Help! wild difference in IBU and OG between Brewtarget and Beersmith!

[uofmguy]

So I have a recipe for a rauchbier and I plugged it into both beersmith and brewtarget and came out with two wildly different IBUs. I have the same boil volume / batch volume / efficiency for each so I don't know what went wrong...

The IBUs:
Beersmith 33.2
Brewtarget 41

OG/ABV:
Beersmith: 1.050/5.1%
Brewtarget: 1.044/4.3%

Here's the recipe:
Partial Mash
5 Gallon Batch
2 lbs light DME (24% grain bill)
2 lbs Weyermann's smoked malt (24% gb)
3 lbs Munich (35% gb)
1.5 lbs Vienna (18% gb)

1.5 oz Vanguard pellets 60 min
0.5 Vanguard pellets 30 min
0.5 Vanguard pellets 3 min

WL029 German Ale/Kolsch Yeast (fermented at lower end of fermentation range)

 

[GilaMinumBeer]

Check the ppg/aau for each grain/hop between the softwares and check the equipment metrics

 

[uofmguy]

AAU is the same. And I'm not sure how to find the PPG, but they have the same mash efficiency percentage.

 

[LLBeanJ]

Check the Options in Beersmith to see if IBUs are calculated with Rager or Tinseth formula. I believe Tinseth will show lower IBUs than Rager. Not sure which formula Brewtarget uses.

 

[GilaMinumBeer]

AAU is the same. And I'm not sure how to find the PPG, but they have the same mash efficiency percentage.

I forget how to get there but you would essentially edit the grain you've picked. Somewhere in there it should list the ppg for the grain type. On the hops make sure the efficiency radio button is the same for pellet hops. IIRC, BeerSmith has an option to increase the efficiency for pellet.

 

[GilaMinumBeer]

Check the Options in Beersmith to see if IBUs are calculated with Rager or Tinseth formula. I believe Tinseth will show lower IBUs than Rager. Not sure which formula Brewtarget uses.

This too. Make sure the IBU formula is the same.

 

[uofmguy]

I changed all the hops to leaf and the difference is now just 33-30 IBUs. So must've mostly been the pellet efficiency that was different. Both use Tinseth. A 3 IBU difference is fine by me.

Annddd as for the difference in OG/ABV..... I just saw that I had the amounts of two of the malts entered in wrong in brewtarget.... so... yeah.... now that's good