Incomplete Fermentation-Help?

[HopSong]

So, my son gave me a MoreBeer Rogue I2PA extract kit for Christmas. Thanks Brian. I was looking forward to a nice double IPA.

My OG was about 10 points higher than the spec sheet. Was supposed to be 76-80 and came in at 88. I've never had this kind of problem.. but, I've never done a beer with this high a gravity.

I made a 1 liter starter using DME and a vial of WLP001. It started out like gangbusters and i had the initial fermentation temps at 64* in a water bath.

7 days later the SG was at 40 and raised the fermentation temp to 67*. At 12 days it was at 26. At day 20 it was at 1.022. And that's were it stayed even after I raised the temp to 70*. I kegged it there and it did have a sweet taste. Duh. I even pitched more WLP001 1st generation hoping it would restart. Nope.

So, I went to my LHBS and talked to the expert. He suggested buying a vial of a yeast that would be good up to about 18%. Just dump half of the vial of the dry yeast into the keg.. no need to rehydrate. A week later.. Nada.. it's still at 1.022.

Sooooo, any further hints from the gallery? I can drink it like it is.. Kinda like some of the brews from Lagunitas.. Good beer but generally sweeter than some of the other local breweries.

Oh, one further point. The room stays between 67 and 70*.

 

[mrbean]

You are having a very common problem. The only thing that has worked for me so far is to put the wort onto a new yeast cake from another batch that fermented properly.

 

[Denny's Evil Concoctions]

That is giving you an apparent attenuation of 73.4%. That seems pretty good for a high gravity beer and technically within range for this yeast.

From Whitelabs: Attenuation 73-80%

 

[jalmeida]

I have been told that 8% and higher ABV beers perform better with yeast nutrients. That being said, I made a 9.5% IIPA that I forgot to add nutrient to that finished out perfect. So what do I know... But the other thing to consider is the type of yeast used. Some yeast do not like any higher ABV beers.


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[BigFloyd]

So, I went to my LHBS and talked to the expert. He suggested buying a vial of a yeast that would be good up to about 18%. Just dump half of the vial of the dry yeast into the keg.. no need to rehydrate. A week later.. Nada.. it's still at 1.022.

Not such good advice from an LHBS "expert". What did he give you? Champagne yeast like EC-1118? At that point in the process, if it's truly stuck, the only way adding dry yeast is going to do much of anything is if you rehydrate it, make a small starter and pitch it at high krausen.

1.022 isn't out of the ballpark for a fairly high gravity extract batch. Plus, that 1L starter was an underpitch for a 1.088 beer. You pitched 140-150 billion cells when you should have had at least twice that.

 

[tooldudetool]

How did you oxygenate the wort? At higher gravities oxygenation becomes much more important for the yeast to stay active and finish the job, especially in a high alcohol environment. I use pure O2 and a diffusion stone, and on beers over 1.080 I even give another 1 minute burst of O2 8 hours after pitching. Also as mentioned earlier, with extract brews it can be really hard to get the beers to finish dry. With all grain you have the option of mashing lower and minimizing crystal hops to get it to finish out low, but with extract they usually use a bit of carapils in there, and you have no control over their mash temperature, there are many threads about extract brewers unable to finish below 1.020. I think its a bit crazy to pitch yeast three times on a single beer to try to get it to finish lower.. that gets expensive and pretty yeasty! As mentioned above, you also underpitched, which doesn't help either...