New Zealand IPA - BrewZilla Brew Day

Here's the rundown for our New Zealand IPA BrewZilla brew day!

Water

We like to get a head start on brew day by collecting and adjusting our water the day before. We adjusted our mash and sparge water with calcium chloride and calcium sulfate in order to hit our desired water profile (as per the recipe)

We collected our required volume for mash and sparge water in our BrewZilla and Digiboil vessels.

Grain

We measured out 5.7kg of regular 2-row ale malt as per the recipe

Plus another 300g of munich malt

The grain was then crushed with our Keg King 3 roller mill. We use a fairly coarse crush in order to ensure decent water flow for recirculation and sparging.

First Mash pH Adjustment

We added approximately 3.75mL of phosphoric acid to the mash water prior to adding the grains in order to lower the pH of the mash into the desired range of 5.2 - 5.6

After mashing in and letting the grain bed settle for 10 minutes, we began recirculating and then took our first reading - 5.05 which is unusually low.

We gave the grain bed a good stir, then took another sample for a reading which gave us 5.29. Much better. We then added another 2mL of phosphoric acid to  help drive the pH a little closer to 5.2

Sparge Water pH Adjustment

Now that the mash was underway, we turned our attention to the sparge water and added a small amount of phosphoric acid to it as well to help get the pH into the 5.2 - 5.6 range as well.

Mash Recirculation

Even with 6kg of grain in the BrewZilla, we were seeing pretty good recirculation. We attribute this to the coarse crush we use now that we're milling our own grains for brew day.

After another couple of small pH adjustments, we got the pH down to 5.24 - close enough to the target of 5.2

The temperature probe we normally appears to have a faulty probe so was giving wildly inaccurate readings so we're back to measuring the mash temperature from the top of the grain bed. 64.8°C is close enough to the target of 65°C.

Sparging

After an uneventful 60 minute mash we lifted the grain basket and began sparging with the water from the Digiboil.

We continued sparging until we reached our desired pre-boil volume of 28L

The Boil

While waiting for the BrewZilla to come to a boil, we began measuring out our first hop addition of Warrior for bittering.

We also took a pre-boil gravity reading of 1.050 - a couple of points lower than the expected 1.052

Pre-boil pH reading of 5.26 shows that our pH adjustments are still on track and no further adjustments are necessary.

Some hot break beginning to form on top of the wort just before reaching a boil.

Rolling boil underway!

We then measured out the remaining hop additions

At the conclusion of the boil we whirlpooled for 20 minutes with another hop addition before chilling the wort and transferring to the fermenter.

We took another gravity reading which gave us 1.060 - a couple of points higher than the expected 1.058, and suggests our pre-boil gravity reading was indeed a couple of points low.

Yeast Pitching

After leaving the fermenter in the fermentation fridge overnight to chill down to pitching temperature, we then added 2 packets of US-05 dry yeast. Fermentation was underway within 24 hours.

Dry Hopping

On day 5 of fermentation we dry hopped with Motueka and Rakau hops (as per the recipe) using our hop bong.

Final Gravity Reading

After 1 week of fermentation we took a sample for tasting and gravity evaluation which gave us a reading of 1.013. Exactly as predicted based on the original gravity, giving us 6.2% ABV.

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