Kettle an fermentor target changes ibu and pre boil og

[underdogsbrewery]

I want to do 10 liters of beer in the fermentor and I have 3 lt kettle dead space an 6.6 boil off with 79 efficiency ending kettle and 60 brew house
Now if I set fermentor target on the recipe editor i get:
Og 1.076
Batch size fermentor 10lt
Lt pre boil 19,8 ( recipe tools )
Og preboil 1.038 ( it should be 1.050)
Ibu 45.04
Eff. 60

But if I set kettle target I get
Og 1.076
Batch size kettle 13 (I added dead space)
Lt pre boil 19.8
Og pre boil 1.050 (right)
Ibu 31.12
Eff. 79
There's a bug in estimate pre boil and it changes the Ibu? Or I'm wronging something

 

[Yooper]

Boil volume impacts IBUs, but I don't understand this;
"I have 3 lt kettle dead space an 6.6 boil off with 79 efficiency ending kettle and 60 brew house"

Where is the wort going? To "lose" that much efficiency is wild. The batch size should be the finished volume of wort, although I just heard from someone who said they had 2.5 gallons(!) of trub losses after the boil and that really screwed up the projected preboil/post boil OG.

 

[underdogsbrewery]

I apologise and thank you
At the end of brewery I was tired and i went crazy with numbers
I did the batch set on fermentor size but with kettle efficiency so I mistaken everything
However fixing the wort size I had kettle efficiency 79 and brew house 67 a little better respect what I wrote above
Do you think this difference is more acceptable or is to much anyway?
About ibu same thing .. my fault

 

[Yooper]

I apologise and thank you
At the end of brewery I was tired and i went crazy with numbers
I did the batch set on fermentor size but with kettle efficiency so I mistaken everything
However fixing the wort size I had kettle efficiency 79 and brew house 67 a little better respect what I wrote above
Do you think this difference is more acceptable or is to much anyway?
About ibu same thing .. my fault

That's a huge efficiency difference- are you throwing away alot of wort as trub losses? Or having a very very small boil off? Something is wonky with that. Your conversion efficiency is good (I assume that's the 79%) but the brewhouse efficiency shouldn't be so much lower.

 

[underdogsbrewery]

For little batch (10/15 lt, this is the case) I have 79% efficiency kettle but for big batches my efficiency go down to about 70% kettle but in either case I lost about 3 lit in dead space
I think on 10 lit 3 is a big percentage so when I brew in this way I get so big difference
It's my theory, what do you think about?

 

[underdogsbrewery]

Grammatical errors apart

 

[Yooper]

Yes, if you have a 10L batch and are throwing away 3L at the end, that is a huge loss. That is 30% of your wort you're "losing". Why are you losing so much wort? Certainly there isn't 3L of trub. Have you tried the usual techiques, like whirlpooling, straining letting the wort sit and then racking off of the sediment, or pouring it all into the fermenter and letting it compact down.

There really isn't anyway to increase your brewhouse efficiency if you're throwing away 30% of your wort.

 

[GFHomebrew]

2nd that s like loosing 6 or more liters dead space from a 20 liter batch! I've had no issues from just dumping the lot trub hot break and all straight into the fermentor and letting it sort itself out. Sounds like maybe your pickup in your kettle is possitioned too high?

My next brew Im Going to try tieying a fine paint strainer type bag on the end of my transfer hose to catch a bit more crud.

Good luck mate but as yooper stated that's where your efficiency is lagging in your kettle dead space.

 

[underdogsbrewery]

i mate!
Usually I waste 3 liter no matter how much is the batch (also when I do 25 or 50 liter)
There are many reason for this waste when I do around 10 liter
First I work in biab so I can't filter the grain as classic al grain consequently I get more trub squeezing the bag
Second so little batch are sample batch which I ferment in a ss mini bucket without rack to secondary so I prefer bring back less rubbish as possible
And third I boil little batch in the same kettle as bigger batch so ,even if the tap is on the bottom, I let much wort back( I should use a smaller one)
At least those are my idea ..Does it make sense for you?And moreover how much should be usually the difference among kettle and brew house efficiency to sound good?
I opened this thread cause I forgot to put in the right efficiency changing from kettle to fermentor target and I found another trouble ahahahah thanks so much

 

[GFHomebrew]

Yea my dead space is 1 lt loss in 21 liters going into fermenter. Yea i could imagine doing a mini brew in a big pot would result in some major losses.

If my mash efficiency is 90 my bre boil will be around 85 post boil same ish and brewhouse around 80. you get losses at every stage of the process more again if you transfer fermenting brew to secondary then to keg. I lose 2lt in trub from fermenter into my 19lt keg.

There is a great graph on brewersfriend here showing the process and losses from start to finnish. If you get great conversion in the mash but have a poor boil and major losses from your kettle your going to get poor efficiency. Tighten up your losses where possible. Think of ways to reduce your wort losses. Think you want to end up drinking it not pouring it down the drain.

 

[underdogsbrewery]

But I'm a beginner on brewer friends and I can't understand a thing...
changing from brew house eff. To kettle eff. (Taking efficency And volume from brew session) and keeping the pre boil volume the same the recipe editor changes ibu and ebc
It doesn't work for me ... what I'm wronging?

 

[Yooper]

But I'm a beginner on brewer friends and I can't understand a thing...
changing from brew house eff. To kettle eff. (Taking efficency And volume from brew session) and keeping the pre boil volume the same the recipe editor changes ibu and ebc
It doesn't work for me ... what I'm wronging?

I don't quite understand what you're asking. You change your brew house efficiency, using the same volume, starting with the same preboil volume?

The IBU and EBC will change based on the SG of the wort as well as the volume. Is that what you are asking?

 

[underdogsbrewery]

Yes I'm talking about the same recipe.
So The pre boil litres are the same and even the mash volume what changes are the final litres ( ex. 13 lt in the kettle and 10 lt in the fermenter ) and the efficiency (ex. 80%kettle and 62% brew house) , but switching the way to calcolate efficiency and changing those two parameters doesn't the recipe keeps the same ibu and ebc?
(Omitting the question about the huge difference between the two efficiency)