SRM values in Beersmith2

I'm fairly new at both homebrewing and also beersmith,  but today, I tried in-putting a few clone recipes. 

Beersmith2 calculations seemed to match the specs in the book fairly closely except for the SRM values.  The Beersmith2 estimates predicted a considerably lighter beer than the book suggests.

I suppose the problem could just as easily be with the book as with beersmith, but I wondered if this was a known issue with Beersmith2. 

A recipe that I wanted to try soon is  a "Newcastle Brown"  clone.

In the grain bill, the recipe includes 2 oz of chocolate malt.  I had to increase this to 6 oz in Beersmith2  in order to get Beersmith to show an SRM value similar  to what the book suggested, and to get the colour representation in Beersmith2 to look like a
Newcastle Brown (actually it still looks a bit on the light side with 6 oz chocolate but i was a bit afraid of increasing the amount further, and the SRM numbers did come up about right with 6 oz.)

So what I am wondering - whether to trust the book or trust Beersmith2?

If I do increase the chocolate malt from 2 to 6 oz,  is this primarily going to just darken the beer or will it have any significant impact on the taste?

Any and all advice appreciated - I'd like  to avoid screwing  up a batch!


Thanks ......................  Brian.

(PS - I noticed with several other recipes from the same book that Beersmith2 was consistantly showing a considerably lower SRM when I input the recipe.  IBU's and ABV5 figures matched fairly closely. )

IMO, two ounces of chocolate malt will get you hints of roast, some red hues in color, and will darken it nicely.  Six ounces would be more noticeable, flavor-wise, and give more of the other stuff too. 

You may want to check that the Lovibond of all the grains are identical.  Chocolate malt in particular varies a lot between the different maltsters. 

Thanks for the input - maybe I should stock closer to the book recipe and not worry about the colour - it still falls in teh range of an english brown ale anyway.

I did notice that the book called for British chocolate malt and British black malt in the recipe.  When I picked the grains from the beersmith2 list it didn't refer to the grains as British, so maybe there is a difference between US & British varieties.


Brian