Our latest brew day sees us bring our Liquid Daylight Munich Helles to life. Our second batch using liquid yeast. Read on to see how it all went.
Yeast Starter
A few days before brew day we made our first yeast starter as the liquid yeast we had was now a month or so old so we wanted to make sure it was ready to go.
We measured out 200g of extra light dried malt extract and added it to 2L of water which was then boiled for 20 minutes.
The specs from the bottle the liquid yeast was stored in.
Water Prep
The night before brewing we collected our strike and sparge water into our BrewZilla and Digiboil units and added calcium sulphate and calcium chloride to reach our desired water profile.
Milling Grains
We opt for a fairly coarse crush with still gives us decent efficiency but allows for good water flow for recirculation during the mash and when sparging.
After mashing in the grains we hit our initial mash temperature target of 63°C which we held for 30 minutes.
View of the mash - a relatively light grain bill meant it wasn't particularly thick which made it easy to handle.
After approximately 10 minutes from mash in, we took our first pH reading which was unusually low at 5.10. When this happens we always give the mash a good stir, wait a few minutes then take another sample.
And this is why. The second reading came in at a much more expected 5.39. Slightly higher than our desired target of 5.3
We adjust our pH using phosphoric acid so we started by adding 1mL to the mash.
Our next pH measurement was spot on target at 5.3
After 30 minutes we ramped the temperature from 63°C to 69°C as per the recipe.
Recirculation of the wort during the mash was good, with plenty of water flow and no backing up.
We took another pH reading towards the end of the mash which came in at 5.27 - a slight drop from the previous reading but still perfectly acceptable.
Another shot of the mash late in the piece.
After the 60 minute mash period had elapsed we ramped the temperature to 75°C for a 10 minute mash out step.
You can see the mash starting to clear up right at the end.
After the 10 minute mash out step we lifted the grain basket to begin sparging.
Water flow with the sparge was also good and was completed in around 10 minutes.
We sparged until hitting our pre-boil volume of 28L.
The BrewZilla is now set to HH to bring it to a boil. Once we hit the high 90's we could see hot break starting to form.
Pre-boil pH reading came in at 5.28.
Conventional brewing wisdom suggests that the pH should drop during the boil but in our experience this has never happened. Let's see what happens this time around.
Last thing to do before reaching a boil is to measure out our first of only 2 hop additions. First addition is 40g of Hallertau Mittelfruh - a classic German noble hop.
We also measured out 5g of yeast nutrient to be added later on in the boil.
Plus half a whirlfloc tablet to aid in clarifying the wort and finished beer.
We also measured out our second, smaller hop addition of 12g of Hallertau Mittelfruh.
With around 10 minutes left in the boil we took another pH sample which showed a fairly significant rise from 5.27 to 5.47.
We're unsure why this happens to us when everything we've read suggests the opposite should be happening. We like a post-boil pH of around 5.1, so we began adding phosphoric acid to help bring the pH back down. We started with 0.5mL.
Our first acid adjustment brought the pH down to 5.34. So we added another 0.5mL.
Bingo - 5.11 is as close to 5.1 as we need so no more adjustments from here.
We began chilling the wort with our standard immersion chiller, and took our post-boil sample for gravity reading which came in at 1.049, a single point higher than expected by the recipe.
After the wort was chilled to around 20°C (since that's as close as we can get because of the temperature of our town water we use for chilling), we transferred to our Apollo Titan fermenter.
A trusty floating hydrometer reading showed our digital reading was pretty much spot on, confirming a starting gravity of 1.050.
We moved the filled fermenter into our fermentation fridge and left it to cool to our pitching temperature of 10°C overnight.
We couldn't tend to the fermenter until the next night when we needed to oxygenate the wort prior to adding the yeast.
We use our trusty Spike Oxygenation Kit to achieve this.
We hook up the carbonation stone to our sight glass then attach the gas line from the oxygenation kit to it.
And finally, after decanting a litre or so of the clear wort from the top of the starter, we swirled the rest to get the yeast back in suspension and dumped it into the fermenter.
Because of the relatively low fermentation temperature, it was slow to get going but we had initial indications of fermentation activity after approximately 24 hours.
Stay tuned to see how it turned out!
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