Thanks to forum member Boston, I picked up a 6-pack of 2009 SNCA today! Not being able to withstand my anticipation, I cracked one open to compare with my clone just now. Tasting the two side-by-side, I realize the clone still needs some work. Here's what I've found.
The SNCA is half a year old now, so it's lost a bit of it's hop aroma. But I still think my clone has a bit too much Centennial in the nose. Comparing the two, SNCA smells mostly of sweet malt, while my clone is all hops. I'm going to cut down on the Centennial dry hop amount for my next attempt. The appearance of my clone is slightly darker than the real thing. Probably a difference of 1-2 SRM. Now, that could be due to the fact that I didn't allow the yeast enough time to settle down in the SNCA after I drove it home, but I think the clone is a touch darker. I'll aim for 1 SRM lighter on my next attempt. As for taste, SNCA has the clone beat hands down. I thought the clone was really good until I tasted them side-by-side. The SNCA just tastes more real. Where my clone is a bit soft and indistinct, the SNCA grabs you by the balls and really lets you know it's there. The malt and caramel flavors are very similar, but the SNCA just tastes more SUBSTANTIAL. There is also this bit of tart bitterness right as the SNCA hit the palate that the clone doesn't have. Sweetness is also a bit enhanced in the SNCA. Head retention is better on the clone. Mouthfeel is more full on SNCA.
This was only a quick and dirty tasting to get quick impressions. I'll do a more in depth comparison later in order to hone in on a clone recipe. But right now, here are the changes I'm considering for the next clone.
1. 9:1 sulfate to chloride ratio. I think this is causing one of the biggest differences in flavor. Whereas my beer tastes a bit soft, I think the SNCA has the sharp bitterness it does due to a higher sulfate ratio.
2. Reduce SRM slightly. This isn't a huge deal to me at all. I could really care less if they look the same side-by-side if they taste the same.
3. Reduce centennial dry hop.
4. I'm a bit unsure as to where the tartness comes from in the initial flavor of the SNCA. The sulfate:chloride ratio may have a bit to do with this, but I'm thinking it's partially due to hops as well. Maybe I'll increase the Chinook flavor hop addition slighty and move it back towards the end of the boil a little.
5. Eliminate carapils from the recipe. It isn't used by SN and it causing the clone to have much better foam and retention.
So those are my initial impressions. I hope to have a better comparison sometime in the future. For now, here are some comparison pictures:
SNCA is on the right, my clone on the left
Notice that the clone is slightly darker/richer in color
And here is the head comparison, it's no contest
EDIT: Bitterness needs a boost too. I don't think it's just the chloride:sulfate ratio. I'll add another 10-15 IBU for the next attempt, probably getting a lot of it from the flavor addition of chinook.