stuck fermentation advice?

[jamsomito]

Hi all. This is my first time posting, but I been a long time lurker. Love these forums!

This is my 3rd ever brew. Its a brown sugar molasses brown ale with maple syrup added to the primary. So far its been my smoothest batch ever. Really excited about the results.

However, the recipe called for maple syrup to be added when fermentation started to die down. OG was 1.064, after a few days it slowed, took another gravity reading and it was 1.026. Dumped in the maple syrup, sealed it up, and it never fired back up again. The recipe said it would ferment vigorously for a few days but its dead as a doornail right now.

Here's my theory. My apt is 78 degrees and set to 85 when I'm not here. So, I put it in a tub of water and tried the pitch a couple frozen nalgenes in per day. I think I put too much ice in and the yeast went dormant, though I never checked to see how low the temps got. They were never above 73 though as I always read it when I put the ice in.

So what do you think? I'd like this to be bottled before the end of July so if its stuck I'd like to do something soon. Any advice is appreciated. Thanks all!

 

[KepowOb]

Someone else can probably chime in with more thorough knowledge... But I don't think an ice bath is going to get your temps too low for fermentation. Obviously it depends on the yeast style were using, but really you'd have to get it down into the low 50s, and have it stay there, at the very least.

I think what is more likely is that it was a bit on the warm side and the yeast went wild and finished up too soon.

 

[aiptasia]

Stuck fermentation is usually related to underpitching yeast on wort with a lack of yeast beneficial nutrients and oxygenation. If you want to break the 1.020 hump on big gravity beers, I would suggest that:

A) You pitch the proper amount of yeast. This requires the use of a 2-4 ml starter or pitching multiple vials/packets/smackpacks of yeast depending on how high the OG is.
B) You add yeast nutrients to encourage vigorous and healthy yeast reproduction which translates into a vigorous and healthy fermentation.
C) You oxygenate your wort right after you pitch your yeast. Remember, yeast need oxygen in the first 24-36 hours after pitching to eat sugar and multiply before they get to work making alcohol. Initially, a high saturation of oxygen in your wort is beneficial and can be achieved through shaking up your wort for about five minutes just after pitching yeast or directly injecting your wort with pure O2 for one minute.

Also, just because you tossed in some more sugar and didn't notice any airlock activity doesn't mean the fermentation isn't happening. The only way to be sure is to take gravity readings. Did you take a gravity reading just after putting the maple syrup into the beer? Did you take 2-3 readings a week or so later to see if there's still fermentation going on? The only way to tell if the fermetation is actually done is by gravity readings, not airlock activity.

 

[two_one_seven]

That is 2-4 Liter starter correct? Agree 100% otherwise.

Warming and rousing the yeast is first option if gravity hasn't moved.

I will add that you can try re-ptiching yeast. I haven't personally had luck doing this but others have. It will work better with lower alcohol levels. Yeast dislike alcohol, but they build up a tolerance to it. The fresh yeast won't have that tolerance.

 

[jamsomito]

Wow, thanks for the great advice. You're all probably right. Warmer temps, faster fermentation, not stuck. I took a reading today (1.5 days after adding maple syrup, 4 days total in primary) and it was at 1.015, so it's clearly still going.

A couple questions - can someone point me to where I can find how many gravity points 12oz of maple syrup will add to a 5gal batch? I've only found indirect references for different amounts...

Also, I really want this to end up a sweeter beer. What's the best way to prevent over-attenuation? Just keep pitching in nalgenes of ice every day into my cooling bath?

Here's some pics as a thank-you . The wort still tastes great (though not much maple syrup... oh well).

 

[two_one_seven]

Looks like you are fighting yourself. The lower the final gravity the dryer the beer. The higher the final gravity the sweeter/more mouth feel. You don't want to push the yeast to finish if they are still working. 1.015 is getting down to the range of final if you want a product with more mouth feel. Take a reading a couple of days in a row and if it hasn't change your done.....bottle keg or whatever you do.

I use the recipe builder at this website....but there are a ton of other good ones out there. You can calculate the effects of different additions.

http://www.brewersfriend.com/

 

[HeyYou_BeerMe]

Hey, just curious how this one turned out, if you're still hanging around.

I just started a maple ale this week, and probably added too much ice to my top-up. I'm guessing the yeast may lock up a bit for the first 24-48 hours, then start doing its thing. Has that been the general experience of the other brewmasters here?