Imperial Chocolate Milk Stout yeast choice

[jstebell]

Hello all
First off I'm big time IPA brewer. Never brewed a stout before but figured I'd give it a go. What would be a good yeast choice for an imperial chocolate milk stout with an OG of 1.105. I want it to to hit around 11% ABV. I'm looking for some residual sweetness so I will be adding a pound of lactose. Should I use a yeast that will fully attenuate and have the lactose to give it some residual sweetness. Or use a less attuanative yeast. Also what mash temp should I use. I know I should use a low mash temp to help it fully attenuate. But I want the sweetness. Will the 1# of lactose bring the body back up. This whole lactose thing is throwing me through a loop as I never added any unfermentables to a beer before. Any help will be greatly appreciated.
Cheers!! Attenuate

 

[BanginBanjo]

Assuming your doing a 5 gallon batch, the 1lb of lactose is going to add about 1.009 to both your OG and FG. So if your OG is 1.096 without the lactose, your going to need to get about 85% attenuation to get down to around a 1.014 (which is about 11% abv). Then with the lactose added in your FG is really a 1.025, which is probably in the range your looking for with an imperial milk stout.

As for yeast, you could find a strain that will attenuate to 85% and tolerate 10%+ abv, which will be tough to do along with getting the character your going to desire for this style. Id probably try to go with a WLP007 and see how far that gets you. If you mashed at 148-149 and provided optimum fermentation conditions you might be able to get close to 85% with it.

If it doesn't finish the job you could always pitch a yeast with higher alcohol tolerance and higher attenuation to finish the job.

 

[BigFloyd]

Depending on what chocolate/cocoa you use and how much, a pound of lactose may not be enough to do anything more than somewhat balance out the bitterness.

A couple of yeast options come to mind. Easiest is to rehydrate and pitch 2 packs of S-04. I did a chocolate stout with it earlier this year and it's delicious. Start the ferment at 63*F and slowly bring it up to 68*F after the first 5 days. Second option is to brew a lesser gravity beer (like a mild, bitter or an ESB) using your choice of English ale yeast (WLP002/WY1968, WLP007, etc.) and then pitch the big stout on the yeast cake after you rack off the first beer. I'd prefer to do that vs. making a massive starter.

 

[jstebell]

Thank you both,
I was thinking WLP007 or maybe WLP090. With a large starter obviously. I normally use the 090 on my big IPAs with great success normally from 1.100 all the way to 1.008 on my most recent younger clone. Dry hopping as we speek. I was planning on using 4oz nibs in the mash and 4oz in the secondary. Again thank you both as I'm very new to this style.