Does this Ibu sound right

[beersnob]

Hi all
A few days ago I brewed a beer from a recipe from the Craft Brew book by Euan Ferguson. The beer in question was Manchester bitter Marble brewery. OG 1040 with the following hop additions : Herkules 16.1%AA 70 mins (3 grams!) goldings 3.4%AA (20 grams ) 15 mins & 25 grams of Waimea 18%AA & 25 grams motueka 8% AA steeped for 20 mins at flame out. What concerns me is the IBU which I calculate to be about 13. This does not sound right. I have a small window this week to brew again , so I am wondering to ditch the original batch & brew again with a IBU somewhere in the 30s. Thoughts appreciated.

 

[Sadfield]

Hi all
A few days ago I brewed a beer from a recipe from the Craft Brew book by Euan Ferguson. The beer in question was Manchester bitter Marble brewery. OG 1040 with the following hop additions : Herkules 16.1%AA 70 mins (3 grams!) goldings 3.4%AA (20 grams ) 15 mins & 25 grams of Waimea 18%AA & 25 grams motueka 8% AA steeped for 20 mins at flame out. What concerns me is the IBU which I calculate to be about 13. This does not sound right. I have a small window this week to brew again , so I am wondering to ditch the original batch & brew again with a IBU somewhere in the 30s. Thoughts appreciated.

My calculations using Beersmith give 40 IBUs. I suspect your method is giving 0 IBUs for the Motueka and Waimea additions at 0 minutes, and not accounting for the isomerisation during the 20 minute steep. As long as you did the steep you should be fine. Great beer that.

It's always worth tasting wort at different stages of the brew, getting used to how things should taste is an easy way to put the mind at rest or flag up potential problems.

 

[ACBEV]

With my volumes your hop additions works out at 13.75 IBU, with BF recipe thingy. Thing is BF thingy doesn't add IBUs after 0 mins, so I reckon its much higher than 13 with your method.

Edit: What Sadfield wrote lol

 

[beersnob]

Thanks it makes sense now. Just adding just 3 grams at start seemed strange.

 

[Clint]

Try the calculator on the forum and put your 0 minute hops in as aroma or whirlpool setting the temp option for around 80 to see potential ibu value.

 

[Sadfield]

Thanks it makes sense now. Just adding just 3 grams at start seemed strange.

It does, until you start to think about repeating the recipe commercially, and see the recipe is worked backwards, where the bittering addition becomes a floating value. For example, if next seasons Waimea hops come in at 17%AA instead of 18%AA, the brewer will still use 25g at 0 minutes in order to keep consistency in the flavour and aroma, and compensate by increasing the bittering addition to keep the overall IBUs at the same value.

EDIT: Regardless of repeat-ability, this is a good tip for recipe creation. Work out the flavour and aroma additions first, they are the most important, then adjust the bittering addition to the right level.

Also as this is a commercial recipe, the 3g addition would be a few Kgs in the brewery and look less unusual.

 

[Clint]

That’s a great post !