I'm still pretty new to home brewing, so I'm sure I made about a hundred mistakes with this beer. I brewed a 1.079 OG imperial porter, and used Safale 05 (only one pack, unfortunately). First of all, I think I under-pitched the yeast, and then I only kept it in primary for seven days. I tasted it during racking, and there were definitely some pretty distinct fruity flavors there that I did not expect or want. The gravity read 1.032, so I assumed I did not have enough yeast for that big of a beer, and the yeast got really stressed out, hence the fruit. I added 1.70 cups of bourbon, an ounce of oak chips, and three cut-up vanilla beans at secondary, as per the recipe that I found. Since the gravity was still so high, I repitched into secondary with a new pack of 05, hoping that would kick-start more fermentation and get the gravity down to 1.017 where it's supposed to be. After four days, there is barely any activity in the airlock, so I don't think it's fermenting. Is there any hope for this beer turning out, or for those fruity flavors to disappear? I'm also concerned about leaving it in secondary with the oak chips and vanilla beans for too long. Could someone please point me in the right direction?
There are a couple of things that you can do to prevent the esters from occurring in your next brew
The fruitiness will reduce over time, espeically in big beer like that which can take a year or more to reach maturity, by which time the esters will definitely have lessened, so don't give up on this one just yet.
Pitching dry yeast directly into secondary with a high alcohol content will lead to a poor fermentation. It will probably pick up eventually, but may need 3-5 days to get going. Next time, rehydrate the yeast first, and ideally make a small starter and pitch when at high krausen. This gives the yeast the necessary kickstart to get fermentation of the bigger beer going.
Unfortunately, little or lack of air-bubbles doesn't always mean no fermentation - best to take a gravity reading every couple of weeks to know for sure. US05 is hardy and works down to fairly low temps, but even so, raise the temperature to 65-68F if it's below that to give the yeast some extra help.
You may also want to try a forced ferement, to find out what the actual FG for this brew is. Then you know exactly what you're aiming for.
As a new brewer, you're bound to be anxious about the brew and curious to find out how things are doing. One of the best tools available is time, which can fix many problems, especially with the big beers! Take a gravity reading in a couple of weeks and I'm fairly confident you'll see the gravity falling.