Posted by Peter Ceresole on October 09, 2007 at 17:01:02 from 80.176.146.133 user PeterC.
In Reply to: keeping food cool - back to basics posted by Jock on October 09, 2007 at 15:52:58:
So how does a well aired larder, which in summer would presumably entail a draft of hot air, keep food cool?
By our standards it didn't, but for things like butter, which would go off pretty quickly in summer, there were always porous unfired pots which stood in water and cooled by evaporation. Alternatively a dampened cloth would do. This is where the 'well-aired' came in. Circulating air helped to evaporate the water. Remember the latent heat of evaporation of water is 540 cals/gm, a useful figure. I remember my aunt's pre-electric chalet, which used this system. In really hot weather, it didn't always work that well...