Hi to all, If you want to join in with the testing using whatever thermometer your welcome too will have to state what thermometer was used for testing and we will test every 6 hours up to 12 hours and preferably pre heat the flask with boiling water by fully filling up the flask for 2 minutes and then drain and then refill fully again with boiling water or not (if your doing a cold test that is) and then start the test. We will be using this for the results > https://docs.google.com/spreadsheets/d/1r0ZEVhnXF97QpugLyveziQB0vIAPz8T1bz6sRLTNlUE/edit#gid=0 if you want to publish your results on that google doc link, ask for editing rights as for new people or people you can only view it. I have decided to make a thread about thermal flask bottles, which are designed to keep your liquid hot or cold over many hours. The reason why i have made this thread is because so many sites test these thermal flask bottles and they say that this is the best you can get or this is the best. So me being me going through all these websites, i have bought these thermal flasks the ones they say is the very best and i want to know first hand what is the very best, well these flasks would be one of the best or the best. I want to test these flasks so i will need to get something to test the temperature of the water etc, I have bought 1 litre flask bottles so the test will be fair because bigger the flask apparently the better it can retain heat for instance. I have a sigg hot and cold 1 litre bottle, a stanley the classic bottle 1 litre and a klean kanteen tk pro 1 litre bottle and i have more flasks coming as well so i will wait for them to be delivered to my door. Right well i have a thermos ultimate series flask 900ml coming and as well as a Zojirushi flask coming. From what i have read apparently the thermos ultimate flask will be the contender for the title of being the very best flask at containing heat because many people have said that this is the best flask they have had out of many. I will have 5 thermal flasks in total, 3 in the picture above all 1 litre and a 900ml thermos ultimate flask as well as a 2 litre Zojirushi flask, i won't be testing the Zojirushi because it is 2 litres and is not fair because a bigger thermal flask retains heat better when compared to a 1 litre flask. Apart from the thermos ultimate flask, the Zojirushi flask is also considered to be among the very best like the same as the thermos ultimate flask, why these two because of what i have read about them, they keep the liquid so hot it will burn your lip as in keeping the water hot from when you put liquid into them and being like that same temperature 6 or 12 hours later that is. So i want to test these flasks so if the information is credible or not well that is your choice. Any criticism is welcome.