Oatmeal Stout Take II

I brewed an oatmeal stout as my second batch back in April 2014.  I didn't think it turned out very well which I attributed to improper yeast pitching technique.  The grain bill also seemed a bit more complicated than it should be.  For this batch I have put together my own simple grain bill which will hopefully yield me a smooth drinking beer.

I wanted to try a new hop variety for this batch that would get me a fairly substantial bitterness so I will be using Admiral hops.  I will also be trying a late hop addition of Simcoe which should be fairly interesting.

I will be re-pitching the Wyeast 1968 from my English Barleywine for this batch which will save me some money and the trouble of having to build a starter.

I'm really interested in refining my process with my new brew rig after the last disastrous brew day.  Hopefully I will learn more about how to use it from this batch.

Recipe Details:

• Grain:
• 7 lbs 2 Row
• 2 lbs Flaked Oats
• 1 lb Chocholate Malt
• 8 oz Crystal 80L
• 4 oz Roasted Barley
• Hops:
• 1 oz Admiral (Pellet, 13.1% AA) at 60 min
• 1 oz Simcoe (Pellet, 12.3% AA) at 10 min
• Yeast:
• Wyeast 1968 London ESB Ale Yeast (Third Pitch from this beer)
• Used 8 cups of slurry
• Water:
• 10 gal Spring water
• 4 gal Tap Water (in sparge)
• 1 oz Calcium Chloride
• 1 oz Gypsum
• 1 oz Irish Moss at 15 min

Process Details:

• Batch Size:
• 5.5 gal (Target 6.0 gal)
• Mash:
• 154 F for 60 min (Target 156 F for 60 min)
• Boil:
• 60 min (Target 60 min)
• Fermentation Temp:
• 65 F
• Primary Duration:
• 5 weeks
• Secondary Duration:
• NA

Results:

• OG:
• 1.052 (Target 1.046)
• Efficiency:
• 76% (Target 72%)
• FG:
• 1.006 (Target 1.018)
• Apparent Attenuation:
• 88% (Target 60%)
• ABV:
• 6.04% (Target 3.68%)

Brewing Notes:

• 6/20/15 - Brew day - 8:10 to 1:40 including setup and cleanup
• Brought 6 gal up to 200 F - took 30 min
• Transferred 1.5 gal of water via pump to the mash tun - filled the space under the false bottom.  This raised the temp to only 120 F
• Cycled the water from the mash tun to the HLT until the mash tun was at 165.  Filled the tun to 3 gal above the false bottom and then cycled
• Once temps were right I allowed the water to transfer to the grant which took about a half gal.  Topped up the mash tun to 3 gal again
• Cycled water through the RIMS to even out the temps.  Evened out at 165 F.
• Turned on the RIMS to 156 F
• Added CaCl and Gypsum to the tun
• Added the grain while the RIMS was cycling.  Stirred to eliminate dough balls
• Added another half gal of water to cover the grain more - temp in the tun settled to 158 F
• Set the cycle rate to ~1 qt per minute
• Mash tun temp fell to 152 F after the first 10 minutes of cycling.  Raised the RIMS temp to 160 F - not sure what this is going to do to the enzymes
• Measured gravity as 11.8 brix after 30 min - this is 1.046.  There is about 5.5 gal in the system at this point so this is a bit lower than the planned 72% efficiency
• Cycled for 60 min.  Had to make several adjustments to the pump rate out of the grant to get it to match the flow out of the tun.  I also stirred the mash several times as it turned out the water level wasn't above the grain bed and the wort was pooling which was likely screwing up the heat distribution and draining.

• Measured the gravity as 13.2 brix after 60 min - this is 1.053 which is probably about 76%
• Heated 4.5 gal of spring water and 2 gal of tap water up to 200 F for fly sparge - took 25 min
• At the end of the mash I turned off the RIMS, put the valentine arm in the upright position, and pumped all the grant volume back to the mash tun.  I then pumped an extra half gal of water from the HLT on top of the grain bed.  I setup the autosparge to a height a little above the current level.  I then turned on the fly sparge at a rate of 1 gal per 8 min, setup the valentine arm to drain at that liquid level, and pumped from the grant, through the RIMS, to the kettle at the same drain rate.  I used the RIMS to heat the wort to 185 F during the drain

• After collecting ~2.5 gal of wort the gravity of the runnings in the grant were 14 brix
• After collecting about 5 gal the runnings in the grant were at 12 brix
• Ran out of sparge water so added 2 more gal of tap water to the HLT - heated it while sparging
• Measured gravity after collecting a couple more gal as ~2 brix so I stopped collecting (as this is ~1.010 SG) as I didn't want to risk extracting tannins.  I had collected about 7.5 gal at this point so I added 2 more qt of tap water.  Gravity was 8.8 brix at this volume which is 1.035 which would be ~74% efficiency
• Brought to a boil - took 20 min
• Added 60 min hops after hot break subsided
• Added irish moss at ~15 min
• Added flavoring hops at ~10 min

• Added wort chiller to sanitize just prior to flameout
• Chilled down to 65 F (was as low as it would go) took 20 min
• Drained to fermentor - allowed cold break and hops to go over as well

• Collected 5.5 gal of wort
• Added 8 cups of yeast slurry to the beer
• Put in fermentation chamber set to 65 F
• 6/21/15 - The beer was bubbling vigorously the next day
• 6/26/15 - Moved the beer out of the chest freezer to cold crash another batch
• 7/28/15 - Bottled ~5.5 gal with 3.5 oz of priming sugar - got 53 bottles of beer out of the batch.  The gravity was measured as 1.006 which was much lower than I was hoping for.  It's a pretty smooth beer - it might end up more like a black IPA than an oatmeal stout with the dry finish though.
• 9/26/15 - Tasting Notes - Complex and interesting beer with combination of roast malt, firm bitterness, interesting hop flavoring, and expressive/fruity yeast.  The low FG, and dry finish, make this a bit of a rougher and more bitter beer than I'd had in mind when I planned the recipe.
• 11/8/2019 - Drank the last one of these tonight.  It was still very tasty.  Still had a good amount of hop bitterness and the malt flavor was still nice - very roasty and quite dry.

Lessons Learned:

1. Brew day went much smoother today but took a long time (5.5 hrs).  I think I could shave quite a bit off this time in the future though.
2. Warming the mash tun was tricky for me.  I think being able to cycle back into the HLT until the temps are good would be my best bet for heating the mash tun quicker.  I need to add a return valve to allow for that connection.
3. Had good efficiency on this batch but my pH was probably off.  Being able to set the pH to optimal values would be a good thing for efficiency purposes.
4. Top up the mash tun with a layer of water over the grain bed for recirculation next time.  This will hopefully allow the heat to more evenly distribute through the grain bed.
5. Heat 8 gal of sparge water next time to ensure that there is enough to collect the pre-boil volume.