My brew day woes continue

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Crusty
Light Lager
Light Lager
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Joined: Fri Mar 05, 2010 5:05 am
Location: Gulmarrad, NSW, Australia

My brew day woes continue

Post by Crusty »

Hi guys.
I'm wondering if anyone could possible steer me in the right direction in trying to dial in BTP using my Braumeister. I did a simple APA today & aiming for 24.0L @ 20°C into my fermenter. My efficiency was set to 70% & my volume adjustment was set to -4.0L for my trub loss. My actual figure was 3.6L of loss to trub. My grain bill was 5.62kg.
I should of got 29.5L @ 100°C ( 1.039 ) pre boil. My actual was 28L @ 1.042.
I had my boil off set to 3L/hr & a 90min boil so loss to boil should of been 4.5L. I ended up boiling off quite a bit more with only 14.6L to my fermenter + my 3.6L of trub but my gravity was 1.058 temp corrected instead of 1.046 expected. My efficiency was therefore more like 74% to work out my grain bill. My boil off would be something more like 5L/hr at a guess.
I went into the dilution calculator & put in my 14.6L fluid 1 volume
I put in 1.058 fluid gravity 1
I left 1.000 for fluid gravity 2
I put 20L ( expected fermenter volume ) in combined volume
I then get 5.4L in fluid 2 volume
I get 1.042 combined gravity which is short of my expected 1.046 for the recipe.
If I then change my fluid 2 volume to 3.7L, combined volume is then 18.3L @ 1.046 ( recipe expected )
So adding 3.7L to my 14.6L I'll get 1.046 but only 18.3L instead of 20L expected into my fermenter. How would this be worked out in my recipe for my efficiency?
If any of you can possibly help, I would greatly appreciate your knowledge.
Thanks in advance
Brian
The Electric Brewery, 3 Vessel, 30A
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slothrob
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Re: My brew day woes continue

Post by slothrob »

Grain potential will vary between lots and types, but a reasonable average number is 79.2 gravity points per kg. So, you have a potential of 79.2 points/kg x 5.62 kg = 445 total gravity points

Preboil, you had 28L x 1 gallon/3.785 L x 42 points/gallon = 310 points

310.8/445 = 0.698, or 69.8% eff.

However, postboil you had (14.6 L + 3.6 L) ÷ 3.785 L/gal x 58 points/gallon = 279 total points
279/445 = 0.627 or 62.7 % efficency.

So, you have either a gravity or volume measurement error, somewhere.
BTP v2.0.* Windows XP
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