I wish I could say I had some master plan for equipment but, the truth of the matter is that I took the idea of a thermos and a handful of thermodynamics pointers and walked into an REI to see what I could find. Luckily double wall vacuum insulated vessels are very much in fashion, I was blown away by options. Even the particular niche of craft beer aficionados had a whole host of new products designed to meet their needs. Note: the nearly sold-out shelf of portable double walled vacuum insulated kegs. In the end, I walked out with two types of vessels, one super portable for cooling warm milk down and gathering ice from soda fountains, and two large storage vessels for holding cold or frozen milk at temperature for the duration of the trip home.
I’m not sure the clerk at REI was ready for a prototyping session to take place in the front entrance of the store. But there was no right place for coolers to be laid open, measured, and weighed. After rapidly assembling one potential solution I’d pick it up, realize it was way to heavy to travel with, disassemble it all, and then try again. I was initially drawn to the hard coolers assuming they would hold temperature longer. The interior dimensions were smaller in every instance than their soft cooler counterparts. When trying to jam in two gallon-sized jugs the choice to use a soft cooler was more or less made for me. I tried a few times to imagine a system with just a cooler and ice, forget these big cumbersome jugs. Then I reminded myself that the only instance of success I’d read about to date had utilized a thermos and that thermoses were extraordinarily efficient at holding cold temperatures cold. I started to imagine the rambler jugs as the heart of the operation and selected only coolers and ice that would allow me to carry them. What I ended up with was a massively scaled up version of two thermoses tucked into luggage.