I generally rely on primary fermentation only for my ales (that is, I don't rack to secondary after a few days but let it ferment completely in the primary) because my ales sit on the yeast cake for a month at most. However, if I were to use primary fermentation only for lagers, the beer would be exposed to the sediment for a long time so secondary fermentation would seem advisable.
Looking at Beersmith's fermentation profile for lagers, it seems that primary fermentation lasts a little less than two weeks, which seems reasonable enough: the lower temperature causes slower fermentation and in my experience, gravity measurements by the end of this time indicate that primary fermentation is indeed tapering off.
But, as far as I can tell, Beersmith considers the diacetyl rest to be secondary, thus having secondary fermentation take only two or three days. In ales, the secondary fermentation generally takes a little less than two weeks, so for lagers I'd expect it to be no less than a month given the slower fermentation.
So it seems I missed something. Does the diacetyl rest really cause the fermentation to complete entirely--thus making lagers ferment just as fast as ales? ... Or what did I miss?
Looking at Beersmith's fermentation profile for lagers, it seems that primary fermentation lasts a little less than two weeks, which seems reasonable enough: the lower temperature causes slower fermentation and in my experience, gravity measurements by the end of this time indicate that primary fermentation is indeed tapering off.
But, as far as I can tell, Beersmith considers the diacetyl rest to be secondary, thus having secondary fermentation take only two or three days. In ales, the secondary fermentation generally takes a little less than two weeks, so for lagers I'd expect it to be no less than a month given the slower fermentation.
So it seems I missed something. Does the diacetyl rest really cause the fermentation to complete entirely--thus making lagers ferment just as fast as ales? ... Or what did I miss?