Brewing lager

[shibao123]

I am brewing lager with LME at 21 * C . Why after 3 days the fermentation becoming very slow nearly stop. Anyone could help me

 

[BigEd]

Sorry but @ 21C you are brewing ale. The fermentation has slowed because it is about finished.

 

[JLem]

Sorry but @ 21C you are brewing ale. The fermentation has slowed because it is about finished.

Or he might be brewing a lager much too warm...(too warm for ale too in my opinion).

What yeast are you using? If it is truly a lager yeast, you should be fermenting much much cooler. It will ferment at 21C - quite rapidly in fact - but you will end up with a bunch of off-flavors.