I do have a question....how much differance will a few deg make in fermentation....and i mean in real temp, deg c
ok in deg f will 4-6 deg make a huge impact[/quote]
Temperature control is everything in making a balance beer. A temperature change in a ale more than 2 degrees can add more fruity esters, haze issues, and could stress your yeast to the point where they won't consume diacetyl.
Temperature for lagers is key to making a clean crisp beverage. Lager anywhere from 48-54F with no more than a 2 degree swing is ideal. Lager yeast don't consume their own bi-product as ale yeast do, so it is important to make sure you control the ferment properly. As a brewer, remember you are actually a yeast farmer manipulating an environment to produce a flavor from a certain yeast. Stressing any yeast with off the wall temp will add unwanted flavors.