Troubleshooting a Zymurgy Cherry Choc Stout

Brewing Processes
1

So last weekend we made the Cherry Choc Stout from Zymurgy and didn’t come close to either OG or FG. I’ve been all-grain brewing for over 2 years and this year we’ve made almost 200 gallons! Since we got our grain mill over the summer the last 20 batches have all been over 75% efficiency and we usually come within a point of our FG. With this stout we did a ton of new things and just wondered if anyone sees any big no-no’s. We’re mostly concerned with our horrid FG. I’d really like to not repeat this mistake. Estimated OG was 1.077 and we got 1.062; estimated FG was 1.019 and we got a whopping 1.038 (after 8 days fermenting)! Here is the list of new stuff that could have caused problems.

*high mash temp of 158F
    *6 lbs. of caramunich I and chocolate dark malts in 17 lb recipe
    *50 min mash
    *batch sparge (only done this twice)
    *5 ounces Ghiradeeli Bakers Choc in mash and 5 in boil at 15 minutes
    *kind of a lower boil this time; not sure why
    *3/4 lb lactose at flame out

2

I would think that the high mash temp and 6lbs of caramunich were the biggest problems with the high FG.  Also give the beer a couple more days and it might drop some more.

3

I get the high mash temp - probably won’t do that again - but can you explain the problem with caramunich and the FG? Did the starches not convert or are there none there to convert?

4

I don’t think either of those things speak to the low OG just the high FG. Low OG says, crush, mash pH, loss due to deadspace in tun or an error in the recipe.