Doe's Dextrose Or Plain Sugar Increase The Attenuation Of The Whol

[Oatlands Brewer]

Having just found out that ive lost the computer file containing my recipe for my Double IPA and having to re-write it :angry: , and recent discussions on other threads got me thinking.

does using dex or white sugar, which is more fermentable, affect the attenuation of the entire ingredients in the brew ie extract and grains. Or does it just ad ABV.

If it dosnt what is the danger of having a Malt heavy (sweeter) taste

 

[Pete2501]

Dex is D-Glucose and is a monosaccharide.

I'm assuming you're talking about table sugar which is Sucrose and is a disaccharide. It's made up of a d-glucose and fructose monosaccharide linked with a α(1→2) bond.


http://www.braukaiser.com/wiki/index.php/U...ing_Attenuation

 

[manticle]

I think I know what you mean and have been wondering a similar thing.

eg - If I add 5% sucrose/dextrose to a grain bill will it actually raise my attenuation from 70% to 76% or will it just give me the perception of a drier beer that has the same final gravity?

Certainly the perceived dryness will make a difference. I make belgians with maybe 6-7 kg of malt to get to 1060-1070, mash long and high then add candi sugar incrementally to dry out. Final gravity is around 1012 - not sure which bit is due to long mash and which is due to sugar. 1060-1070 is before the sugar addition. Presuming no matter what the gravity, that the yeast (if healthy) will eat the sugar and whatever unfermentables were in the wort will remain unfermentable give or take a sugar molecule or two.

 

[Oatlands Brewer]

Ahhhh...my brain hurt a little bit after i read that .... :huh:

When i made up the original recipe I included 1kg of Dex to bring up the ABV to 8.6%, and was just wondering if it affects the fermentability of the other extracts and grains.

 

[Pennywise]

I think I know what you mean and have been wondering a similar thing.

eg - If I add 5% sucrose/dextrose to a grain bill will it actually raise my attenuation from 70% to 76% or will it just give me the perception of a drier beer that has the same final gravity?

My understanding/assumption whatever, is that it will do a bit of both - raise the abv but slightly increase the attenuation. I don't know that for sure though and there may be other factors at work.

I spent a good 15 mins writing a long winded post pretty much saying the same thing, so I'll just have to say the dreded +1

 

[Pete2501]

Thirstyboy had a question like this a while back with a bunch of good info I think. I think....


I'll have a look for the thread I'm thinking of and see if it was related.

 

[Oatlands Brewer]

Bang on there Manticle.

There was some discussion of "ensymes" on another thread which sounded like a additive to up the attenuation, but ive never used or seen these.

I know im not making much sense, but im really just worried that with two cans of goo, 2kg of LDME and 1.3kg of grain plus the dex im gonna end up with liquid alco toffee

 

[Pete2501]

This is the thread I'm thinking of.


Mashing High And Adding Dex

 

[Oatlands Brewer]

Thanks Pete, that made my brain hurt some more......but a very interesting thread.

I think that was more about what fermentables are produced at what temps and how they affect the brew...i guess my question is if adding simple sugars have an effect on the other fermentables at (im guessing) an enzyme level.

Man i am way out of my depth here.....

 

[Pete2501]

I spent a week on wikipedia and that other site I linked and it fits in eventually. Keep reading dude. :icon_cheers:

 

[Oatlands Brewer]

Bingo.

So basicly...No

During the boil the enzymes denature the wort and basicly fixes ALL the "gross" (for want of a better term) fermentable sugars which are then fermented along with the other parts of the wort like protein etc.

Thanks Pete

 

[Pete2501]

Dextrose is a monosaccharide and doesn't need any enzymes to break it down (mono) so the yeast will eat it up just fine.

 

[Screwtop]

This is how I see it and how I calculate FG if using sugar or Dex. Produces predictable results for me.

Example 1:

23L
4.4Kg Malt (ppg 1.036)
OG: 1.044
Yeast AA%: 75%
Predicted FG: 1.011
ABV: 4.3

Adding 400G of Dex (ppg 1.046) to the above.
OG: 1.056
Dextrose is fully fermentable ∴ FG should remain the same FG: 1.011
ABV: 5.2
∴ AA% overall is now 77% but this is made up of a attenuation of complex fermentables at 75% and simple fermentables at 100%

So above adding sugar/dex adds gravity, increases attenuation and ABV

However if we start by designing a wort with an OG of 1.044 and want to include Dextrose. Above the Dex is near to 8% of the grist bill so if we aim for 8% Dex in grainbill for wort with an OG of 1.044

Example 2:

23L
3.5Kg Malt (ppg 1.036)
OG: 1.038
Yeast AA%: 75%
Predicted FG: 1.009
ABV: 3.8

350g Dex added to the fermentables to reach OG of 1.044
Dextrose is fully fermentable ∴ FG should remain the same FG: 1.009
ABV: 4.56
∴ AA% overall is now 78% but this is made up of a attenuation of complex fermentables at 75% and simple fermentables at 100%


So in comparison to the original 1.044 wort using only Malt
Apparent Attenuation has increased from 75% to 78%
∴ ABV has increased from 4.3 to 4.56

Mouthfeel or perception of dryness increases simply due to the fact than there are less complex fermentables containing dextrins in wort made using sugar/dex adjuncts, and naturally the percentage of these depends upon mash temp. So regardless of mash saccharification temp fermentation will finish lower and the beer have less body than a malt only wort if sugar/dex is included in the fermentables for a given OG.

Screwy

 

[MHB]

Screwy that's pretty much how I would look at it; this is a worthwhile read Home Brew Wiki - Attenuation
MHB

 

[Oatlands Brewer]

Thanks Screwy.

This quote from Braukaiser is what confused me i think.

"During the boil only minor changes happen to the wort composition. The denaturization of the enzymes finally fixes the ratio between fermentable and unfermentable extract. The coagulation of proteins changes the amount and composition of proteins in the wort. Hops will add additional compounds. But these are of little interest for the discussion of attenuation".

Anyway, im going away to do a LOT more reading.

We will see if my double turns out ok,

 

[Screwtop]

Screwy that's pretty much how I would look at it; this is a worthwhile read Home Brew Wiki - Attenuation
MHB

Thanks Mark, I already have a copy of this saved in my brewing docs. Good info

Cheers,

Screwy

 

[Nick JD]

If an extra 0.7% of your beer has a 0.789 SG, how does your FG remain the same?

 

[Thirsty Boy]

If it makes you feel better, mentally replace the letters FG with the words Residual Extract... and your issue goes away. FG serves as a nice substitution for the purposes of this explanation... and one which doesn't require a page worth of explanation in its own right.

Regardless - it practise it works pretty much exactly as Screwy has explained.... good enough??