Just started an Coopers Amber Ale. Started out good....bubbled profusely for 2 maybe 3days and then just stopped? It slowed down to almost no bubbling in the airlock. Did take a sample from the tap and its down to 1012 on the hydrometer. Will do another this afternoon. Is the sudden slowing down of bubbling in the airlock a problem? Id prefer not to open the fermenter. What else could be an indication that something went wrong?
What makes you think that something went wrong? It is normal for the fermentation to slow down, specially if you are close to your final gravity. The speed of fermentation can vary for several reasons, no problem there.
What you need to do, is to take one gravity reading per day and if the gravity doesn't change for 3 days in a row, the fermentation is done. No need to take a reading more than once a day.
As for the taste, if you use a Cooper primary fermenter with a spigot at the bottom, the yeast tends to accumulate in there, which would make your sample taste "yeasty". Use a wine thief to get a sample from above to avoid that. For the same reason, I would not use the spigot for bottling either, unless it was cleaned before.