Idiots guide to sugar, dextrose, spray malt etc?

[alice-edmund]

I've had a scour through the forums - however I've been unable to find a clear, accurate and thorough guide to the differences between the various energy sources. I've been using white sugar (mostly) - plus some molasses. However, getting a clear guide to the names and reasons for dextrose, maltodextrin, sucrose etc - and how they vary would be wonderful. Can anyone point me towards a thread please? And help me improve my beers - I've drunk them all - but improvement is good.

 

[chthon]

• Glucose (dextrose): one of the three most simple sugars. This is completely fermented by the yeast. Sold under the name "brewing sugar"
• Fructose: another of the three most simple sugars. This is completely fermented by the yeast.
• Sucrose: a more complex sugar consisting of glucose and fructose in a chemical bond. Yeast is also able to completely ferment sucrose
• Invert syrup: dissolving sucrose in water, adding a bit of acid (citric, cream of tartar) and raising the temperature to about 114° C for a time creates invert syrup, where the sucrose of the previous item is chemically decomposed into glucose and fructose. Honey and golden syrup are a mix of invert syrup and sucrose.
• Maltotriose: (you might encounter this sometimes in literature), a still more complex sugar which can be fermented by yeast
• Dextrins: dextrins are still more complex compounds of sugars. These can not be fermented by the yeast, but will influence gravity of the wort. These can be decomposed in the mash by the alpha- and beta-amylases which also turn the starches into sugar
• Starch: Still more complex compound, consisting of a whole lot of glucose molecules bound together in more complex molecules. Flours consist mostly of starches. Beer yeast can not ferment starches, but bread yeast can. Starches are also broken down in the mash into dextrins and more simple sugars

Molasses is a byproduct of sugar refining. The best molasses is from cane sugar, this will be the only one actually sold as human food. Molasses from beets is fodder.

Caramel is obtained by heating sugar to around 160° C. There are four kinds, in E terminology, E150a to E150d. E150a and E150b are not stable in color in beer, E150c is, and there are doubts about the E150d's usage in food.

All kinds of crystallised sugar are variations of sucrose. The tints are caused by impurities, which affect the flavor of the final mix. Darker sugars are obtained by colouring them with varying degrees of caramel and molasses.

Brewing syrups are also a mix of invert sugar, caramel and molasses.

And then you have liquid malt extract (LME) and dry malt extract (DME). These are created by making a real wort, through a mash process, and to remove water from it, until either thickened (LME) or completely dry powder (DME). When you mix this with water, you get real wort, which even has to be boiled in the same way as a normal wort, in order to remove the proteins from it.

 

[alice-edmund]

That's a good starter - so how would 1 kg of 'spray malt' or 500g of 'DME' compare with 1kg of Tate&Lyles finest white granulated. Do you need more, or less - and how does it affect the flavours? I know brewing is complex - however I am surprised that no basic summary seems to exist.

 

[Fritzpoll85]

If you have more of the sugar that is fully fermentable, then the yeast will convert more into alcohol, so you end up with a drier taste, less sweetness and so other flavour additions may shine through. Basically, the achievable final gravity is lower, so there is the potential for less sugar in the final beer.

Dextrins will stay in the final beer, as the yeast can't ferment them. The final gravity will be higher and the final beer will have more body to it, with possibly a residual sweetness.

When making wort, the balance of the different sugar types is affected by the mashing temperature, and the grains/enzymes present. So the impact of DME/LME will likely be different according to how the extract was produced and the resulting ratio of fermentables to non-fermentables.

That's my understanding anyway.