Can't hit target FG. How to make high gravity beers?

[SandTiger]

Was trying to make an Imperial Bourbon Porter. Just racked into bottles today, and was slightly disappointed with it's strength.

My OG target was 1.087 after boil. I hit that exactly, which was a first and got me super excited. But finished at 1.036-1.040 not the target 1.020

I use a freezer with external thermostat control to keep it at 63F. Primary for 4-5 days, then secondary for 7-10 days.

What went wrong?
My thoughts: I did fly sparging, and forgot to mash out. I never got my mash out temp at 170f. My mash tun was at 155F while I added water at 170F for fly sparging. Is that a problem? My understanding is that it should have made it more fermentable, not less?

I used two packets of Wyeast #1450. Would 3 packets, or even a starter, made the difference? I also used 5.2pH stabilizer in the mash. I did not add any yeast nutrients, should I have added servomycies(sp)? I did oxygenate properly. I have a O2 tank with micropore stone that I use for about 45 seconds.

After boil, when I cold crash, I get the wort down to about 85F and then pitch. In Arizona its hard to get it down colder. Would that have caused the yeast shock to then be chilled down to 63F?

My beer is drinkable, but a little sweet. But while 6.8% ABV ok, it's not the 8.8% ABV I was shooting for.

Thanks for reading, any help is appreciated.

 

[poptarts]

Treat your water or start adding yeast nutrients and energizer. and yea 2 pack might not be enough, my last big stout I had over a gallon starter going. user mr malty to calculate pitch rate.

 

[WI_Wino]

I would also keep the beer in primary until you hit final gravity. With high gravity beers I would hazard a guess that racking off of the yeast cake at day 4 could be a reason for the high FG.

 

[Oceantendency]

4-5 days in Primary ??? That high of an OG, should've been a min of 10-14 days. Starters make a HUGE difference on those big boys. I've brewed several Belgian Abbeys and time is the essence, you rushed a bit through the process, and also didn't allow the temp to rise at the end before transferring to a secondary, even a few degrees let's it finish off, depending on the yeast. I would've let it age for a min 2 weeks in secondary as well. Bigger beers need more time.

 

[MindenMan]

A beer that big needs to primary a lot longer than 4 or 5 days. My last 1.080 beer was held at 55* F, for around 3 weeks in the fermenter, raised to 68* F for about a week, and as I recall, I cold crashed at 34 for 5 or 6 days. My FG was supposed to be 1.020, and I know I was really close.

 

[SandTiger]

Thank you everybody for replying! Sorry for the super late reply.

So it looks like I'm going to need get a stir plate and flask in order to get my yeast counts up. I'll try putting some yeast nutrients in, and also leaving it primary longer or not putting it in secondary at all.

Just tried the beer a few nights ago. It wasn't fully carbonated yet, as expected. It was too sweet and I had trouble finishing the whole bottle.

On a side note my wife tried it and said "hrm... yeah.. not too bad". I knew I was screwed then. She hates beer. The worse her reaction is the better the beer.

 

[RM-MN]

Was trying to make an Imperial Bourbon Porter. Just racked into bottles today, and was slightly disappointed with it's strength.

My OG target was 1.087 after boil. I hit that exactly, which was a first and got me super excited. But finished at 1.036-1.040 not the target 1.020

I use a freezer with external thermostat control to keep it at 63F. Primary for 4-5 days, then secondary for 7-10 days.

What went wrong?
My thoughts: I did fly sparging, and forgot to mash out. I never got my mash out temp at 170f. My mash tun was at 155F while I added water at 170F for fly sparging. Is that a problem? My understanding is that it should have made it more fermentable, not less?

I used two packets of Wyeast #1450. Would 3 packets, or even a starter, made the difference? I also used 5.2pH stabilizer in the mash. I did not add any yeast nutrients, should I have added servomycies(sp)? I did oxygenate properly. I have a O2 tank with micropore stone that I use for about 45 seconds.

After boil, when I cold crash, I get the wort down to about 85F and then pitch. In Arizona its hard to get it down colder. Would that have caused the yeast shock to then be chilled down to 63F?

My beer is drinkable, but a little sweet. But while 6.8% ABV ok, it's not the 8.8% ABV I was shooting for.

Thanks for reading, any help is appreciated.

The way you handled the yeast should give you a high enough cell count but you might have to increase the time to 60 seconds to get sufficient oxygen dissolved to get your propagation where you need it. I think your biggest problem is not giving the beer enough time on the yeast and then not warming the beer to help the yeast finish.