Midnight Brew
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- Joined
- 23/3/09
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Hey Brewers,
Brewed a batch yesterday on my BIAB system which gets me two cubes. This is a bit of a problem I've had in terms of target which Im slowly figuring out.
Hit pre-boil volume spot on, fell short of gravity by 1 point, no big deal. Get to the end of boil and hit post-boil volume spot on and measure gravity and I'm 4 points short. Im putting that down to the accuracy of my refrac but no big deal Im guessing its really 1 point short and the other 3 points are due to temp.
Now recently Ive been falling short of volume by 3-4 litres and I was initally putting it down to loss to grain, different boil rate and then the loss to the kettle. However for this brew these all appear to be spot on as I met my pre and post boil targets for volume. So this batch I fell short by 2L. Less then previously which is good so I went back and had a look at my figures. In this batch I had allowed for 4L of kettle/trub losses and 2L for cooling shrinkage. When I had finished filling my cubes I measure the left overs in the kettle and it was 4L, and I fell 2L short.
I am thinking my actual cooling shrinkage is about 8% (4.32L) instead of 4% (2.08L) which would explain the 2L.
Have I missed or possibly overlooked something or would I be corrent is thinking its a larger cooling shrinage rate?
How much cooling shrinkage do you allow for if you BIAB? (or any method of production)
Brewed a batch yesterday on my BIAB system which gets me two cubes. This is a bit of a problem I've had in terms of target which Im slowly figuring out.
Hit pre-boil volume spot on, fell short of gravity by 1 point, no big deal. Get to the end of boil and hit post-boil volume spot on and measure gravity and I'm 4 points short. Im putting that down to the accuracy of my refrac but no big deal Im guessing its really 1 point short and the other 3 points are due to temp.
Now recently Ive been falling short of volume by 3-4 litres and I was initally putting it down to loss to grain, different boil rate and then the loss to the kettle. However for this brew these all appear to be spot on as I met my pre and post boil targets for volume. So this batch I fell short by 2L. Less then previously which is good so I went back and had a look at my figures. In this batch I had allowed for 4L of kettle/trub losses and 2L for cooling shrinkage. When I had finished filling my cubes I measure the left overs in the kettle and it was 4L, and I fell 2L short.
I am thinking my actual cooling shrinkage is about 8% (4.32L) instead of 4% (2.08L) which would explain the 2L.
Have I missed or possibly overlooked something or would I be corrent is thinking its a larger cooling shrinage rate?
How much cooling shrinkage do you allow for if you BIAB? (or any method of production)