41. Most of the questions on the test that you need to pass to get your food card come down to “danger zone”.
Interestingly, one of the gedolim in the field of Food Science, J. Kenji Lopez-Alt, in his book “The Food Lab”, notes that this danger zone criteria has significant issues, which are violated constantly by some widely consumed foods like aged beef or gourmet cheese. Temperature is obviously a factor in killing off bacteria, but so is time, and so is the environment. A cut of chicken that is vacuum sealed in a plastic bag and put in sous vide bath to cook for 6 hours is not the same thing as a cut of chicken left uncovered in a steam table for hours.
Lopez-Alt, however, doesn’t want you to think the danger zone is a dumb concept. He argues that such rules are intended to guide the vast majority of people in the vast majority of situations and give them a simple, easy to remember criteria to remember. Sure, one could pull out a graph of bacteria activity as a function of temperature and time and calculate the likelihood of contamination that way. But most of the people working in kitchens aren’t scientists and a easy to remember, easy to apply criteria that ensures everyone’s safety is much preferable.
I’ve noticed that in many instances of issur v’heter, the Rema in particular has a similar program, something I would call “conceptual simplicity is its own kula”. The Rema would rather give you an easy to remember and easy to apply criteria that may be superficially stricter but would require you to account for a number of other factors. Rather than mess around with trying to define what a taam issur is, which might, in many instances, lead to a more lenient position, the Rema would rather you just remember the number 60. Rather than do what was previously the widely held minhag in Ashkenaz and wait one hour between meat and milk, which would require a number of steps to allow (washing your hands and mouth and cleaning the table), the Rema would rather you just wait 6 hours. I remember running into more examples that I can’t recall offhand.
I think this is important to keep in mind when complaints are made about chumros in halacha. Certainly there are instances where such a complaint is valid. But I think that some thought should be put into understanding the possible “hidden leniencies” that are involved in some of these chumrot, that, while on the surface make more things prohibited, may allow Jews who have no aspiration to master the intriciate halachos involved to keep kashrut without confusion and with peace of mind.
An example of this, one where I’ve changed my mind, is that of stainless steel being used for both meat and dairy, on the argument that it doesn’t absorb taam. (Some summation of the arguments can be found here.) I was initially sympathetic to the argument, considering both scientific and programmatic (one set of pots is less of an expense, lowering the cost of living for Orthodox people)  Maybe so, maybe not, but using a pot for both like that would require making sure that the pot in question is always squeaky clean, which, for anyone who washes dishes, knows is sometimes easier said than done, and also may require knowing exactly when the pot was used for one flavor so as to make sure there was 24 hours between uses, which would be hard to track as well as hard to police other people from mistakenly using it during that period. (To be fair, an argument can be made that it would not require that, but I’ll admit to being b’safek on this point) While yes, its an extra expense getting another set of pots and pans, its a one time expense, usually given to you as a wedding present anyway, which ends up making your life much easier on a day to day basis. Its a stringency that is a conceptual leniency, and much like the US government wants regular people to understand food safety through a simple concept, I’d prefer that observant Jews need not be halakhic experts to follow halakha on a day to day basis.