Incomplete fermentation -fix?

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sjp770

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I brewed a pale ale and made the mistake of just thinking two weeks was enough time without checking. So I cold crashed to 4c then racked to kegs. When I did this I checked the FG and it was 1.018. I've sampled the beer and it tastes more like a fruit juice than a nicely hopped beer..

Now that it's chilled is there any way to fix it? As I keg and use CO2 to carb no extra sugar was added.. I'm wondering if I can transfer from the keg to a secondary fermentation vessel and add more yeast.. and if so at what temp to try and recover this 37L of beer .. it does taste nice but not like a beer..
 
Yes there are fixes, problem is they divide in to two groups
The yeast failed to ferment all the sugars - probably down to yeast abuse
The yeast did ferment all the fermentable sugars - probably only applies to someone who is all grain brewing and not doing a very good job of it.
Or If the recipe contained lots of Maltodextrin or Lactose it would be possible for a kit brewer to finish that high.

If there are fermentable sugars that the yeast hasn't used, adding more yeast under the right conditions would fix it. Be worth knowing why it failed the first time. A reasonable pitch of healthy yeast should finish fermenting in a week, for the brew to have sat there for two weeks and still not done the job means wrong conditions mostly temperature, not enough yeast, unhealthy yeast (ie badly made starter), poor aeration. A combination of more than one of the preceding.
To test if there are fermentable sugars, about half fill a jar with beer 100-200mL more than enough for an hydrometer reading) , cover and allow to warm to ambient, add a fair amount of dry yeast (1g or so), if its fermenting in a couple of hours - half a day allow to finish and measure new FG.

Doing the same "Fast Ferment Test" will tell you if there are no fermentable sugars, FG wont change. Mainly caused by mashing way too hot or adding too much unfermentable sugars/adjuncts.
In this case about the only option would be to add some dry enzyme. Problem is you might end up going too far the other way and getting too dry.

Which ever way you go, its important to avoid picking up too much oxygen when you transfer back to the fermenter, allow it to warm some, try to arrange a closed transfer to the fermenter, remember the yeast wont be able to reproduce much with low oxygen so use a healthy pitch of a good clean fermenting Ale yeast either with or without Dry Enzyme.

Be well worth having a look at your processes, especially mash temperature, and fermentation temperature.
Also look at you yeast, are you using enough, is it healthy, if you are reculturing or making starters - think through your process as something taint right!.
Mark
 
I think the mash got away from me, I have it recirculating through my HLT and I set my temp controller but I needed to click once more to save the new temp.. does this mean the sugars might not be fermentable? I'll try the jar method today.. will baking yeast prove the point just as good for the test?
 
Maybe, if your brew is within the alcohol tolerance range of the yeast, probably most any yeast would do.
Not knowing your OG and the alcohol you have, nor the alcohol limit for baking yeast, I'd be guessing.

Best bet would be a cheap sachet of kit beer yeast (probably Mauri 514). Yes if you mashed too hot its a good chance you wont have much in the way of fermentables, just lots of soluble starches and dextrin's, the option of adding some dry enzyme will chop these down to fermentable sugars.
Note that I have seen beer hit 1.000 with dry enzyme, again a question of what else is in the wort. Again I'm guessing but for most AG beers 1.004 give or take is more likely.
Mark
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So... Being keg and the fact my Chronical 1/2bbl fermenter is leaking at the lid I didn't pressurize and transfer through filtration this time.

I think that there was too much hops at the base of the keg. So I got a lovely fruity taste but you wouldn't want that for all of your beer.

Yes, I didn't hit the FG I wanted but the beer is actually good. I won't bother with dry enzyme or trying to get it to ferment more. Thanks for all the info, it will help me next brew as I now know the issues with over shooting your mash temps.


It's all a learning process after all.
 

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