So then back to my previous question...
With respect to the enzyme that the yeast uses to break sucrose down, I wonder what the amounts of this is and it's flavor contribution that would lead one to use an inverted sugar over table sugar.
Here's a little about sugar conversion, etc. you might find interesting:
Inversion, Invert Sugar and Invertase
Invert sugars are monosaccharides, dextrose and fructose, that generally comes from sucrose, a disaccharide.
This is done by hydrolysis, and can be accomplished by heat, acid or the actions of an enzyme known as "invertase." Candy makers generally perform the latter process to make their invert sugars, and their source of invertase is our good friend
Saccharomyces cerevisiae, aka brewer's yeast. S. cerevisiae makes invertase naturally.
How does invert sugar affect beer? Little if any flavor contribution, but what it does do is lighten the body of a given beer while increasing the alcohol content.
A side word about dextrose: it is more commonly called glucose and is the chief source of energy in the body and the main sugar that the body manufactures. Cells require insulin to utilize glucose.
So how does sucrose affect the flavor of beer? It must be broken apart before the yeasts can use it. As a complex sugar, it's a little harder for the yeast to "chew on" table sugar (sucrose) than it is for them to eat up dextrose or fructose.
A complaint often heard in homebrewing circles is that using table sugar in beer-making results in "cidery" beer, or sometimes even in a major amount of acetyaldehyde (green apple) being present. Acetylaldehyde[FONT=Verdana, Arial, Helvetica, sans-serif]
is an intermediate compound in the formation of alcohol, and often results from using too much complex sugar that the yeast cannot fully convert. "Cidery" flavors are also indicative of acetylaldehyde, or aceto-bacteria, another problem entirely.[/FONT]
The rule pretty much became 'avoid all table sugar' for a lot of people. Others say that the aforementioned defects most likely come from poor yeast due to a under-pitching, a lack of other necessary yeast building materials in the wort, or even a lack of oxygenation. That makes sense if you think it through: not enough, weak or "tired" yeast won't finish its job properly and it can leave behind intermediate compounds that are quickly identified as off-flavors.
You can use table sugar and make great beers. But don't believe me, look around at some famous Belgian breweries who are world-renowned for their beers and you'll find a sizable number user table sugar instead of invert!
Table sugar can be used in small amounts in a healthy wort with few problems. But as the old advice goes about aspirin -- two is good for a headache, but don't take the whole bottle -- one should not rely on table sugars too heavily. Doing so courts the problems cider-beer and green-apple beer.
Me, I find it dead simple to make invert sugar and often do when I am brewing up a Belgian-style brew. Recipes galore exist all over the place, and it's only a short bit of work to make the stuff.
