Beersmith 2 and Yakima Valley Hops 3ml hop extract

[TandemTails]

I have a 3mL shot of hop extract from Yakima Valley Hops: https://www.yakimavalleyhops.com/Hop_Extract_3mL_Hop_Shot_p/extracthopshot3ml.htm

I added all of the info to beersmith and want to make sure it's properly calculating the IBUs. According to the link above, "One-milliliter yields around 10 IBUs in 5 gallons of 1.050 wort when boiled for 60 minutes"

According to my recipe, beersmith is calculating 18 IBUs in a 5.5 gallon batch with OG 1.063 when 3mL are added at 60 minutes. This seems low compared to the quote above.

Here's how I have the extract set up in beersmith:

And here's the recipe profile:

Anyone have experience with this?

 

[Oginme]

A couple of things to take into consideration. You are probably using the Tinseth model for IBU which takes into account the effect of wort gravity on isomerization rate. The chart I have seen from YVH is based upon the Rager model, which in my experience tends to predict low for high boil times.