Secondary Fermentation

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Rampage

Junior Member
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Nov 15, 2016
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Location
Algarve Portugal
Hi All

For my latest 100 litre brew I followed an Old Peculiar recipe. OG was spot on at 1058 and rapidly fell to just above 1020. As the target was 1015 I left it in the FV for a while longer and ensured a brewhouse temp of 18-20C. However, even after 2 weeks in the FV the SG would not go below 1020. So I decided to transfer to the maturation tank where it has been for 3 weeks. I decided to do some secondary fermentation in the tank (rather than in bottles) so added caster sugar (400g). There has been no activity in about 4 days and the SG is still 1020. I plan to leave it alone for another 3 weeks before getting seriously worried. Any additional advice as to what to do? Should I add some yeast to the tank to try to encourage further fermentation?
 
There is usually plenty of yeast left floating about in a brew to easily deal with secondary fermentation. (Even after 10 weeks in a fridge my lager carbonated last year with no added yeast.)

I have just made a Light Ale which I mashed and sparged at 72-75 degrees. After two weeks the FG was at 1.016 which I figure is caused by the non-fermentable sugars that are apparently produced at higher temperatures. (They give the brew sweetness at the expense of alcohol.)

Did you by any chance mash and sparge at a higher than normal temperature?

Another cause could be that the yeast has just run out of oxygen and therefore cannot continue the fermentation. On another Thread I had a discussion over a phrase that I read somewhere to the effect that you should "Beat a stuck ferment as if it owed you money!" in order to re-oxygenate the wort.

The discussion was mainly "What is in the FV?" Is it "wort" (which needs oxygen) or is it "beer" (which shouldn't be oxygenated).

Personally, if it hasn't met the expected FG I consider it to be "wort".

Hope this helps! :thumb:
 
im too lazy to check if 2g per litre is significant enough sugar to effect a noticeable change in gravity, but if it is and the 400g addition has been consumed to drop the gravity back down to 1.020 that would indeed indicate the yeast are both alive and active. And 1.020 is your FG!

O2 beating in at this stage is contrary to my understanding, Im far from expert but from the little reading ive done on the subject, yeast may require 02 for population growth, but its not crucial for the production of ethanol?

That said I would be tempted to perform a test with a litre or so of the brew, decant it into a big 2l pet bottle crumple the bottle to remove most of the air and seal it up and shake the hell out of it to agitate out any co2 dissolved in it. then open the bottle and crush it to push out most of the co2 and then uncrumple it to suck in some o2 rich air. seal and shake again to introduce o2 into the brew. again release any pressure and reseal and leave for a few days If it then drops closer to your expected FG I recant my objection above and will get me coat ;)
 
Hi All

For my latest 100 litre brew I followed an Old Peculiar recipe. OG was spot on at 1058 and rapidly fell to just above 1020. As the target was 1015 I left it in the FV for a while longer and ensured a brewhouse temp of 18-20C. However, even after 2 weeks in the FV the SG would not go below 1020. So I decided to transfer to the maturation tank where it has been for 3 weeks. I decided to do some secondary fermentation in the tank (rather than in bottles) so added caster sugar (400g). There has been no activity in about 4 days and the SG is still 1020. I plan to leave it alone for another 3 weeks before getting seriously worried. Any additional advice as to what to do? Should I add some yeast to the tank to try to encourage further fermentation?

What yeast did you use ? Have you calculated the apparent attenuation relative to what the manufacturer says it should do ?

I suspect that 1020 is your FG ... particularly if the yeast ate up the extra white sugar you put into the brew. And Old Peculier is meant to be a thick brew anyway, there will be lots of non-fermentables in there from the roasted malts.

Does your conditioning tank pressure up ? I don't see the logic of adding priming sugar before bottling
 
What yeast did you use ? Have you calculated the apparent attenuation relative to what the manufacturer says it should do ?

I suspect that 1020 is your FG ... particularly if the yeast ate up the extra white sugar you put into the brew. And Old Peculier is meant to be a thick brew anyway, there will be lots of non-fermentables in there from the roasted malts.

Does your conditioning tank pressure up ? I don't see the logic of adding priming sugar before bottling


I had once a very similar problem and it was because my conditioning tank pressure was not correct... Could be a good idea to check.
Let's hope it's getting better
 
I would do this to get a protective layer of co2 over the beer whilst conditioning.

Okay ... totally logical ... but I tend to get the beer out of my oxygen permeable plastic buckets as fast as I can ... within reasonable limits of course.
 
Thanks for all your feedback. Yeast used was 5 x 11g bags of dried Danstar Windsor, rehydrated before pitching. Mash temperature varied between 65 and 70C over 90 minutes. Sparge water was at 76C. My maturation tank is a stainless steel pressure tank so I was hoping to get the CO2 dissolved in it during secondary fermentation so I could drink it straight from the tank to save bottling. The sugar to liquid volume ratio was around 5g/l, which is indicated to be suitable for most English bitters/ales. I have filled a couple of bottles to more easily monitor progress so I'll see what happens over the next few weeks.
 
The technical blurb says it is a moderate attenuating yeast and it doesn't ferment maltotriose ... so 65% to 70% attenuation looks about right.

The last brew I did with Windsor dropped from 1044 to 1014 = 68% attenuation.
 
The technical blurb says it is a moderate attenuating yeast and it doesn't ferment maltotriose ... so 65% to 70% attenuation looks about right.

The last brew I did with Windsor dropped from 1044 to 1014 = 68% attenuation.

Yep, Windsor is a fairly low attenuating yeast, I've used it before in a mild that I wanted to finish high and it did just that.
 
Yep, Windsor is a fairly low attenuating yeast, I've used it before in a mild that I wanted to finish high and it did just that.

I reckon it is my favourite dry yeast ... for brewing British style real ale, which is my overall objective. :thumb:
 
Hi Gents. Since last post the fermentation gods have done their stuff and the OP has turned out absolutely beeeaaauuutiful. Thanks for your input on attenuation as I had not appreciated that aspect of yeast activity until then. Had a brew day yesterday - Hopback Summer Lightning but with a post boil hop addition of New Zealand Riwaka hops, which will hopefully lend a little citrus flavour to the beer now that sunny weather is approaching here in Algarve.
 
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