Monday 15 January 2024

Munich Helles - BrewZilla Brew Day (from Hell)

Our latest brew day for our Munich Helles recipe was one of the more challenging ones we've faced for sometime. Although nothing major or catastrophic happened, it certainly didn't go as smoothly as most of our previous brew days, although this can certainly be attributed to some new equipment and processes we (attempted) to implement. Here's how it went.

Grains, hops and BrewZilla ready to go

We started things out in the usual fashion with our mash and sparge water adjustments. These types of beers is don't typically require big adjustments (assuming you're source water is decent to begin with) and will usually contain low amounts of the key minerals we normally look at when brewing (like chloride, sulphate and calcium).

This was our first brew with our new KegLand RAPT Bluetooth thermometer. We're not particularly interested in it currently for it's bluetooth or logging functionality, bur rather for it's long probe so we can more accurately monitor our mash temperature from the centre of the grain bed. We had our strike water set to 69°C so we would hopefully hit our 65°C mash temperature target after doughing in with our grains.

69°C strike water temperature

Speaking of doughing in - we managed to accidentally spill some of the grain when adding it to the strike water, which seemed innocuous enough at the time, but was perhaps an early indicator of things to come. Although thankfully our mash temp was spot on 65C after adding the grains which was nice.

65°C mash temperature - spot on after adding our grains

After doughing in, we always leave the grain bed to settle for 10 minutes before taking our pH reading, so we used this time to make the pH adjustments to our sparge water. Anything under 5.6 is generally considered acceptable, so 5.57 is a pass.

After waiting 10 minutes we took our mash water sample and after chilling in a bowl of ice water we had a pH reading of 5.47. We probably would have preferred a bit closer to 5.3, but as long as we're in that 5.2-5.6 range then we're good.

We then setup our adjustable sparge arm featuring the sergeant sparge head and began recirculating the wort for the 60 minute mash period.

After the 60 minute mash time we raised the temperature from 65°C to 75°C for a 10 minute mash out. We then lifted the grain basket out of the BrewZilla and began sparging using our new integrated sparging setup. Unfortunately we don't have any photos of this during the brew day as this is when things began going a little sideways....

Here's a photo from my testing of the setup so you can hopefully see what we're talking about. We're using our Spike Flow pump to pump our sparge water from the Digiboil (pictured below on the milk crate) into the sparge arm on the BrewZilla instead of manually sparging by pouring into a glass jug, which is then subsequently poured over the of the grain bed for rising the grains of any residual sugars.

Picture from our integrated sparge water pump setup

Although this setup did technically work, there were a couple of key problems. Firstly, we burned through our sparge water super fast - we always do extra sparge water just in case, and we only knew that we'd gone through it all when the pump started to run dry!

The next problem was that the sparge water had gone straight through the grain bed meaning we had massively overshot our pre-boil volume. Using the sergeant sparge head here we suspect was part of the problem as the spray pattern shoots to the outside which likely caused the water to trickle down the edges of the grain bed and basket, rather than through the grain. This means we didn't extract anywhere near as much sugar as we normally would. So we ended up with too much volume and not as much extracted sugar from the grain as we expected from the recipe.

Taking the pre-boil gravity reading was confirmation that things had not worked out with a worryingly-low 1.034 gravity reading - a full 10 points lower than our recipe predicted.

Pre-boil gravity reading was disappointingly low at 1.034

Although bitterly disappointed at this, we desperately wanted to press on and salvage whatever we could from this, so we re-adjusted our recipe by increasing the boil from 30 minutes to 80 minutes. We boiled for the first 20 minutes and then added our first hop addition and treated it like a typical 60 minute boil from there. The increased boil time would help evaporate more of the water, leading to slightly less volume, but a higher original gravity (OG) for fermentation.

We also decided to add 220g of dextrose to help increase the fermentable sugar in the wort as we were still going to be a little low for the style, even with the increased boil time. After making some adjustments to our recipe in Brewfather it predicted we could hit our 1.044 original gravity by doing this. Let's go.

Saaz hops as dictated by the recipe

Measuring our the Saaz hop addition

We measured out and added our 60 minute hop addition with 41g of Saaz hops.

We then measured out our 5g of yeast nutrient and our half whirlfloc tablet which were added to the boil with 10 minutes left.

Yeast nutrient measured out along with half a whirlfloc tablet

We also added our 220g of dextrose with approx 10 minutes left in the boil

Dextrose to the rescue

With 5 minutes left we added our final charge of Saaz hops before attempting to chill down the wort, which brings us to the next issue we faced.

For this brew we attempted to use our new counterflow chiller, and although we tested this beforehand, we for whatever reason were unable to get the BrewZilla pump to pump the wort through the chiller - it just didn't seem to be strong enough.

Troubleshooting this was a bit stressful since our wort was still well over 90°C and was therefore creating more bitterness than we wanted, and we also had to be careful with disconnecting things that we didn't end up getting sprayed with boiling hot wort. In the end we gave up, quickly grabbed our stainless immersion chiller and cooled the wort that way.

Our final gravity reading was a pleasing 1.045 - bang on what our adjusted recipe had predicted which was quite a relief, and will hopefully mean a still decent beer is to come!

We chilled the wort to around 40°C before transferring it to our Apollo Titan fermenter and left it in our fermentation fridge overnight to chill down to pitching temperature (13°C) before adding our two packets of W34/70 yeast.

So, as we previously mentioned, things certainly didn't go smoothly for us, but we still ended up with what will hopefully be a decent wort and finished beer. We've certainly learned a few lessons from this one and were pleased we were able to adapt on the fly to help salvage what we could from this one.

We had fermentation activity within 24 hours of pitching the yeast, and after fermenting at around 13°C we steadily increased the temperature after FG was reached over several days for a diacetyl rest before cold crashing for around 48 hours and pressure transferring to a keg.

Want to see how this one turned out? Check out our Munich Helles Tasting Results & Review post

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