Author Topic: FG target not reached  (Read 3517 times)

Offline Kevin J

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FG target not reached
« on: July 11, 2011, 12:11:15 PM »
I moved to all grain a few months ago. Bought the barley crusher, awesome!
I have a 10 gallon and a 15 gallon mash tun / brewpot. I use one or the other for the HLT depending on the batch size.
I can acheive the estimated pre-boil and OG right on the button but my FG is coming in quite a few points higher than estimated.
I'm assuming that I'm having fermentation issues. I get good airlock activity for 1 1/2 to 2 days then it stops.
I confess to reusing my liquid yeast most of the time.
I usually primary ferment in a bucket for 5-7 days and secondary in a glass carboy for 5-10 days.
The last time I brewed, I used fresh dry yeast and still have the same problem.
It seems like it started happening when summer started. Not sure if it is related. My house has good central AC set to 73 degreees.
I moved my fermenters into the cold (fruit) room in the basement to see if that helps. My last 10 gallon batch has been there for 8 days now in the primary. I was going to transfer them into the secondary 2 days ago but there was still quite a bit of foam on top. Does that matter?
I purchased some yeast nutrient for my next batch to see if that helps.
Do I need to pitch more yeast?
Any tips or ideas?

Thanks,

Kevin
« Last Edit: July 11, 2011, 12:31:49 PM by Kevin J »

Offline MaltLicker

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Re: FG target not reached
« Reply #1 on: July 11, 2011, 03:45:10 PM »
Batch size and gravity affect yeast's ability to finish batch.

Wet yeast = usually enough to ferment five gallons of 1.050 wort, assuming freshest possible condition.  Viability drops like a stone after one month.
Do you make a starter with liquid yeast?  Always a good idea, even if a small starter.

Dry yeast = 2x the yeast, assuming you re-hydrate it per instructions.  Do you rehydrate?

Either:  Do you aerate wort prior to pitching?  Yeast nutrients...water chemistry lacking magnesium or calcium...Temp differences with wort causing yeast shock. 

Offline Maine Homebrewer

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Re: FG target not reached
« Reply #2 on: July 11, 2011, 05:16:09 PM »
I would wait until all the foam has fallen before racking. 
Seven to ten days in primary is normal for me.
Give it another two days and I bet the krausen will be gone.
"To alcohol! The cause of - and solution to - all of life's problems!" -Homer Simpson

Offline Maine Homebrewer

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Re: FG target not reached
« Reply #3 on: July 11, 2011, 05:23:13 PM »
That foam on top is your yeast having a feast.
My guess is that your liquid yeast had less of a lag time than the dry yeast, shortening the total fermentation time.
I use Safeale 05 almost all the time. My last batch started two Sundays ago wasn't ready to rack until last Thursday. Twelve days. I'm thinking it was the honey. Honey seems to slow things down.

The risk of letting your brew sit in the primary for too long is autolysis, but that only becomes a worry after three weeks in high seventy degree range and longer at lower temps.

If you rack early then you could get a stuck fermentation or a secondary that bubbles for a month.

I'd wait a few days, at least until the foam is gone and only bubbly patches remain.
"To alcohol! The cause of - and solution to - all of life's problems!" -Homer Simpson