Wed, 25 Jul 2018
In my email today I found a note I sent to myself on 24 June 2015 that says only:
which would be useful, if you don't drink your sake so quickly that it is gone before it has cooled.
As far as I know, these are not common and perhaps do not exist at all. Why not? Is this a billion-dollar idea?
A few problems come to mind. If the bottle has a cord, it will be hard to pour and will be easily upset. Maybe the best choice here would be a special power supply with relatively high voltage and a thin cord such as is used for earbuds. But this might be dangerous, or impractical for other reasons I am not thinking of.
I think battery power is also probably impractical. Heating requires a lot of energy and batteries don't supply enough. They would need to be frequently replaced, which gets expensive.
Also temperature control might be troublesome. You would need some sort of thermostat in the bottle. Typical inexpensive heating containers and immersion heaters are for bringing water to a boil, which is much simpler than warming sake to the right temperature: just dump in as much heat as possible, as quickly as possible, and perhaps also arrange to have the heat shut off if the heating element gets up to 100°C. This is much too hot for sake.
I think a more practical solution would be a tabletop hot water bath with a bottle-shaped depression in it. The hot water bath could have the thermostat and be permanently attached to a wall outlet. You insert the bottle in its bath to keep it warm when you are not pouring.
This seems practical enough that I imagine it already exists. In fact it occurs to me that I owned a similar sort of warmer at one point, for warming baby bottles. But a quick perusal of available sake warmers suggests that this approach is not common. What gives?