1. Pre-heat flask first with a drop of boiling water and then empty.
2. If using milk, warm it up in the microwave before adding (not boiling though).
3. Leave an air gap and keep flask the right way up if possible.
I spent many months in Norway in mid winter and picked up a few 'flask tips'!
MS
I have had two proper Stanley flasks in two years, they have both failed. Returning them is not easy in the UK.
Simon
Classic Vacuum Bottle 1.1qt, Hammertone Green | ShopStanley-PMI.com
Life time guarantee I've had these flasks for 25 years plus if you get a problem with then you just send it back they'll send you another one .
, I can just imagine me trying to balance my MSR stove on the shooting rail of the high seat!Forget flasks, get a jet boil and have a piping hot brew in 90 seconds! Why have a stale brew or scoff when you can have fresh?
I've got a "Thermos" made in Battsville USA, .99 litre that providing you preheat will stay scorching for a good 12 hours but will get progressively cooler as you draw off. PS it's stainless, full of dents and must be 12 years old and still as good as the day I bought it...callie