Non Fermentable Sugars

[Rock Zigger]

Can non fermentable sugars such as xylose skew OG readings giving you a very poor FG and assocaited ABV?

Been fermenting a bacth based on an Old Peculiar clone recipe adding plenty of black treacle. We doubled the boil ingreadients and split it out to two 20l buckets and topped it up to an OG of 1.040. Fermented for two weeks and got down to an FG of 1.020. We have now taken it off the original yeast to avoid any odd flavours developing.

Plan to add a brown sugar syrup and repitch the yeast to get it going again as we have discounted room temp problems.

Does this sound like a plan, anybody had simillar problems with Black Treacle batches, anybody got any thoughts on non fermentable sugars and gravity readings??

 

[prolix]

you would expect an OP to finish higher than normal, my last one finished at 1017 but started up at 1064.

1020 from 1040 seem very high FG how much treacle did you use?

20L @ 1064
5000g malt pale /crystal 90/10
100g black treacle
250g soft muscadova sugar
saf04

 

[Rock Zigger]

Put in 225g of Black treacle for each 20l batch, do you think this could be the cause of the problem? Have I over done it on the non fermentable sugars?

The beer its self tastes very good having drunk the FG sample. So the taste is working for me and should get a little better with a bit of age on its side, it just has a very disappointing ABV.

 

[Screwy]

The Sucrose from the Treacle should have assisted the yeast in it's attenuation this yeast can achieve 75% attenuation in good fermentable wort 1.040 down to 1.020 is only 50% attenuation, something is wrong. What was your recipe?

Screwy

 

[prolix]

yeah there is no way the black treacle is resonsible for the lack of attenuation.

not even high mash temps would cause that many unfermentables.

did you take the OG reading at 20c or if not did you factor in the temperature effect?

what reciepe did you use?

did you aerate the wort well before fermentation?

I feel like Nancy Drew with a mystery to solve

 

[woollie]

:lol:

 

[Rock Zigger]

Thanks for your thoughts. The recipe was as follows:

30minute steep:
500g roast barley
500g crystal malt

75 minute boil
4kg dry dark malt extract
120g fuggles
450g black treacle

Boil volume was 20litres with a boil gravity of 1.070 taken at 20 degrees C, final volume was made up to 40l (2 x 20l batches) both at a final gravity of 1.040 taken at 20 degrees C.

We have now repitched with the addition of 1kg soft brown sugar syrup per batch (which lifter the gravity from 1.020 to 1.036), with an aim to get some sort of ABV going and given that it is a dark full bodied brew the brown sugar should not upset the taste to much.