Gravity of unfermentables

I was brewing an Irish Red Ale last week when this question came to my mind. So my recipe contained 20% caramel malt. So that's a lot of unfermentable sugars in the wort. My target OG was 1.054 (Actual turned out to be 1.055) and my target FG was 1.028 (Actual should've been 1.015 according to the software). Now I know most softwares don't take into account the unfermentable sugars. I also calculated that the caramel malt contributed to 11 gravity points. So when calculating the OG/FG, should we add those 11 points to the target OG and get a 1.065 wort or what? How do I account for the unfermentables while calculating both the OG and FG?

Crystal malts yield far more fermentable sugars than we have generally been led to believe.

https://www.homebrewtalk.com/showthread.php?t=208361


This thread involves testing fermentablity of wort made with 100% crystal malts. In the test results it is noted that there was a lot of unconverted starch, suggesting that when mashed with a malt with diastatic power the yield should be significantly better.

Don't underestimate the fermentability of crystal...


H.W.

First of all, you should be measuring your OG and FG – the unfermentable sugars are still sugars for the purposes of gravity readings, and your hydrometer will "see" them.

Second, I don't know what software you're using, but low- and medium-roast crystal has almost as many potential points per pound per gallon as 2-row, which your software should include in the estimated OG. You can test this to be sure – edit the recipe and include a ludicrously high amount of crystal or just zero it out, and see if the OG estimate changes.

Third – sounds like you've got a stuck fermentation. 49% is very low apparent attenuation, even for 20% crystal – and, as Owly said, if you're mashing that crystal rather than just steeping it, a lot of its contribution will be fermentable. Warm that sucker up to 72° or 73°, give it a hearty rouse, you should be able to knock a few more points off.