Fermenter/Kettle and Efficiency

[Brewer #64014]

Hello

This has probably been gone over many times previously, apologies if so and please just point me in the direction of the relevant thread.

I can't get my head around the Fermenter/Kettle target thing. I've been using BF for ages but for some reason only had an issue with this recently.

Taking the brew I did today -

if I select 'Fermenter' with size = 19 litre and efficiency = 59% I get OG = 1.057.
if I select 'Kettle' with size = 16 litre and eff = 70% I get OG = 1.057.

All well and good, I get that the efficiency will be higher without the losses. What I don't get is why the IBU and SRM figures are different, and why I have different figures for the total water in kettle? Which one should I use?

I'd be grateful for any helpful advice.

Cheers

Phil

 

[Ozarks Mountain Brewery]

there are a couple always to look at this but in general if you pour everything from the boil kettle into the fermenter, you choose fermenter, if you leave trub in the boil kettle and subtract it in the profile you choose kettle, now your starting and ending water will need to be changed and your defaults will need to be set up to do either, you can’t just click them both with the same settings your readings will be off

 

[deeJay]

there are a couple always to look at this but in general if you pour everything from the boil kettle into the fermenter, you choose fermenter, if you leave trub in the boil kettle and subtract it in the profile you choose kettle, now your starting and ending water will need to be changed and your defaults will need to be set up to do either, you can’t just click them both with the same settings your readings will be off

Hi there,
I have been using BF for 4 or so years and always used fermentor thinking that it meant how much wort made it into fermentor less trub.
but you are saying that it is all the contents of the kettle into the fermentor?
I drain into fermentor and leave trub behind so should I be using the ending Kettle volume ?
cheers.

 

[Ozarks Mountain Brewery]

yes that's correct

 

[deeJay]

yes that's correct

Ok thanks for that, I will use it from now on.
One more thing, I have subtracted trub loss in equipment profile, when you mention starting and ending water is this in the waterprofile set up ?
cheers.

 

[Ozarks Mountain Brewery]

yes, default batch size and default boil size, those are whats calculated

 

[KC]

I have been using BF for 4 or so years and always used fermentor thinking that it meant how much wort made it into fermentor less trub.
but you are saying that it is all the contents of the kettle into the fermentor?

yes that's correct

That's not universally correct. Kettle/fermenter calculations will be the same in that case but they are intended to be different numbers. General recommendation is to use target:kettle for most recipes as OMB points out, for several reasons.

You can use target:fermentor in the recipe editor in certain cases, but you can't switch back and forth on the same equipment profile. It is suited more for brewers that have frequent brews of the same beer on one process, where transfer losses are important. At a homebrew scale, it should only be used for that one recipe with the same equipment and profile every brew day. It's pretty useless for copying or sharing. You can't carry, for example, an 85% efficiency estimate from a weissbeir to an IPA recipe (hops absorption will be different), or from a 7 gallon kettle to a 10 gallon (dead space loss and boiloff rates will be different).

 

[PutnamBrew]

This information is going to be super helpful. I've been putting it to fermenter because I'm aiming for a particular amount in the fermenter and there are times I leave trub behind and I would get annoyed when I hit my volumes but the efficiency went down because of the loss between kettle and fermenter. I'll change it to kettle and see how things go now.

Edit: Holy cow! Besides clicking the drop down box and selecting Kettle or fermenter, I've never explored the differences in water requirements. I selected fermenter with a batch size of 5.5 gallons so if needed, I could leave a half gallon in the fermenter and put a full 5 gallons into the keg. Now I'm seeing what I need to adjust.

Edit II: I did a mock brew session. Why is it that if I hit the volumes and gravity, it's showing 4% lower in efficiency. ELI5 please!

 

[KC]

Why is it that if I hit the volumes and gravity, it's showing 4% lower in efficiency

I'd have to see some details of the brew session. You're seeing ending kettle 4% lower than target:kettle predicted?

 

[PutnamBrew]

I'd have to see some details of the brew session. You're seeing ending kettle 4% lower than target:kettle predicted?

Sorry, I should have clarified.

The kettle efficiency is correct, but the brewhouse went from 72% to 68%.

 

[KC]

I would imagine it's related to hops absorption and the trub contribution to the kettle deadspace, which is not calculated in end kettle. It could be handled differently as a target:fermenter prediction than final calculation. The recipe doesn't have sugar or extract, does it?

 

[deeJay]

That's not universally correct. Kettle/fermenter calculations will be the same in that case but they are intended to be different numbers. General recommendation is to use target:kettle for most recipes as OMB points out, for several reasons.

You can use target:fermentor in the recipe editor in certain cases, but you can't switch back and forth on the same equipment profile. It is suited more for brewers that have frequent brews of the same beer on one process, where transfer losses are important. At a homebrew scale, it should only be used for that one recipe with the same equipment and profile every brew day. It's pretty useless for copying or sharing. You can't carry, for example, an 85% efficiency estimate from a weissbeir to an IPA recipe (hops absorption will be different), or from a 7 gallon kettle to a 10 gallon (dead space loss and boiloff rates will be different).

Hi KC, I understand what you say regarding the kettle/fermentor amounts will be the same but as I leave trub behind in the kett

That's not universally correct. Kettle/fermenter calculations will be the same in that case but they are intended to be different numbers. General recommendation is to use target:kettle for most recipes as OMB points out, for several reasons.

You can use target:fermentor in the recipe editor in certain cases, but you can't switch back and forth on the same equipment profile. It is suited more for brewers that have frequent brews of the same beer on one process, where transfer losses are important. At a homebrew scale, it should only be used for that one recipe with the same equipment and profile every brew day. It's pretty useless for copying or sharing. You can't carry, for example, an 85% efficiency estimate from a weissbeir to an IPA recipe (hops absorption will be different), or from a 7 gallon kettle to a 10 gallon (dead space loss and boiloff rates will be different).

Hi KC, just trying to learn more about the equipment profile. If I was to choose target: fermentor and pour all contents from kettle into fermentor, would I then just change equipment profile - kettle dead space to 0 ?
cheers.

 

[KC]

Kettle dead space, misc losses, and hops absorption should all be 0 if you pour everything in. If you remove a hops bag, absorption should have a number - and bag absorption can go in misc. if its measurable.

You should also have accurate numbers for grain absorption, boiloff rates, and cooling shrinkage. That applies to all cases.

 

[deeJay]

Kettle dead space, misc losses, and hops absorption should all be 0 if you pour everything in. If you remove a hops bag, absorption should have a number - and bag absorption can go in misc. if its measurable.

You should also have accurate numbers for grain absorption, boiloff rates, and cooling shrinkage. That applies to all cases.

So my understanding is that batch size ending kettle amout is the same amount as fermentor with the difference being in the equipment profile ?
cheers.

 

[KC]

They will only be the same if you pour everything in and have the profile set correctly. Otherwise target:fermenter is end kettle minus the various losses of wort typically left behind or absorbed.

 

[swipka89]

Thats really cool