So, as many of you know, I recently snagged the 65L Brewzilla a couple weeks ago. Well, life and a bit of intimidation kept me from using it - until yesterday... Now, as with every new system there are some learning curves to overcome. What I can say in short is: I kept my cool and overcame all the obstacles in one way or another - that I am proud of.
The longer story is this:
In the end, my conversion did not go as planned - Pre-boil gravity was 1.038 vesus 1.056! Post-boil gravity was 1.049 versus 1.063... What caused this? My guess is the mash temperature. This is what I need help with - is it the right assumption and how should I go about correcting it?
Note: I typically use 4 degrees as an offset for my 35L Robobrew and did so in this brew session with the Brewzilla.
So, here's what I noted during my mash:
1. I mashed in at 158 (4 degrees higher than my intended rest temp) and attempted to keep the mash in this range (I intermittently recirculated with the pump during mash-in to move the wort off the probe at the bottom and help wet the grain at the top).
1a. Once mash-in was complete, my brewzilla was raising temp back up to 158 (from 156) but a temperature probe stuck in the middle of the mash read 139! (Nearly a 20 degree difference!)
1b. What did I do? Nothing - I have seen a roughly 8-10 degree difference in the 35L but only used a 2-4 degree offset with better results than the one time I tried a 10 degree offset.
2. During the mash I recirculated constantly as I do with the 35L version which I had hoped would balance the temperature out in the grain bed (which is what I found typically happened in the 35L).
2a. A temperature reading at the top of the recirculated wort near the output only read 140-141!
2b. What did I do? Not much, I started my mash out temperature raise 10 minutes early.... I assume this may have been a bit of a saving grace?? lol
By the end of the boil I was 13 points shy of my intended OG - So, I added roughly 2LBS of LME I've had on hand for some time... (My only real option shy of honey or maple syrup - I figured the beer would already be thin enough) and I got the OG up to 1.060 but I also boiled for an extra 20 minutes or so. I ended up with 9.75 gallons of wort instead of my intended 11 - so I need to adjust my equipment profile a bit too.
Additional note - I did an initial test of the brewzilla temp probe versus the same one used to double check the mash and both read within 1 degree of each other with just tap water in the brewzilla.
So, would a sub 140 F significantly lower my conversion (my thought is yes...) and should I use a 20 degree offset or start somewhere around 10? What I don't quite understand is how it can read 158 at the bottom and then 141 at the output of the recirculation tube!
Is there something else I might be missing? - I did not test pH but used BF and salt/mineral additions to adjust the intended pH.
Here's the recipe: https://www.brewersfriend.com/homebrew/recipe/view/1147713/shuttz-nut-brown-10g
The longer story is this:
In the end, my conversion did not go as planned - Pre-boil gravity was 1.038 vesus 1.056! Post-boil gravity was 1.049 versus 1.063... What caused this? My guess is the mash temperature. This is what I need help with - is it the right assumption and how should I go about correcting it?
Note: I typically use 4 degrees as an offset for my 35L Robobrew and did so in this brew session with the Brewzilla.
So, here's what I noted during my mash:
1. I mashed in at 158 (4 degrees higher than my intended rest temp) and attempted to keep the mash in this range (I intermittently recirculated with the pump during mash-in to move the wort off the probe at the bottom and help wet the grain at the top).
1a. Once mash-in was complete, my brewzilla was raising temp back up to 158 (from 156) but a temperature probe stuck in the middle of the mash read 139! (Nearly a 20 degree difference!)
1b. What did I do? Nothing - I have seen a roughly 8-10 degree difference in the 35L but only used a 2-4 degree offset with better results than the one time I tried a 10 degree offset.
2. During the mash I recirculated constantly as I do with the 35L version which I had hoped would balance the temperature out in the grain bed (which is what I found typically happened in the 35L).
2a. A temperature reading at the top of the recirculated wort near the output only read 140-141!
2b. What did I do? Not much, I started my mash out temperature raise 10 minutes early.... I assume this may have been a bit of a saving grace?? lol
By the end of the boil I was 13 points shy of my intended OG - So, I added roughly 2LBS of LME I've had on hand for some time... (My only real option shy of honey or maple syrup - I figured the beer would already be thin enough) and I got the OG up to 1.060 but I also boiled for an extra 20 minutes or so. I ended up with 9.75 gallons of wort instead of my intended 11 - so I need to adjust my equipment profile a bit too.
Additional note - I did an initial test of the brewzilla temp probe versus the same one used to double check the mash and both read within 1 degree of each other with just tap water in the brewzilla.
So, would a sub 140 F significantly lower my conversion (my thought is yes...) and should I use a 20 degree offset or start somewhere around 10? What I don't quite understand is how it can read 158 at the bottom and then 141 at the output of the recirculation tube!
Is there something else I might be missing? - I did not test pH but used BF and salt/mineral additions to adjust the intended pH.
Here's the recipe: https://www.brewersfriend.com/homebrew/recipe/view/1147713/shuttz-nut-brown-10g