DIY Caramel = mountainous FG?

Fellas, for sh*ts and g1ggles I decided to try something last brewday that I have been wanting to try for sometime now in an attempt to really shove a solid malt backbone into my Best Bitter - and that is the idea of boiling a small subset of wort down to a caramel syrup and then adding back to the main boil.
My mash params were also pretty standard - 1 hr 30 mins at 155f.
I think my quantities for the caramel extraction were pretty standard too - I started with 2 litres/quarts and I'm proud to say I got it down to a thick tar-pit consistency by the end and about half a cup available.
OG once the syrup and wort were reacquainted was 1055 in 23 litres.
Now fermentation was interesting. Started super quick and...finished super quick. No airlock activity after about 3 days. not usual for my conditions
2 weeks later (gasp) FG is 1020... 63% attentuation. ?! Without the caramel syrup Beersmith had me up for a FG of 1012..
Now the complicating factor is that because LHbS was out of my house yeast (wyeast 1968), I had a crack at a cheap dry yeast (Sterling Ale Yeast - some cheap australian manufactured crap). Anyway, point is the spec sheet for this yeast brags about its attentuation capabilities (so I'm going to assume its a high attenuator).
So what the hell happened here - I just cannot believe that half a cup of caramel syrup in 23 litres of wort can add a whopping 8 points of FG? Or is that exacly what it is intended to do..?

Hey, lone-wolf!

I like your experiment & may have to try it out as well.

Did you rehydrate the yeast before pitching? If not, the shock of hitting the alcohol may have killed half of them & left you w/o enough to attenuate fully.

Beyond that, I agree that it's hard to see 1/2 cup of caramelized wort making such a big change. Some of the guys making the 12-12-12 beer are getting to about 1.020 FG with a more than 1/2 cup and they started with OGs north of 1.090.

I'd bet on the yeast/pitching technique, I think.

Did you boil down first runnings or a portion of the sparged wort? You have to think about it in terms of how many points you boiled, not the volume of wort.

I have boiled down first runnings like that before and gotten alot of unfermentability from it. If you boiled first runnings then you boiled about 40 total points. Changing them to 100% unfermentable would raise your FG by the amount you reported. I am not saying that is what happened, but it is possible.

Plus, you have an yeast of unknown performance. Probably a combination of those plus high mash temp gave you this result.

I like to boil down first runnings too, just think about it in terms of points you are boiling next time and brew something you can brew consistently then compare.

lone_wolf said:

(Sterling Ale Yeast - some cheap australian manufactured crap)

Click to expand...

I had similar results with a chocolate stout I brewed a few weeks ago using that yeast. Mashed at 155F. Started at 1.066, "finished" three days later at 1.030 and stayed there for a week until I bumped it up to 72F, and it dropped a few more points after that, but nowhere near where it should be. I'm planning on racking it onto a cake of 1056 when I get a chance in an attempt to get it to take off again.

Needless to say, I won't be using the Sterling yeast again.

Reno said:

Did you boil down first runnings or a portion of the sparged wort? You have to think about it in terms of how many points you boiled, not the volume of wort.

I have boiled down first runnings like that before and gotten alot of unfermentability from it. If you boiled first runnings then you boiled about 40 total points. Changing them to 100% unfermentable would raise your FG by the amount you reported. I am not saying that is what happened, but it is possible.

Plus, you have an yeast of unknown performance. Probably a combination of those plus high mash temp gave you this result.

I like to boil down first runnings too, just think about it in terms of points you are boiling next time and brew something you can brew consistently then compare.

Click to expand...

Ok thats a fair question - but in fact I boiled down 2 litres of wort not the first runnings (and that wort was at 1056). I really do not think a 155f mash temp can be blamed for the FG, Ive mashed at these temps before with plenty of medium crystal malt and hit FGs of 1014 on LOW-attentuating yeasts (ie wyeast 1968).

wmtunate said:

I had similar results with a chocolate stout I brewed a few weeks ago using that yeast. Mashed at 155F. Started at 1.066, "finished" three days later at 1.030 and stayed there for a week until I bumped it up to 72F, and it dropped a few more points after that, but nowhere near where it should be. I'm planning on racking it onto a cake of 1056 when I get a chance in an attempt to get it to take off again.

Needless to say, I won't be using the Sterling yeast again.

Click to expand...

how very interesting. thanks for chipping in sir. So while we are on the subject of this yeast can I ***** a little more..? Not only did the damn thing refuse to attentuate but after 2 weeks was still refusing to flocculate (despite the spec sheets suggesting it was a high flocculator). The final insult(s) were the off-flavors it seems to have produced in the batch - lots of (what my nose detected as) sulphur - and this was after 2 weeks of fermentation at its advertised "ideal" temperature (22 celcius).

Similar issues for you..?

wmtunate said:

I had similar results with a chocolate stout I brewed a few weeks ago using that yeast. Mashed at 155F. Started at 1.066, "finished" three days later at 1.030 and stayed there for a week until I bumped it up to 72F, and it dropped a few more points after that, but nowhere near where it should be. I'm planning on racking it onto a cake of 1056 when I get a chance in an attempt to get it to take off again.

Needless to say, I won't be using the Sterling yeast again.

Click to expand...

Are you worried about oxidation at all?

lone_wolf said:

Ok thats a fair question - but in fact I boiled down 2 litres of wort not the first runnings (and that wort was at 1056). I really do not think a 155f mash temp can be blamed for the FG, Ive mashed at these temps before with plenty of medium crystal malt and hit FGs of 1014 on LOW-attentuating yeasts (ie wyeast 1968).

Click to expand...

That is cool. My input was geared more toward knowing the points you are boiling down and considering that aspect.

Fact is you have 2 vaiables here so there is really no way of knowing. Just giving you something to consider based on my experience.

lone_wolf said:

The final insult(s) were the off-flavors it seems to have produced in the batch - lots of (what my nose detected as) sulphur - and this was after 2 weeks of fermentation at its advertised "ideal" temperature (22 celcius).

Similar issues for you..?

Click to expand...

My stout just tastes way too sweet. But yes, it didn't flocculate like I expected it to, even after 3 weeks in primary.

djfriesen said:

Are you worried about oxidation at all?

Click to expand...

Not any more-so than I would be if I was racking into a secondary, or into a keg for that matter. I didn't say I was going to aerate it. I'll take a chance with slightly oxidizing it vs. having a 3% chocolate stout with a way-too-chewy mouthfeel and sickening sweetness.

wmtunate said:

My stout just tastes way too sweet. But yes, it didn't flocculate like I expected it to, even after 3 weeks in primary.

Click to expand...

ok thanks. then its case closed as far as I'm concerned. Death to Sterling Ale Yeast (bangs imaginary gavel)