Stalled fermentation on Muntons kits?

Ravelleman

I started a Muntons Gold Imperial Stout kit over a month and a half ago. The fermentation went well at the start then stalled a little after 3 weeks or so. After giving it a stir with a paddle it started bubbling again for a couple of days.

According the notes taken by my friend the initial SG was 1036. The gravity appears to have stalled at 1012. The box says that you can bottle anywhere from 1014 below. According to my calculations that means it only has a ABV of around 3.15%, which seems awfully low. Should I just assume that the initial SG reading was taken incorrectly?


Similarly, I have their IPA on the go at the moment. I added 1kg of dextrose to the 3kg kit to create the higher strength version as per the instructions. The initial SG was 1052 and now it's reached 1016. It stalled for a while as well but a stir with the paddle created another couple of hours of bubbling before it stopped. I stirred again yesterday without any response.

The temperature in the room where I'm brewing both has been at a constant 19-21 degrees over the last few weeks.

Krusty_Clown

I made the Muntons IPA kit recently (also with an added Kg of Dextrose) and IIRC, my SG was 1.064 (at around 22'C) and FG was 1.010, so your starting gravity seems a little low by comparison. Did you mix it well at the start?

Doesn't it mention something in the instructions about the final SG being higher, if you add the extra Kg of dextrose (like up to 1.019)? Still seems like a low ABV, given the added fermentables.

Ravelleman

I certainly thought that I'd mixed the dextrose well - with hot water as the malt extract was being added, then stirred thoroughly before adding the cold water. I noticed a few days ago that the taste of the wort was quite sweet but after the stirring and subsequent bubbling it tastes much more bitter. I certainly don't think that fermentation has stopped. I just wonder how to get it going again. Is more stirring the answer?

As for the stout, any idea what's happening there? I've tried moving the yeast at the bottom around so that it spreads around the wort evenly but there's no response. The initial SG must have been incorrect! Regardless, I'm worried about bottling this now.

Ravelleman

Any help with the stout? I think bottling will be on Thursday as it's been around 5-6 weeks since we started it.

fobster

What temperature was the SG of 1.036 taken at? Hydrometers are usually calibrated based on a temperature of 20 celcius, the below can adjust the readings once you know the temp it was taken at.

And don't rely on whether it's bubbling or not, once the reading is consistent over a few days and below 1.015~, bottle away.

http://hbd.org/cgi-bin/recipator/recipator/hydrometer.html?15074534

Ravelleman

Probably 28-30c or so. Ultimately that will work out at about 3.5% which is still low.