Effect of table sugar vs invert sugar on final gravity

[artichoke]

Hi,

I've been coming through the threads but can't seem to find an answer for a simple question I have.

Suppose I make 2 worts, both with the same grist, but one of them has table sugar to bring up the OG to x and the other uses inverted sugar to bring the OG up to the same OG x. If both worts are subjected to the identical yeast pitch and fermentation process, which can I expect to finish with the lower FG?

I realize that table sugar and inverted sugar are 100% fermentable, but have also read that inverted sugar is easier for the yeast to process and I am wondering if using inverted sugar instead of table sugar may help my too sweet tripel's to dry out a bit better.

Has anyone done any experiments between the two and do you have any data to share?

Thanks.

- Artichoke

 

[jddevinn]

The yeast are going to convert the table sugar to glucose (dextrose) and laevulose (fructose). Inverted sugar is already glucose and laevulose so it will ferment "easier". With healthy yeast, correct pitch rate and properly oxygenated wort will attenuate the same.

Adding sugar isn't going to dry out the beer without you reducing the equivalent malt. It will lower the gravity, add alcohol and thin the mouthfeel but won't remove the "sweet" that is already there. It MAY make the beer "taste" drier.

My suggestions from what I consider best to worst...

- Easiest way to dry out the beer is to use a low mash temperature. (147-150°F - ish). This is where I would focus. I do my Triple at 147°F for 90min then 155°F for 30.

- Amylase can be used preboil to break down some of the complex sugars into fermentable sugars.

- Use a higher attenuating yeast. Assuming that you want a to use your yeast for taste then finish with a high attenuater like Nottingham.

 

[artichoke]

Thanks for the reply.

For 24L into the fermenter, the grist in question was 6.75 kg Weyermann Barke pils, 150g Weyermann acidulated and 200g Gambrinus Honey malt. 5g each of CaSO4 and CaCl2 to the mash, soft Vancouver BC water.

I definitely mashed low, and did a step mash:
-20 mins @ 132F
- 60 mins @ 150F

OG was 1.064, 60 sec pure O2, yeast nutrient, fermented with a large pitch of fresh WLP550 slurry from a low ABV starter beer (probably overpitched actually my notes say I pitched 450 mls of slurry). Note that WLP550 is supposed to be a very high attenuator. I added 3 staggered table sugar feedings starting after high krausen, for a total of 1.25 kg table sugar.

FG after 3 weeks was only 1.016 which was surprising to me, I was hoping for around 1.010-1.012.

I plan on re-brewing this without the honey malt as this didn't help the sweetness factor / FG, but it was a very small % of the grist so that can't be it.

I'm wondering if I would have better success using inverted sugar next time around. Did the yeast give up prematurely because they were working too hard on the more complex table sugar? Or would I have better success reducing the amount of base malt to acheive a lower FG.

- Artichoke

 

[jddevinn]

By adding the sugar you upped the OG from 1.064 to 1.081. At 1.016 you have 80% apparent attenuation compared to the 78-85 range Wyeast gives WLP550. At 1.010 you would have 88% attenuation.

I don't think your yeast gave up. They did all they could do, next time either use less sugar or less base malt.

Calculation for gravity change are below.

 

[artichoke]

Thanks Jason for the detailed reply. Your effective OG is the same as mine, when I plug the numbers into Brewer's friend and account for the additional volume of water added to dissolve the sugar into the fermenting wort.

So in summary, the fermentation went pretty well, attenuation was in the low-average range of WLP550 and the FG is not unexpected, but a tad on the high side. Circling back to my original question, I can't help but wonder if the attenuation would've been slightly better if I'd replaced the table sugar with invert sugar to make the job easier on the yeast before they gave up. There must be a reason the Belgians go through this effort?

- Artichoke.

 

[Denny]

There is no difference in the end results between using table sugar and invert sugar.

 

[jddevinn]

It will speed time, and MAYBE create some different flavors, but the end attenuation should remain the same.

 

[Denny]

It will speed time, and MAYBE create some different flavors, but the end attenuation should remain the same.

In my experience, it will not speed things up and will not affect the flavor due to the inversion.

 

[Mer-man]

That Barke pils sure is taking off!