Brew # 21 - Juicy XPA

This brew is based on the Juicy XPA extract kit from Australian Home Brewing I purchased a while back, before I had the Grainfather S40.

Can you use the Grainfather S40 for extract brewing?

The short answer is "yes". The Grainfather S40 can be used as a 40L brew kettle, allowing you to do a full-batch (~23L) boil and add all your ingredients before transferring to your fermenter.

I did this following the method described here and the results (so far) have been superior to the half-boil method I've used for extract brewing in the past.

Ingredients

  • Black Rock Crafted India Pale Ale 1.7kg
  • Wheat Malt Dry Extract 500g
  • Brew Blend #15 1kg
  • 25g Magnum Hop Pellets
  • 25g Eclipse Hop Pellets
  • Mangrove Jack's M36 Liberty Bell Dried Yeast

Equipment

  • Grainfather S40
  • Hop spider
  • Spoon/paddle
  • Immersion chiller
  • 1/2 Whirlfloc tablet
  • HDPE fermenter
  • RAPT pill
  • Brewzilla 35L neoprene jacket

Method

  • Bring 25L water to boil in the Grainfather S40
  • Slowly add the wheat malt dry extract and Brew Blend #15, stirring continuously (didn't want anything to hit the bottom and burn)
  • Start warming the extract tin in hot water
  • Add the hop spider
  • Add the Magnum hop pellets to the hop spider
  • Slowly pour the extract into the wort, stirring continuously (didn't want anything to get stuck on the bottom)
  • After 50 minutes, place the immersion chiller and half a Whirlfloc tablet into the boiling wort
  • Attach immersion chiller ingress pipe to cold water tap and place the egress pipe somewhere it can drain (like a sink)
  • Disconnect heat
  • Remove hop spider
  • Turn on cold water
  • Stir the wort in an anti-clockwise direction (counter to the flow of water in the immersion chiller) until the wort temperature is below 30C (ideally < 25C)
  • Turn off tap
  • Remove immersion chiller
  • Test OG using refractometer
  • OG: 1.049
  • Drain wort into sanitised fermenting bin
  • Pitch yeast when the temperature of the wort is ~23C
  • Add RAPT pill to fermenting bin
  • Replace lid and add air lock
  • Wrap in 35L DigiBoil Neoprene Jacket

After 2 days of fermentation, I've added 25g of Eclipse hops (15-18% AA).

The temperature of the wort has dropped to around 15C (with -2C adjustment) thanks to some unseasonal cold weather in NSW. I think this has caused the fermentation to stall. I was expecting to hit a final gravity of around 1.012 (currently 1.016).

The Bohemian Pilsner was in the fermenting fridge, but that's now been moved into a keg for conditioning. This beer has gone into the fridge to be given a gentle push back to ~18C to squeeze a bit more out of the yeast.

In the 24 hours since I started warming, the yeast appeared to start converting again (currently SG 1.016, 66.1% att., 4.08% ABV).

After 3 days, the temp continues to rise slowly and fermentation continues. Currently SG 1.015, 67.9% att., 4.19% ABV.

Fermentation completed and the temperature was chilled to 3.5C over the course of 5 days before the finished beer was transferred to a sanitised corny keg. This was pre-loaded with a blast of CO2 and chilled to 3.5C.

Final numbers were SG 1.012, ~75% attenuation, 4.5% ABV.

Coming next...

  • Allow to condition at 3.5C for 1 week

Progress

The graph below shows the temperature (red), specific gravity (blue), and ABV (green) reported by the RAPT pill as the fermentation progressed.

Fermentation progress for Juicy XPA

Note: The RAPT pill was set with a temperature offset of -2C after I did some initial calibration with my normal thermometer.

A third thermometer probe attached to the outside of the fermenter showed a higher temperature, so I think maybe the offset is too great or maybe not required at all (the temperature at the centre of the fermenting beer is likely to be warmer than the outside of the HDPE fermenting vessel).

The Pill, nonetheless, still provides a great reference for changing temps and specific gravities.

Improvements for next time

I hadn't expected to do extract brewing again, but I think this experiment has proven that it's very easy to do with the Grainfather S40 and the RAPT Pill also makes it very easy to know what's going on. Whether I do it again or not will probably depend on the end result...I'll let you know!