Need sugestions to get F.G. to expected gravity

[nasmeyer]

My basement is too warm during the summer to brew, but now that fall is closer I am getting the itch to start again. I am trying to work out some bugs to improve my beers. After going over my notes I can see that many of my extract IPA’s finish higher than the recipe instructions call for, instead of 1012-1014 they finish closer to 1017-1020. This usually creates way too much carbonation in my bottles, and I notice off flavors too. What can I do to make them finish lower or at the expected F.G.?

I have ramped up my fermentation temp from 66* to 70-71* after 3-4 days of fermentation without much success. Can more active yeast be added to the fermenter once I have determined that fermentation appears done or stuck?

Can high hop bitterness hinder fermentation? I have often done full 5 gallon boils to get more bitterness from my hops through better utilization and was wondering if this could slow fermentation down and possibly require me to use a bigger starter? Would just using a huge starter solve my problem without nasty side effects or if a batch is destined to end high it will do so regardless of starter size?

Any suggestions?

 

[Nateo]

I perform fast ferment tests on all my beers:
http://braukaiser.com/wiki/index.php/Fast_Ferment_Test

It's really the only way to know for certain if you're missing your target because of the yeast, or because of the wort.

Since you mentioned overcarbonation in your beers, I suspect the yeast is the biggest culprit. Are you pitching a large enough and healthy enough starter?

 

[nasmeyer]

Since you mentioned overcarbonation in your beers, I suspect the yeast is the biggest culprit. Are you pitching a large enough and healthy enough starter?

I have used the pitching table at Mr Malty and believe I am using enough. Wouldn't unfermented sugar from a stalled batch of beer be a likely suspect to cause over carbonation in bottles? Over time the yeast would continue to eat the extra sugar and continue to carbonate wouldn't they?

 

[Nateo]

I have used the pitching table at Mr Malty and believe I am using enough. Wouldn't unfermented sugar from a stalled batch of beer be a likely suspect to cause over carbonation in bottles? Over time the yeast would continue to eat the extra sugar and continue to carbonate wouldn't they?

It's possible that the yeast kicked up and started fermentation again, but the more I think about it, I'd say it's likely that you got some sort of infection.

All organisms are inherently lazy. Wort is composed of lots of different kinds of sugars, some simple, some complex. The yeast will eat the easiest meals first (the simple sugars) then move on to the more complex sugars when they run out of simple sugars.

So any unfermented fermentable sugars post-ferment are going to be complex sugars. You add simple sugars when you bottle, and you know that the yeast can process that kind of sugar well. But in the bottle they have to eat the simple sugar, and then eat the complex sugar, which is something they couldn't really do that well in the first place, and the bottle is less hospitable place for fermenting than the initial bucket, since the pH is a lot lower, there's no oxygen, and there's now alcohol.

I've bottled beer with an excess of complex fermentable sugars (high FG) and not had them turn into gushers, and I've had gushers from beer with the FG in the proper range.

I think maybe having a beer with a higher-than-wanted FG means an easier meal for the bugs, they reproduce and the beer overcarbonates.

I don't know, that's just a guess.