Dark Chocolate Sour

With my typical 70% efficiency I am leaving quite a bit of sugar in the grain that's getting thrown away.  With a big beer that 30% amounts to enough gravity points to make reasonably potent small beer if one is inclined to do the work to get it via a parti-gyle mash.  Normally I am not inclined but today I decided to do it using the grain bill for a Bourbon Barrel Chocolate Imperial Coffee Stout.  I'm going to make a sessionable sour chocolate stout with it.

I have never had a chocolate sour beer before but there are a number of breweries that make them.  I have had Tart of Darkness from The Bruery which combines roasted and sour flavor in a pleasing package.  This gives me confidence that this experiment could work.  I will use some of the yeast cake from Flanders Red 1.2.1 to ferment this beer.

I don't have any extra hops to use for the beer so I am going to boil in the unwashed kettle used for the previous beer which will still have the hops from the last batch.  This recipe doesn't really call for any hop bitterness so I'm sure this will be fine.

I'll be taking first runnings and one batch sparge for the big beer.  My one concern is that the remaining sugars in the mash may not be easily extracted.  In order to get a bit of insurance I will be adding about 3 lbs of pale malt to the mash before parti-gyling this one.  I am hoping the gravity will end up in the 1.03s somewhere.  I'll be fermenting and aging this beer in a 5 gal better bottle.  I'm going to shoot for 4.5 gal to give myself enough head space.

I'll probably look to age this beer for a year to a year and a half.  This beer could be a good candidate for adding fruit if it doesn't end up getting very sour from just the sugar in the grain - raspberries could be a good match for this.

This is basically a free beer so if it turns out to be a failure I won't be that disappointed.

Recipe Details:

• Grain:
• 3 lbs 2 Row
• Grain bill from Bourbon Barrel Chocolate Imperial Coffee Stout
• Hops:
• Spent hops from Bourbon Barrel Chocolate Imperial Coffee Stout
• Yeast:
• Wyeast 3763 Roeselare Ale Blend (2nd pitch Slurry)
• Water:
• 6 gal tap water
• Extras:
• 2 Tbsp of Hershey's Special Dark Chocolate Powder at 5 min

Process Details:

• Batch Size:
• 4.5 gal
• Mash Temp:
• 152 F to 145 F for 90 min
• Boil:
• 1 hr
• Fermentation Temperature:
• Ambient Basement Temps (60 to 75 F)
• Primary Duration:
• TBD (12 to 18 months)
• Secondary Duration:
• TBD

Results:

• OG:
• 1.036
• Efficiency:
• NA
• FG:
• TBD (Target 1.004)
• Apparent Attenuation:
• TBD (Target 89%)
• ABV:
• TBD (Target 4.20%) 

Brewing Notes:

• 3/29/15 - Brew Day - 12:30 PM to 2:45 Including Cleanup
• Added 2 row to the mash tun after running off the sparge from the previous beer
• Added 3 gal of 185 F strike water - temp settled out at 152 F
• Let it mash while I completed the previous beer - this took 90 min - Mash ended up at 145 F
• Mashed out without a vorlauf - collected 3 gal of wort
• Added 3 gal of cold tap water as a batch sparge, stirred, and drained
• Ended up collecting 6.25 gal of wort
• Brought to a boil - took 20 min

• Boiled until it got down to 4.5 gal
• Added cocoa powder at 5 min
• Put the chiller in to sanitize at flameout
• Chilled down to 60 F - took 6 min
• Measured gravity as 1.036.  The beer has a pretty strong chocolate flavor.  No hop flavor at all which shouldn't be surprising.  The beer isn't really that sweet.  Hopefully I ended up getting quite a bit of starch that will keep the souring bugs happy over time
• Transferred to better bottle with a siphon hose
• Pulled yeast off the bottom of my Flanders Red 1.2.1 with an auto-siphon
• Left down in the basement with a tee shirt covering it to protect it from the sun.  I will plan on a gravity sample/taste test in a month
• 3/30/15 - No foam on the surface but the airlock was bubbling this evening
• 5/16/15 - After a month and a half, I checked the gravity which was all the way down to 1.002.  No sourness or funk have developed yet - not sure they are ever going to as low as this is already.  It's a pretty watery/weak beer - it definitely needs something else going on.  I'll give it a few more months to see what happens to it.
• 9/13/15 - Transferred the cherries from this Berliner Weisse to the beer.  The cherries were falling apart from their aging the the previous beer but probably still have a bit of flavor to impart.  We will see.
• 1/15/6 - Added about a liter of DME based wort that had been souring with my culture of Lacto Brevis.
• 3/6/16 - Added another liter of DME based worth I'd been using to feed my Lacto culture.  I'll need to give this beer another try some time soon.  I had a Chocolate Gose in AZ last weekend which was as interesting as I thought it might be.  Was a good combo.
• 4/17/16 - Tasted a small sample of the beer.  The lactic acid culture I added has made the beer plenty sour.  Still hasn't developed any of the rich flavors I would expect from Roeselare.  I'm thinking this one is as good as it's going to get and is ready to bottle.  The sample had a lot of cherry fruit solids in suspension.  I will rack it off the cherries into a bucket fermenter and then cold crash it here in the next couple weeks.

Lessons Learned:

1. Doing a parti-gyle really wasn't that much more work to get another beer and it's pretty cool to have a free beer to experiment with.  I will definitely look to do this again in the future.  I think I could get a reasonable projection of the OG if I were to plan ahead next time.