I had a bit of a discussion in the car as baselodge thread about using one of the food warmers from Amazon so that one might have warm food on a cold day if using one's car (or likely in my case, @kimberlin's car, as baselodge). I decided to buy one and do some experiments. I bought a "Electric lunch box". It works off both 110V and 12V or 24V. Dissembled, it looks like this:
As a test, I filled it with water and plugged it into 110V. After 2 hours, the water was at 180F. I redid the test at 12V and after 2 hours, the water was between 136F and 140F.
Then for a more real world test. I put a load of freezer bags in a cooler to emulate Kim's car on a cold day. I made some porridge/oatmeal to emulate the consistency of something like a chili or a stew. I then refrigerated the porridge until it read 41F. I then put it in the cooler and plugged it in using 12V.
Figuring that Kim & I usually ski from 9am lift opening to midday before breaking for lunch, and allowing for time to get to the car, I left the lunch box on for 3 hours 10 minutes. When brought out, the temperatures of the porridge, unstirred, ranged from 130F to 143F. While this is supposedly just on the cusp of food safety, the 140F often quoted is an instantaneous temperature, which is why one can sous vide safely at lower temperatures. Anyway, I figure, it is likely safe enough and I may have a way of increasing the temperature a little. The only other thing I might mention is that the porridge had become a bit dehydrated by the end, so one might want to have a slightly liquidy stew/chili/curry whatever to start with so that one's gourmet repast at lunchtime is more appetizing.
Although I was using a mains transformer with a 12V cigarette outlet, I am assuming that in winter at Snowbowl I will take along a 12V battery pack which I can charge back up between ski trips. As for increasing the temperature a little, I think that one's non-ski outside jacket loosely thrown over the top might well add a bit of insulation and help the temperature. YTMV.
As a test, I filled it with water and plugged it into 110V. After 2 hours, the water was at 180F. I redid the test at 12V and after 2 hours, the water was between 136F and 140F.
Then for a more real world test. I put a load of freezer bags in a cooler to emulate Kim's car on a cold day. I made some porridge/oatmeal to emulate the consistency of something like a chili or a stew. I then refrigerated the porridge until it read 41F. I then put it in the cooler and plugged it in using 12V.
Figuring that Kim & I usually ski from 9am lift opening to midday before breaking for lunch, and allowing for time to get to the car, I left the lunch box on for 3 hours 10 minutes. When brought out, the temperatures of the porridge, unstirred, ranged from 130F to 143F. While this is supposedly just on the cusp of food safety, the 140F often quoted is an instantaneous temperature, which is why one can sous vide safely at lower temperatures. Anyway, I figure, it is likely safe enough and I may have a way of increasing the temperature a little. The only other thing I might mention is that the porridge had become a bit dehydrated by the end, so one might want to have a slightly liquidy stew/chili/curry whatever to start with so that one's gourmet repast at lunchtime is more appetizing.
Although I was using a mains transformer with a 12V cigarette outlet, I am assuming that in winter at Snowbowl I will take along a 12V battery pack which I can charge back up between ski trips. As for increasing the temperature a little, I think that one's non-ski outside jacket loosely thrown over the top might well add a bit of insulation and help the temperature. YTMV.
