Ah, chemeng, you really know the answer.. (oops, maybe not, its as much biology as chemistry.)

there are two basic yeast used to make beer, one like colder tempertures, one warmer.. German beer uses the cold yeast, and beer can not be brewed till it get cold enough (late september..and 4 to 6 weeks later, the first new beer is available, and you have an OctoberFest... in late spring, (say March) beer is made for keeping.. (higher alcohol content) since it starts getting too warm to brew..
that "strong beer" has to last till October.. (only it never does, and there is a dry spell in early fall..)

with modern refridgeration, beer can be brewed year round..

do we have any home brewers on the board? its small hobby here, but my understanding is it is more popular in UK. they might know the names of the different yeasts.

(in US, each household can brew up to 50 gallons of wine or beer for home use with no taxes added. over 50 gallons is considered commercial production and is taxed-- but it is always illegal to distill.. )


my other obsession