• Welcome to the new forum! We upgraded our forum software with a host of new boards, capabilities and features. It is also more secure.
    Jump in and join the conversation! You can learn more about the upgrade and new features here.

Calculating Volume & Gravity with trub loss

Wiper

New Forum Member
Joined
Jul 19, 2012
Messages
1
Reaction score
0
Hi BeerSmithers,

Would appreciate some help from old hands at this. Just bought BeerSmith and am impressed by the level of detail in it. But my first two test brews have not hit anywhere near their target gravity – in one case I was hoping for a 1072 OG and got a 1050.

I have searched the forums and think I have found out why but don’t quite understand it and want to run it by you.

I am using quite a big kit (100 litre capacity) and did some relatively small test brews in them – 25 litre batch sizes. With the kit being slightly larger, the boiler dead space is relatively large – around 6 litres. I also lose around 4 litres to hops. So I set the Trub Loss to 10 Litres (Assuming the trub loss is wort left in the boiler). Beersmith then increases the amount I should sparge by 10 litres to make up the difference.

But this is where I am losing gravity – I've been adding more water to make up the loss but not adding more sugar to increase the points.

My question is whether this is a brewhouse efficiency issue or whether I am misusing the software?

Should I

a) Set the trub loss to 0 and add 10 litres to my “batch size” to make it 35, then expect 25 to land in the fermenter?
b) Decrease my brewhouse efficiency way down to around 55% to account for the extra water needed? This will clearly improve as I do larger brews and the 10 Litre of trub loss is not so great relative to the brewlength.

If a), is there anywhere to add in a calculation to account for loss to hop absorption and boiler deadspace that re-calculates the grain needed? Or do I need to just keep this calculation separate?

Many thanks

Michael
 
If you go back to your previous batches and assuming all of the actual numbers were entered you'll see what the Measured Efficiency was. Take that and enter it into your new recipe for your Tot Efficiency. From there you can use the Scale Recipe feature to bring the gravity up to where it should be.
 
If you tell BSmith the constraints of your system:  losses, desired batch size, etc., and your typical efficiency, and then enter a recipe that achieves your beer goals:  OG, SRM, etc., it should get you close than you're getting. 

I'm guessing you are using an efficiency setting higher than you're actually achieving, unless some other setting in the Equipment Profile is incorrect. 
 
Hi BeerSmithers,

Would appreciate some help from old hands at this. Just bought BeerSmith and am impressed by the level of detail in it. But my first two test brews have not hit anywhere near their target gravity – in one case I was hoping for a 1072 OG and got a 1050.

I have searched the forums and think I have found out why but don’t quite understand it and want to run it by you.

I am using quite a big kit (100 litre capacity) and did some relatively small test brews in them – 25 litre batch sizes. With the kit being slightly larger, the boiler dead space is relatively large – around 6 litres. I also lose around 4 litres to hops. So I set the Trub Loss to 10 Litres (Assuming the trub loss is wort left in the boiler). Beersmith then increases the amount I should sparge by 10 litres to make up the difference.

But this is where I am losing gravity – I've been adding more water to make up the loss but not adding more sugar to increase the points.

My question is whether this is a brewhouse efficiency issue or whether I am misusing the software?

Should I

a) Set the trub loss to 0 and add 10 litres to my “batch size” to make it 35, then expect 25 to land in the fermenter?
b) Decrease my brewhouse efficiency way down to around 55% to account for the extra water needed? This will clearly improve as I do larger brews and the 10 Litre of trub loss is not so great relative to the brewlength.

If a), is there anywhere to add in a calculation to account for loss to hop absorption and boiler deadspace that re-calculates the grain needed? Or do I need to just keep this calculation separate?

Many thanks

Michael
I've also noticed that the OG estimate changes when I don't consider the deadspace volume.

I don't know how to explain it in technical way, but I think the deadspace (trub loss) volume should be considered for calc the Original Gravity, because the fermenter receives only a part of the boiled wort.

Does the OG calculation consider the total post-boil volume (fermenter plus trub)?


EDIT: I asked Brad, and he explained to me about the relationship between BH efficiency and OG in BS.

Thanks and cheers.
 
Last edited:
Back
Top