I personally like hot coffee and to me mug’s ability to keep drink warm is important. Especially outdoors in poor weather. But in the office too – it’s quite nice to drink warm coffee at a long meeting while others are sipping it cold.

So we decided to run a small test and compare Bogmug to a standard ‘clay’ coffe cup; to a old time porcelain or china cup; to gas station paper cup and finally a good quality traveller’s thermo mug. 

Theory – a cup’s ability to keep drinks warm or cold depends on a lot of things, but shortly it comes to two main features: 

1. how much heat can disappear from the walls and bottom – the better heat conductor the walls are, the quicker drink cools down. In a metal camp cup drink cools almost instantly while in vacuum thermos it may stay warm over 24 hours  
2. mug design – how much heat can disappear from the upper open part of the mug. Or in other words how big is the open area compared to the amount of liquid. A good example is soup serving – in a flat plate soup cools much faster than in a bowl. This is also why thermos bottles trend to have quite small openings.  

Testing – we heated up water to 85 Celsius and poured it simultaneously into all ups being tested. We left the cups in the same room for 15 minutes and measured the temperatures, the results were the following: 

Comment – It’s no surprise the travellers cup was the best as the design and construction resembles most thermos bottle.