Fermentation Stalled after aeration and a hefty pitch.... HELP!

[ApothecaryBrewing]

So I made my first Stout recently. Recipe is:

• 10# MO
• 1.5# Flaked Oats
• 0.75# Flaked Barley
• 0.75# Crystal 60
• 0.5# Victory
• 0.5# Pale Chocolate
• 0.25# Roasted Barley
• 0.25# Rice Hulls
• 1 oz. Nugget
• 1 oz. Willamette
• 6 oz. Cocoa Powder (Unsweetened) added at 10 min.
• 20 grams US-05 (Rehydrated)
• 16 oz. cold-brewed Kona Coffee
• 2 x vanilla beans

Mashed at 154 but sank to 151 by the end of the hour. OG was 1.068 or so and it has been fermenting at around 62F for 9 days... and counting.

The coffee and vanilla beans haven't gone in yet. They are slated to go in during secondary, which I had planned to do yesterday but I took a gravity reading and the beer was still a bit higher than expect... 1.020

I figured with slightly overpitching the US-05 I wouldn't have any issues. I aerate with pure o2 and added a tsp or two of yeast nutrient during the end of the boil. All signs should point to a healthy and complete fermentation.

My questions are why did it stall? Am I overlooking something? Did the cocoa addition add to the gravity in some way? I am completely lost as to why this thing didn't get down to the expect 1.016 or so.

Please help me HBT forum users... you're my only hope.

 

[SpeedYellow]

You got 71% attenuation, so I'd say it's fully fermented.

Sounds like a nice recipe. Just remember it'll change a LOT in the first 3 months, so don't be hasty to judge it.

 

[ApothecaryBrewing]

I was expecting closer to 75% with the double pitch of US-05 but you make a good point.

Probably will let it sit until Saturday then rack it onto the coffee and beans. Thanks for the feedback!

 

[cheezydemon3]

Overpitching is NOT how you get higher attenuation.


Your beer sounds fine. Don't ruin it.

 

[aiptasia]

I agree, I think it's fully fermented. BTW, I think you did everything right. Can I ask how you are going to be carbonating it? If you're going to naturally carbonate it with the yeast in bottle or keg, let me know if you have any carbonation issues. I made a similar beer for a competition using a healthy amount of cocoa powder and I think the fat in the powder was detrimental to head development and retention.

 

[kombat]

If you let it warm up to 70-75° F, you might get a couple more points of gravity out of it.

 

[ApothecaryBrewing]

I agree, I think it's fully fermented. BTW, I think you did everything right. Can I ask how you are going to be carbonating it? If you're going to naturally carbonate it with the yeast in bottle or keg, let me know if you have any carbonation issues. I made a similar beer for a competition using a healthy amount of cocoa powder and I think the fat in the powder was detrimental to head development and retention.

I naturally carb in the bottle. Can't afford a keg set up yet. The unsweetened powder is supposed to lack the oils that nibs have that can potentially ruin the head. I used plenty of oats and barley to try and counter act this issue... I will report back when I know the outcome.

 

[wyzazz]

Warm it up in to the 70's, give it a swirl to re-suspend the yeast and see how it goes. You should be able to eek out another point or three from it.

 

[SpeedYellow]

I agree, I think it's fully fermented. BTW, I think you did everything right. Can I ask how you are going to be carbonating it? If you're going to naturally carbonate it with the yeast in bottle or keg, let me know if you have any carbonation issues. I made a similar beer for a competition using a healthy amount of cocoa powder and I think the fat in the powder was detrimental to head development and retention.

Cocoa powder has the least amount of fats possible in a cocoa product. Nibs are IIRC 50% fats. So I don't know if cocoa powder affects head, but if it does, it's probably not because of fats.

 

[ajf]

What makes you think it's stalled? You need 2 gravity readings taken several days apart to verify that fermentation has stopped.

I know that with most of my beers, the gravity is still dropping slowly after 9 days, and I ferment at a higher temperature than you, but I don't usually use US-05.

-a.

 

[homebrewdad]

You might be able to wring another point or two out... but at 71%, you may well be done. At 6.3% ABV, it's not like you are in unreasonable territory.

 

[g-star]

Looking at your recipe, you have nearly 30% unfermentables, so this beer is clearly done. Warming it up, rousing, or adding more yeast will not help.

In the future, if you want more attenuation, you need to adjust your recipe (more base malt/less roasted & crystal grains).

 

[Evan_L]

Plus you effectively mashed at 154*, even though it did drop on you over the course of an hour, most conversion takes place in the first 15/20 min. sounds to me like it's done.

 

[ApothecaryBrewing]

Thanks for the feedback all! Gonna take another reading tonight or tomorrow and move it to secondary.