joe80ci wrote:I am new to this . Made my first batch using true brew ipa kit. bubbling in air lock started 2 hrs after pitching yeast that i pre activated. bubbling only lasted 24 hrs. is that a problem or indication something is wrong?
That depends on whether they stopped fermenting because they consumed the sugars in the wort (in which case everything is OK) or they stoped before they acheived that goal. What happened to the specific gravity? If the "points" went down by at least 70% then you are probably OK e.g. if the beer started at gravity 1.050 and is now at 1.015 or less then fermentation is complete. It can happen as fast as 24 hours but that would be unusual unless temperatures got quite high. Taste the beer because high temperature fermentation can lead to unpleasant levels of esters and fusels. There is also another scenario in which the beer is rapidly hyperattenuated by a wild yeast strain. If the gravity is low and it tastes OK then it's a keeper. If it tastes bad (i.e. infected or loaded with fusels/esters) toss it (unless its Belgian).
If, OTOH, the gravity is appreciably above 1.015 and fermentation has stopped then there is a problem. This can be from bad yeast, insufficient aeration, lack of FAN or a host of other causes. Adding a bit of yeast nutrient and rousing is usually the first thing one tries followed by repitching with fresh yeast. Again, it is wise to taste the beer to be sure that the fermentation which took place to the extent that it did take place was done by the yeast you put in and not some wild strain. If it tastes bad then that's what happened and repitching won't make those awful flavors go away. If it smells and tastes (except for excessive sweetness) then trying to get the yeast going again is worth a shot.
