OG - has fermentation completed?

[kestlemill]

Hi,

I'm trying to make a 10% ABV stout and it's been fermenting for 6 days and the yeast has totally died down and doesn't seem to be doing anything, but I'm worried that the yeast has packed in before it's finished its work. The beer doesn't taste very sweet but the OG is 1.02. Does this sound about right? (i didn't take an original reading)

Thanks for your help!

 

[sheffieldlad]

as far as i can tell you can't really calculate the abv if ou have no OG (Origional Gravity) reading.

You're FG (Final Gravity reading) is only now useful to check if fermentanion is finished by taking another reading 24 hours later. if it's the same, I'd say fermentatino is all done.

I also understand that different yeasts only ferment to a certain alcohol level before they die off.

What yeast did you use?

 

[graysalchemy]

What recipe or kit have you used? If it is an ag or extract you should get a guestimate from the ingrediants and volumes but it won't necessarily be accurate.

 

[kestlemill]

hi chaps i used Safale SO4 out of a sachet. Shed any further light?

 

[kev]

hi chaps i used Safale SO4 out of a sachet. Shed any further light?

What did you make the wort with?

K

 

[kestlemill]

I made the wort with 2kg of various different crushed malts, and 4.5kg of pale malt extract (equiv of 6kg crushed malts i think, so 8kg total)

 

[graysalchemy]

What volume of wort did you end up with?

If you can post your exact recipie and volumes and what you did then we may be able to help you.

:thumb:

 

[kestlemill]

2kg crushed malt left at 66C for 1.5 hours.
Boiled water from this together with 4.5kg pale malt extract and water for 90mins.
Final volume approx. 22 litres.
Added 1 sachet Safale So4.
Left in bucket at room temp to ferment.
Frenetic yeast activity day 2
Yeast activity zero by day 7, at which point OD reading is 1.02.

Do you think fermentation is complete?

 

[graysalchemy]

Sorry to be a pain but what were your crushed malts. We need to know if they were diastic and able to convert the starch to sugars. If there was no pale malt then it would be unlikely that you got much starch conversion in your mash.

If your malts did convert then i recon you have a beer at about 8% ish if they didn't and all the fermentables came from the malt extract then you are probably looking at an OG of 1061 giving you a beer of 5.4% at that finishing gravity. It is possible if you had a lot of unfermentables from the mash that you will have a finishing gravity of 1.020.

 

[kestlemill]

Hi again.

It was roughly:
4.5kg pale malt extract
0.5kg peat-smoked malt http://www.themaltmiller.co.uk/index.ph ... view=write
0.3kg black malt
0.8kg roasted barley
0.4kg chocolate malt

 

[Runwell-Steve]

WOW, that is a lot of Black Malt.

I would imagine your Starting Gravity would have been approx 1.090

Realistically this will only ferment down to about 1.020 so I would say it is finished.

This should give you approx 8.8% ABV

 

[graysalchemy]

I may be wrong but I don't think you would have got any fermentables out of you grains as non of them are diastic and would not produce the enzyme to convert the starch.

As a result I think you would have had a starting gravity of about 1.061 giving a beer of 5.4%

 

[kestlemill]

Holy cow I wd be mightily disappointed with 5%! an important lesson learned re og readings. Thanks for the advice I will rack it tonight.