odd results when scaling recipe slightly

Hello,
1st time poster, about a 4 month BS2 user.

I'm trying to brew a pale ale recipe from BYO magazine and I get some odd results when I scale it to my equipment.
BYO mag lists base efficiency as 65% and 5 gallons in the fermenter.
I scaled the recipe in beersmith for 75% efficiency and 5.5 gallons in the fermenter.
The original recipe calls for:
11lbs 4 oz pale 2 row malt
8oz Caravienne malt
6 oz Honey malt
The scaled recipe comes back as:
10lbs 4oz Pale 2 row malt
12.1oz Caravienne malt
9.1oz Honey malt

I understand the 2 row quantity dropping because of higher efficiency, but I don't get why the specialty malt quantities increased?

I went back and changed the grain percentages in the modified recipe to match the original recipe grain percentages
and the malt quantities dropped below the original quantities.
10lbs 11.8oz pale malt
7.6oz Caravienne
5.7oz Honey malt

Any ideas? The software's version doesn't make sense to me. My corrected by percentage version makes more sense to me with the efficiency increase more than off-setting the slightly increased volume. But I could be wrong. Math is not my game.

singybrue said:

I understand the 2 row quantity dropping because of higher efficiency, but I don't get why the specialty malt quantities increased?
...
My corrected by percentage version makes more sense to me with the efficiency increase more than off-setting the slightly increased volume. But I could be wrong. Math is not my game.

Click to expand...

That's a perfectly understandable confusion. At any level, recipes don't always scale linearly, but your approach of using percentages is certainly valid for this recipe.

BeerSmith gives you a lots of options when scaling a recipe. Among these is "match original gravity, color and bitterness."  I believe in your first example, this box was probably checked.

An increase in efficiency means more gravity coming from your base malt. Along with grain weight, comes color. Less weight = lighter color. BeerSmith offset the base malt color loss by increasing the specialty malts to maintain the 6.5 SRM color of the original recipe.

With that same box unchecked, BeerSmith maintains percentages, but that can cause a loss of color, gravity and/or bitterness, depending on how much scaling and variations between equipment profiles exist.  In your case, going from 5 gallons to 5 gallons, the color change is 0.5 SRM with matching percentages. Probably not something you'd notice, even if the two recipes were side by side.

Aha! You're right! I didn't notice the difference in color with the various iterations.
Thank you for your insight!