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I am considering two techniques for lowering my specific gravity but am unsure if my methods will work. I am currently fermenting a bock style. It's not a true bock because I don't have the ability to lager, so I used an ale yeast, specifically, Safbrew T-58, per a friend's recommendation.

My original gravity was 1.071. After taking 5 measurements over the course of a week, the gravity has stopped at 1.025. I was hoping for it to be a little lower, but I became concerned when I read this yeast may not be ideal for high alcohol brews. Temperature has been ideal according to package. I can't do much about room temperature anyway because my brewery is a spare bedroom in my house. My conclusion is that fermentation is not prematurely stuck, it's just the yeasties are are maxed out and done all they can do.

I bought some nutrients and a pack of Safale K-97 dry ale yeast which said "high attenuation" on the package. I don't want to make a whole starter and repitch because I'm worried that will void out my previous SG readings.

So here is my question. Can I just agitate the wort a bit and repitch the new yeast with the nutrients (without making a starter)? Do I need both or can I just add one of them? Should I be satisfied with this? I feel that the beer is too sweet right now. Primary fermentation finished almost three weeks ago.

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I strongly advise against yeast nutrients, unless you are sure that this addition will not be sensed in finished beer even if yeast will fall to eat it. Once I had a batch less than optimal due to this.

First, you can just stir gently. This may sometimes be all you really need.

Second, more reliable way is to add a packet or three (yes, three, really) of rehydrated dry yeast. With three packets, cell count should be enough to finish big beer even in unfavorable conditions. To be more specific, use pitching calculator. Then multiply by 2, because some cells won't do it in wort already with alcohol. Then use cell count from manufacturer to see how much you need.

Third option is one I prefer. Make a new beer with yeast you need. Small one, about 10-12°Blg. Nutrients, aeration, all that. As soon as you have a slurry, transfer new beer to secondary, and slurry to the stuck beer. That way, your yeast will be fresh, active and accustomed to having alcohol in solution.

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  • I was thinking about pulling out some beer from my secondary and pitching another yeast packet with some nutrients to get things going, and then putting that back into the main batch. I think though that the risk is just too great of contamination or worse, ruining the beer that I take out and losing it. Plus, I read in Ray Daniel's book that if yeast is not in an ideal environment, it will still ferment but may contribute off flavor.I swirled my fermenter a little yesterday. I'm going to give that a little time to see if I get a few more points and then bottle this weekend.
    – thekolnik
    Commented Dec 8, 2016 at 2:54
  • Adding yest to beer from secondary? But... Why? New beer allows yeast to multiply. Old one is already out of sugar and nutrients.
    – Mołot
    Commented Dec 8, 2016 at 6:22
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    I'm assuming if I add fresh beer to the current batch then that would mess up my gravity readings. I was thinking that there might still be enough sugar in the mostly fermented wort to allow a yeast with higher tolerance to get going. This would avoid messing up my gravity readings. Not going to do it though. Just going to bottle in a few days and be happy with what I have.
    – thekolnik
    Commented Dec 9, 2016 at 18:05
  • Adding pure yeast slurry is negligible for readings :)
    – Mołot
    Commented Dec 9, 2016 at 20:06
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    Worked like a charm. Got my gravity down to 1.018. Bottled on Friday. Will condition in bottles for 3 weeks. Thanks for everyone's help!
    – thekolnik
    Commented Dec 24, 2016 at 16:01
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One can pitch dry powdered yeast directly into a brew. It often works well but sometimes not. In my entire brewing career(?!?) I have never used a yeast nutrient(!?!). Some do, some don't.

I usually recommend making a starter with yeast in sugar solution as this is the easiest way to check the yeast is actually active before pitching. I have used powdered yeast that has not been active and I only discovered it some days into the brewing. If one pitches a demonstrably active yeast culture then that much is certain!

Other have also recommended a good rousing/stirring of the brew and any sediment to bring any active yeast back into circulation. Yeast needs oxygen to grow so some aeration of the wort is (at least initially) optimal. If one wants the new yeast to grow some oxygen must remain in solution. Alternatively one can pitch a very concentrated yeast starter that already has sufficient yeast to do the fermenting without the need to grow/multiply.

Of course the original wort may have had a higher percentage of unfermentable poly-saccharides (eg starch and malto-dextrins) and that is the reason the fermentation has stopped - it has run out of fermentable sugars. One way to improve this situation might be to add some pilsner enzyme to break down the poly saccharides to simpler sugars which can be fermented. That would probably require some lagering for it all to take effect and proceed to completion.

Good luck!

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  • I tried swirling a little last night and even introduced a little aeration. I didn't want to aid too much oxygen because I'm worried if the yeast doesn't start back up then I'll have oxygenated beer! Anyway, I'm going to check the gravity again after two days, and if there is no change, I'm just going to accept my result.
    – thekolnik
    Commented Dec 8, 2016 at 2:50
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It looks like you aren't the only one having this problem, however it may just be that it's finished:

http://www.homebrewtalk.com/showthread.php?t=161961

http://www.homebrewtalk.com/showthread.php?t=376552

If you wanted to be sure, you can just pitch the yeast in directly... from what I have read, starters aren't needed for pitching dried packet yeast.

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