Fermentation stopped early

[Chris]

I've got a Golden Ale that was in the primary for about 3 days, then has been in the secondary for about a month now. It reached 1.017 about 2 1/2 weeks ago and isn't dropping any further. Taste is fine, just seems to have stopped fermenting. Temp normally in 20-24 range, although it has dropped to 14 when I accidentally switched off the heatpad (yeah, I need to get a temperature controller, it's on the list).

 

Ideally I would just bottle it as is, but is it risky with such a high final gravity? Don't want any beer grenades in the garage. Lowest i have bottled at in the past is 1.015.

 

What are the other options, I guess pitching more yeast would work no? However I'm not that happy about leaving it on the dead yeast for much longer. I guess racking off again is a possibility, but not one I'm keen on. As I said, I am keen to have done with it and bottle. I use glass mainly btw not PET.

 

Also what would have caused this, is it my poor temperature management?

 

I rehydrate my yeast before pitching. Using S-04. Wasn't as vigorous as the last batch of US-05 i did but it was pretty good.

 

Any advice much appreciated. Cheers

[Andre Jaworski]

Sounds like too high mash temp. I've had this a bit lately as i've been playing around with mash temps. They reckon if the gravity stable for two days it's good to bottle. I have bottled beers around 1.020 with no problems.

[Chris]

It's just an extract brew, but can you explain why a high mash temp would cause this? I don't understand sorry. Would like to learn though as I plan to go all-grain eventually.

 

The bottom line sounds good though, I usually say if it's consistent over 5 days I bottle, just not bottled this high before.

[Christian]

S-04 has low attenuation compared to US-05 so 1.017 sounds reasonable. If it's stable, bottle it. I had a bottle grenade with S-04 a few months ago but in hindsight I bottled it too early (I don't usually check for stablity as I have a good feel for US-05 but I'm not so experienced with S-04).

[Chris]

I usually get about 1.013-1.015 off the same OG for S-04, which is why I was a bit concerned. Not done much brewing with US-05 so can't comment. But I agree, after 2 1/2 weeks of no change, surely it's safe!

[James Lawson]

I regularly get 1.010 with S-04. 1.017 seems pretty high. 14degC is definitely on the low side for S-04 and it tends to drop out when you do that.

 

My advice would be, if you haven't bottled it yet, to get it back up to 20degC and try and get the yeast back into suspension by swirling the fermenter (not too vigorously mind,) a couple of times a day. I'd be surprised if this didn't knock a couple points off.

 

Also, S-04 can be quick to attenuate 90% but slow to finish the last 10%, so just give it some time. Usually when I use that yeast I'm often still getting some airlock activity (which I don't think is just degassing) past the 7 day mark.

[Chris]

Thanks for that, yeah it's too late I bottled it a few weeks ago, but will remember for next time.

 

It was in the fermenter for getting close to 6 weeks, at which point I normally worry about autolysis?

 

Yep I've noticed at 7 days it can still be bubbling.

 

Under the exact same conditions using US-05 I got down to 1.008...

[jt]

I guess the next questions are

- what was the OG and

- What was your recipe ?

 

I've found the 'O4 can attenuate quite well, depending on the beer

perhaps the temperatures upto 24C have stressed it ?

[Chris]

OK looked up my data from previous brews, getting attenuation of 64.2 - 69.0% with S-04. My predicted FG based on an OG of 1.041 was 1.013 - 1.015. Have done probably a dozen brews OK with S-04 so was a little suprised at the crappy attenuation.

Recipe is just a simple extract kit job (I am just a beginner), Munton's IPA with a Brewcraft converter. 1 pkt of dry S-04 (rehydrated before pitching). Challenger, Super Alpha, riwaka hops. Target ABV 3.4-3.7. Style Standard/Ordinary Bitter (aka Golden Ale in Pom speak). Aiming at a JHB type beer (if anyone's heard of that I'll buy you a pint lol)

I do worry about the temp, yeah. Time to convince the gf I need a brew controller methinks

[Chris]

p.s. I intend to use 2 pkts of yeast from now on. Always used to but got cheap and cut it back to 1 cause it was doing fine. Hmm hindsight is great eh.

[MrC]

I wouldn't use two packs for a beer like this.  One is plenty.

[Chris]

Good to know, thanks. When would you start using 2 packets, is there a particular OG you'd start thinking you need more yeast?

[MrC]

Personally, I wouldn't use two whole packs unless the OG was around 1.100, which I did it recently for Russian Imperial Stout with an OG of 1.099.

 

I'd happily use one 11.5g pack of yeast for 20'ish L of  any beer up to about 1.070, which covers 75% of my beers. I've even been known to use 1.5 packets of yest and throw the rest away for beers around 1.080 or when I'm using old expired yeast for an experimental beer.  

 

Yeast pitching rates are only part of it for me.  Pitching rate, rehydration (for dry), nutrients, aeration, starters (if required for liquid yeast) and temp control are all important.  

 

Check out Jamil's yeast pitching calculator if you haven't already:

http://www.mrmalty.com/calc/calc.html