Stuck Fermentation w/ 1056
 

After a ten year "home-brewing sabbatical", I finally decided it was time to brew a batch of homebrew 4 weeks ago. I had long ago sworn off extract brewing, so I picked up where I left off and proceeded ahead with planning out a smoked porter.

A few days in advance, I made a 1-quart starter from a small batch of ~1.030 Pale wort and some reclaimed yeast from the bottom of some Sierra Nevada Pale Ales. That went off very well - nice clean aroma - active fermentation as I came upon brewing day.

The grain bill for my single infusion mash consisted of the following:

10 lbs 2-row Pale
1.5 lb Smoked Pale
1 lb Unmalted Wheat
1 lb Chocolate Pale
4 oz. Black Patent

When all was done, I had collected about 5 gallons of 1.055 OG wort. Once cooled, I pitched my yeast, and it was fermenting away in about 24 hours. Not a crazy-active fermentation, but I chalked that up to the low-60's temps.

After 5 days I racked off to secondary and recorded a gravity of 1.040 - higher than I expected, but I just figured it was taking it's time - I could see evidence of fermentation, albeit not very lively.

Now, 20 days later, I finally get around to taking another gravity measurement - I get a reading of 1.037. Frankly, I'm not surprised as there has been little activity from the air-lock and the lack of any bubbles confirms that.

I'm unsure of what to do next - never had this happen before. Suggestions???

What was your mash temperature?

It didn't drop as much as I thought when I doughed in, so it started at about 170 but I let it sit for about 90 minutes until it dropped to 155.

Hmmm.... where to start.

1. How did you grow up your culture? You likely dramatically under pitched unless you stepped the starter up several times.

2. You racked it off the yeast way too soon. Next time, hit your terminal gravity, and then rack it off the yeast.

3. If you temperature was at 170* to start, you likely denatured most of the enzymes that convert starches to sugar. Best case scenario is that the starches that did convert are likely long-chain dextrins which are not fermentable.

1) It was a single step - 4 bottles worth of yeast dregs. I've done that before with good results, but I realize every situation is different.

2) Yea, I've just been doing some reading that seems to suggest that getting it into the secondary quickly is an "old skool" thought-process. I would have been better off stirring things up and getting it to a warmer environment.

3) In hindsight, I was concerned that the higher starting temps could have been a problem.

Thanks for the feedback.

+1 to this. 170F is typically the mash OUT temperature when you want to stop conversion at the end of the mash. If it took 90 minutes to get down to 155F your temp was really high for a long time...

+1 to #3


If you are using a cooler for a tun, try this. Add your 180°-170° water (this will change depending upon your strike temp and what the heat sink is of your equipment), wait ten minutes for the tun to warm and the water to drop. It should drop about 10°. Add your grain and stir like crazy. Wait five minutes and check your temps again. You should be around your target temp, adjust as needed. Open a beer and wait an hour.

Appreciate the input on what I should have done - good input for next time. But now let's focus on what I should do with this 5 gallon bucket of brown stuff. :confused:

It actually tastes okay as is right now, so it hasn't gotten infected. I'm thinking I'd like to make a quick ~1 gal batch - not even bother with hops - getting it going to high krausen and then pour the existing 5 gallons into it.

Think that might jump-start things?

I don't think you have any fermentables left. That's the result of the high mash temp. Just bottle that brew as a session porter and move on.

Adding amalyse enzyme to it would break down all of your long-chain dextrins. The issue with this however is that it will literally make every sugar in there ferment out leaving you with a very thin alcoholic beverage. Given the choice though between a cloyingly sweet low alcohol beer and a bone dry booze bomb, I'd choose the later.