High FG

Hello everyone, I am fairly new to home brewing, I have made wine for years but decided I wanted to get into home brewing beers that I really enjoy. I have made a total of 5 batches so far, all extract brews (working my way up to all grain). My question is and I think I know the answer but wanted some confirmation, My OG numbers are right where I want them, but the FG numbers are bottoming out a little high, some where in the 1020 range. I think the issue is not pitching enough yeast, I set my fermenters up in the basement where the temperatures run around 68 to 70 degrees. All I have finished so far is Ale's. I have a lager working and the numbers are a little high on it also when I moved it to secondary. I am building a stir plate so I can pitch a better yeast concentration. on my next batches. What do you think?

Pitching proper numbers of yeast as well as thorough aeration are essential to healthy, vigorous fermentation which will yield proper attenuation. Pitching enough yeast will help overcome lower wort oxygen levels since yeast are aerobic only during the budding phase.

There is a technique call Forced Fermentation that may help you get the answer. You take about 500ml's of your pitched wort, keep it nice and warm..like in the 80's and preferably on a strip plate with an airlock. This will ferment fast...a few days. Take a gravity reading. I call this Absolute Gravity, I cannot get lower than this. Compare this to your FG.

Your FG will always be a higher than your AG but it gives you an idea about how fermentable your wort is. If the AG is 1.009 and you are in the 1.020's then you know the wort is good and that you have a process problem (pitch-rate, ferm temp, etc). If your AG is 1.018 and you are in the 1.020's then you know you have a fermentability problem, i.e. your wort is the problem.

I try to provide plenty of oxygen, I do not have an oxygen system yet but I do poor back and forth between a couple of buckets a few times to try to put as much oxygen as I can in the wort. I will try to add a little more on the next batch and see if that helps.

My understanding is that extract batches often stop around 1.020... I only brewed 4 extract batches before making the move to AG and I lost my paper brew log from that time in my recent move (started using beersmith when I moved to AG), but I seem to remember my extract batches finishing a little higher than expected.

Pitching enough healthy yeast - either dry or making a starter from liquid - is a best practice, but it may or may not get your FG on extract batches to drop a few more points. When you do make the move to AG, you will have a lot more control over where your beer finishes.

Also, I know you didn't ask about this, but you may also want to look into making a swamp cooler to control your ferm temps... The temp of fermenting wort/beer can be 5-10 degrees higher than ambient, so 68-70 could really be 73-80 wort/beer temp during active fermentation, which is a little high for most yeasts and styles of beer. Basically, you put your fermenter in a tub of water and change out some frozen water bottles a few times daily to keep the temps down. A quick search will lead you to some more detailed instructions.

Welcome to brewing beer!

Thanks I will try that with the next batch, I hope to finish my stir plate in the next couple of days

Thanks, I hope to move to all grain in the next few months

As for the temp, that was actually the temp of the wort, my basement stays very cool. But thanks for the advice.

Pitch enough healthy yeast, control ferm temps, and expect extract batches to end around 1.020. Go all grain if you want your FG to end up where you expect.

thisoneguy said:

My understanding is that extract batches often stop around 1.020... I only brewed 4 extract batches before making the move to AG and I lost my paper brew log from that time in my recent move (started using beersmith when I moved to AG), but I seem to remember my extract batches finishing a little higher than expected.

Pitching enough healthy yeast - either dry or making a starter from liquid - is a best practice, but it may or may not get your FG on extract batches to drop a few more points. When you do make the move to AG, you will have a lot more control over where your beer finishes.

Also, I know you didn't ask about this, but you may also want to look into making a swamp cooler to control your ferm temps... The temp of fermenting wort/beer can be 5-10 degrees higher than ambient, so 68-70 could really be 73-80 wort/beer temp during active fermentation, which is a little high for most yeasts and styles of beer. Basically, you put your fermenter in a tub of water and change out some frozen water bottles a few times daily to keep the temps down. A quick search will lead you to some more detailed instructions.

Welcome to brewing beer!

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All of this is true, especially the bolded part. It's quite common. Some things you can do to help extract brews finish a bit lower are: Add all or some of the extract at flameout instead of boiling it. Add a small amount of simple sugar, like corn sugar or sucrose (table sugar) but keep it restrained, ~5% or so of the total fermentables at most is good, IME. Boil as much of the total batch volume as possible when adding any of the extract during the boil. And always be sure to pitch enough good yeast and aerate the wort well.

NordeastBrewer77 said:

All of this is true, especially the bolded part. It's quite common. Some things you can do to help extract brews finish a bit lower are: Add all or some of the extract at flameout instead of boiling it. Add a small amount of simple sugar, like corn sugar or sucrose (table sugar) but keep it restrained, ~5% or so of the total fermentables at most is good, IME. Boil as much of the total batch volume as possible when adding any of the extract during the boil. And always be sure to pitch enough good yeast and aerate the wort well.

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This! I couldn't have said it better!