latest brew

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rodneygullick
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Joined: Mon Jun 13, 2011 2:24 pm

latest brew

Post by rodneygullick »

hi guys just made a beer I had a choice of two evils 23 liters or og, I went for the 23 liters , I ran 29 liters into the kettle after 1 hour boil I ended up with aprox 23 liters but my og was down 13 points ,should have been 1071 it was 1058 (question) is there a set of tables out there somewhere to compensate (eg) to increase the malt contents etc
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I_used_to_brew
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Re: latest brew

Post by I_used_to_brew »

It's not that simple, you need to know your system wort losses and your mash efficiency to get anywhere. These should not change if you don't fiddle with your equipment, but mash efficiency can change slightly depending on the malt.

For a 23 litre batch, 6k of malt should give 1.060, so I would have expected your recipe to have used 6k of base malt (it's easiest to disregard any other malts for calculation purposes in many beers). 1.070 would need about 7k of base malt.
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EckersKlein
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Re: latest brew

Post by EckersKlein »

Wort volume and SG points scale proportionally during boiling, so if you boil 10% of your water away, you'll gain 10% SG points (e.g. 1.050 -> 1.055).

If you measure your SG and volume at the beginning of the boil, then you can figure out how much water you need to boil off to hit your target OG. Say you start the boil with 30L at 1.050, and your target OG is 1.060. First, we calculate what % the SG needs to go up by.

Code: Select all

60/50=1.2
. That's a 20% increase, so that means you need to boil off 20% of your water. Boiling off 20% of 30L leaves you with 24L. So in theory, stopping the boil at 24L would give you your target OG for this example. Of course it wouldn't hurt to take additional SG and volume measurements throughout the boil to make sure you're on course.
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rodneygullick
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Re: latest brew

Post by rodneygullick »

the recipe was for 6 gallons which is 27.2 liters I should have put this amount in the kettle and ended up with aprox 21 liters not 29 liters in the kettle and ended up with 23 liters that would have probably put it closer to the target I needed
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I_used_to_brew
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Re: latest brew

Post by I_used_to_brew »

rodneygullick wrote:the recipe was for 6 gallons which is 27.2 liters I should have put this amount in the kettle and ended up with aprox 21 liters not 29 liters in the kettle and ended up with 23 liters that would have probably put it closer to the target I needed
If the recipe is for a 27.2 litre brew length then that's what you are aiming for out of the kettle into the FV.

I'm not sure how you work out recipes but I find it easier to concentrate on what volume I want in the FV and work back from there. I'll always want more in the FV than I want in the cask due to losses to trub/yeast - so factor this in too.

23 litres in FV,
loss to grain due to absorption = 1L per kg = v
Loss to hops = (6L per Kg) = w
Loss to evaporation = x (only you know this for your kettle)
Loss to deadspace in MT = y (only you know this for your MT)
Loss to deadspace in Kettle = z (only you know this for your kettle)

So I work out how much water I need to treat beforehand by adding 23+v+w+x+y+z

Typically that might be 23+6+0.6+3+2+2=36.6Litres

I would mash in with 15Litres (2.5Litres per Kg) and run off whilst sparging with the remaining 21.6Litres. Because everything is worked out beforehand then just put the kettle on and boil as you did previously when you determined your loss to evaporation. End of boil simply run off and Bingo! 23 litres in the FV. No stressing about pre-boil volumes etc.

This is just how I do it, you can choose your own way :)
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rodneygullick
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Re: latest brew

Post by rodneygullick »

thank you Eric and Roger
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