Whats your typical FG?

Last week I started fermented an american ipa with s-05. It had an og of 1.071 and had 9 pounds of sorghum syrup and half a pound of sugar in the recipe. I'm debating feed the yeast another half pound of sugar this week to be sure it doesn't finish too high and sweet.

Any thoughts on what I should expect?

Adding sugar won't lower your FG unless you used it to replace some of the base malt, otherwise it just adds a little more alcohol and the gravity stays the same. Typical FG's will depend on the yeast used, the recipe and the OG for that particular brew.

Sorry for the confusion, I meant as a way to "thin" the beer similar to what is commonly done with a belgian. If sorghum based beers commonly finish high, I think a beer that had 9lb of syrup to start with and is highly hopped might benefit from a little sugar to make the finished product a little less cloying.

I've found that my sorghum beers tend to finish much lower than expected. 1.007 FG or so unless I add in some maltodextrin.

BW - Because alcohol has a lower specific gravity than water, adding sugar or any 100% fermentable will decrease the FG. I've got a Pale conditioning that is 30% dextrose and went from 1.051 to 1.008. The manufacturer rated the syrup at 70% fermentables, 84% apparent attenuation is right on target. I added 8 oz of MD post-ferment to give it more body.

Thanks for the feedback guys, sounds like I don't need to worry about a high FG, perhaps the opposite.

So it looks like the beer ended at 1.018 with s-05 and the maltodextrin in the mix. Thats 75% apparent attenuation. I thought it might go down a little lower but that seemed to be all the yeast had in them even after I moved the fermenter to a 70 degree room for a week.

I'm guessing this is going to be a little sweet for a two hearted ale clone and think next time I might wind up trying to replace some sorghum with some sugar, maybe even feeding it a few days into the ferment.

Looks like I might have gotten a little cocky with my old brewing ways. A few days after dry hopping I noticed my beer seemed to blooping the airlock more than usual. I busted out the hydrometer and sure enough it went from 1.018 to 1.014 even after sitting in the primary for a couple weeks with a yeast strain that has a reputation for being a very quick fermenter. I'm going to try to warm the beer up to 70 and see if its really done yet. Guess I shouldn't have been too quick to assume outcomes like all my old barley batches.

The one I bottled today hit 1.012 with maltodextrin added...not sure how to work backwards from that (I used 8 oz)

A little late on the reply here. I was wondering about the FG myself. When I used Safeale 05, the FG always comes out higher - 1.016-23. On the other hand, my AG's FG is always lower- 1.010- 1.012 using WLP 013, 051 & Wyeast 1028 & 1084. Online software says it should finish higher, but it doesn't.

My two sorghum brews so far have finished up at 1012. Took 10 days at ~23C (73F) or so for s-04 to get there, and 3 weeks with s-23 at 12C (54F).