Calculating Ibu When Reducing Wort

[bradsbrew]

Anyone got a calc for working out IBU when reducing left over wort?

Had a bit of a stuff up on yesterdays second brew after a few too many :chug: . Long story short is I was expecting 23L of 1058 wort with an IBU of 67 ended up with 29L of 1046 and an IBU of maybe 58. Mashed at 66

Basically what I want to do is boil down the extra 6L of wort to around 2L and add it with 500g of dry malt extract to the fermenter on day 2 of ferment. Will boiling off the 4L give over the top bitterness.

Cheers

 

[Nick JD]

If you open a new recipe with Brewmate and adjust the hop boil times much past 60 minutes while watching the IBUs, it really doesn't get much more bitter.

I'd guess once you have boiled for 60 minutes you've isomerised all you're gonna isomerise.

Also why the "nochill" button doesn't change the IBUs much if it's only got a 60 minute addition. If it's only got a 10 minute addition, click on "nochill" and the IBUs go through the roof.

 

[bradsbrew]

If you open a new recipe with Brewmate and adjust the hop boil times much past 60 minutes while watching the IBUs, it really doesn't get much more bitter.

I'd guess once you have boiled for 60 minutes you've isomerised all you're gonna isomerise.

Also why the "nochill" button doesn't change the IBUs much if it's only got a 60 minute addition. If it's only got a 10 minute addition, click on "nochill" and the IBUs go through the roof.

Yeah but my only hop editions were

30g columbus at 20 min

40g cascade at 10 min

60g cascade at 0 min

no chill

Cheers

 

[Nick JD]

Yeah but my only hop editions were

30g columbus at 20 min

40g cascade at 10 min

60g cascade at 0 min

no chill

Cheers

Okay. Calculation nightmare! I'm never sure that one algorithm for no chilling can even be implemented as "cooling" depends on a lot of factors.

Good luck.

 

[bradsbrew]

Yep just boiling it down now on the side burner(lamb roast cracking under the hood), just about to throw in 250g of sugar and 500g of DME then 40g of columbus which was going to be the dry hop then crash chill it, put it in the fridge and add it to the rest of the fermenting brew tommorrow.