Simple sugars and their effect on general fermentability...

[Mr. No-Tip]

Some of you may have seen I did an experiment on simple sugar addition time and its effect on fermentability. One of the most amazing things I found was the final gravity: 1.000.

This is a Belgian Golden Strong with 30% dextrose and 70% pis malt. We know Pils is not 100% fermentable, but both the early and late additions of sugar ended up at 1.000, but a control batch with no sugar finished at 1.010. I see no evidence that the 1.000 batches are infected.

We often talk about adding simple sugars to 'dry out' a beer, but I've never really processed what it meant. I think I am observing the extreme end of it. My conclusion is that the simple sugars have either:

Increased the fermentability of the beer...not sure how.
Or increased the yeasts appetite for /ability to process 'unfermentables'.

I don't think I've come across an observation or explanation for this sort of thing before. Any ideas?

 

[Kodos]

Generally the idea that simple sugars will dry out a beer is explained in the context that the simple sugars are replacing an amount of complex sugars to hit the same original gravity. (ie a 1.060 gravity wort with 20% simple sugar will finish lower than a wort with 100% malt).

In this case, could the extra alcohol be skewing the reading? Since alcohol has a much lower gravity than water, it is possible that by adding sugar (and creating more alcohol and no more dextrines) you are making a lower gravity liquid, but retaining the same amount of unfermentables?

The alcohol factor is how some beers manage to produce readings below 1.000, maybe that's in play here?

What do you reckon the abv of this golden strong is now?

 

[Kodos]

In the words of Kanye, that explanation be all wordy and sh!t.

Try it this way.

If you took any beer, and added pure alcohol, the beer's specific gravity would drop - but you have not removed any residual dextrines. This is (probably) a result of more alcohol rather than a re-energised yeast consuming previously unfermentable sugars.

 

[Mr. No-Tip]

By a simple calculation, it's 9.45%. Even if alcohol did drop the gravity lower, 10pts of gravity in the control batch is a lot to get lost in an alcohol neutralisation...

It certainly tastes sweet. I am assuming 'alcohol sweet'

 

[Black n Tan]

I think it is just the affect of the ethanol on gravity. Ethanol has an SG of 0.785. If 30% of the fermentables were replaced by simple sugar, it would easily drag down the gravity 10 points. What was the SG of the control? Can you explain the make-up of the control compared to the sugar addition batches?

 

[Mr. No-Tip]

1.052 OG of Pils Malt.
20 points of OG from simple sugars.

I think I am starting to get what ya'll are saying. Is my FG accurate now?

 

[Black n Tan]

Your FG and alcohol content will be accurate. Your beer will have an attenuation of 100% or more accurately an 'apparent attenuation' of 100% (OG-FG/OG expressed as a %) because it is skewed by the alcohol. The real attenuation will be somewhat less. You can get an apparent attenuation greater than 100% and FG less than 1.000, however the real attenuation will always be less than 100%. Hope that makes sense.

 

[angus_grant]

::subscribe::

 

[Samuel Adams]

Excellent info !