How much alcohol % does 100g of dectros add to 1 litre

TheDuke

Hi all,

I'm sure this has been asked many times but much alcohol % does 100g of dectros add to 1 litre - I'm just looking for the rough ratio.

My research has it a 5% (not that that makes sense in real life - i get that)

Thanks,

The Duke

Paz-CCFC

I got roughly 3.4%

The chemical reaction of sugar to alcohol is: C6H12O6 = 2C2H5OH + 2CO2.

So, one mole of sugar creates two moles of alcohol. One mole of sugar = roughly 342g, so 100g = 0.292 moles. So, it creates 0.584 moles of ethanol. One mole of ethanol is just over 46g, so this reaction creates 26.864g of ethanol. Ethanol has a density of 0.789 g/cm3, so that's 34.048ml. So, that in 1,000ml of solution = roughly 3.405%. That's the theoretical yield, anyway.

But, I think dextrose has 95% fermentability (compared to 99%+ of table sugar). So, that would reduce it to about 3.2%, maybe?

oblivious

Paz-CCFC wrote: »

I got roughly 3.4%

The chemical reaction of sugar to alcohol is: C6H12O6 = 2C2H5OH + 2CO2.

Table sugar is a dimer of Sucrose and fructose =C12H22O11: 342g

Dextrose or D glucose is=C6H12O6: 180g

Paz-CCFC wrote: »

But, I think dextrose has 95% fermentability (compared to 99%+ of table sugar). So, that would reduce it to about 3.2%, maybe?

Both should be 100% fermentable, but the sucrose is going to be needed to be broken down first by the enzyme invertase to release glucose and fructose.

From a brewing prospective sucrose has a potential of 1.046 or 4.6% denser that an equivalent volume of water.

100g/L of sucrose will give a specific gravity of around 1.038 and if this fully ferments out (1.000 FG) then this will give by volume around 5% alcohol (38-0/7.46).

loyatemu

Brewmate reckons 4.99% for 100g of Dextrose in 1L (& exactly the same for Cane Sugar).

oblivious

loyatemu wrote: »

Brewmate reckons 4.99% for 100g of Dextrose in 1L (& exactly the same for Cane Sugar).

"Oh, I forgot to er, carry the one."

TheDuke

Holy sh... where did you guys find your brains... Me mere mortal googled it...

Good to hear the ratio works....