Yeasts and the sugar they eat

[tgirl23]

Hi!

I'm about to dive into a new hobby, and collect ingredients for my very first batch. However, I want to make sure I got everything right, and I'm a bit uncertain about the right form of sugar to use. I plan on using the Alcotec 48 yeast, and the recipe says "just add sugar and water". However, I was under the impression that yeast mainly digests simple sugars such as dextrose and fructose, and if I remember my school chemistry right, ordinary table sugar is a disaccarid, consisting of a molecule made from two simple sugars.

So, does it work with table sugar too?

[Dnderhead]

white sugar ," sucrose" witch is--glucose and fructose, both yeast will consume, some "convert" with acids like citric, this prevents recrystallizing.

[rad14701]

Welcome to the forums, tgirl23...

Sounds like a quick study of distillation theory, sugar, yeast, and nutrients would be of benefit... We have several recipes that are almost as easy as using turbos, produce almost as much neutral spirits, ferment almost as quickly and without the off smells and tastes turbos impart, require less post ferment and post distillation fuss, and cost less per batch...

What type of still will you be using...???

Good luck...

[tgirl23]

@Dnderhead: well, sucrose isn't just a mix of fructose and glucose, it's a molecule made from both, and it needs to be split up for further processing. The question is whether the yeast can do that on itself or not. Also, I thought that the acid was for regulation of pH value...

@rad14701: thanks for the welcome. I did study the recipes, and they're fuzzy about the sugars. Some say "dextrose", some say "sugar" without any further qualification. Some recommend addition of an enzyme called amylogukosidase for splitting up the disaccarides into monosaccarides, some don't. So I wonder what the bottom line is: does it make a difference or doesn't it?

Also, I'm fully aware that turbos are the worst choice in terms of taste of the end result. I aim for fruit or grain mashes eventually, but wanted to cut down on the number of variables for my first experiments. Getting the destillation process right will be my first focus. The turbos readily contain all the nutrients needed, and allow me to start running my still soon.

The still is a 3 gallon stainless steel pot still.

[rad14701]

From the research I've done, as well as reading the research of others, inverting the sugar definitely makes a difference... I've found that my ferment times are drastically reduced when I invert the sugar as opposed to not inverting...

I just ran a couple Gerber washes as a base, without inverting, and hope to put down a couple more using invert sugar to see the difference... My projected guesstimate is that ferment times will be reduced to less than half that of non-invert sugar... The ferment times on these base washes were the longest I've ever had for Gerber... They finished to dry at 12% and 14% but took what seemed like forever... I like having ferments finish in 36 - 72 hours a whole lot better... Compare to that the fact that I put down a wash with invert sugar and boiled All Bran cereal and it finished to 12% and cleared in 4 days and I distilled on the 4th day...

[HookLine]

Hi tgirl, and welcome.

@Dnderhead: well, sucrose isn't just a mix of fructose and glucose, it's a molecule made from both, and it needs to be split up for further processing.

Correct

The question is whether the yeast can do that on itself or not.

Yes it can.

Also, I thought that the acid was for regulation of pH value...

It is.

@rad14701: thanks for the welcome. I did study the recipes, and they're fuzzy about the sugars. Some say "dextrose", some say "sugar" without any further qualification. Some recommend addition of an enzyme called amylogukosidase for splitting up the disaccarides into monosaccarides, some don't. So I wonder what the bottom line is: does it make a difference or doesn't it?

The main sugars we are interested in are fructose and glucose, or their combined form, sucrose. Glucose comes in two forms, right and left handed (stereoisomers). Dextrose is the right handed version, and is the one we want, as the left handed version is biologically inactive and unfermentable.

Enzymes are not used by stillers to split sucrose into glucose and fructose. Heat and acid will do that. Or you can just leave it for the yeast (which does make its own enzymes to split the sucrose). You can buy dextrose from the brewing shops, the beer and wine guys use it a lot, as it gives a cleaner ferment than sucrose or fructose. But it is expensive.

Enzymes are used by stillers to split starches into smaller fermentable saccharides.

Bottom line: If you are using plain sucrose, don't worry about using enzymes. If you want to split the sucrose, add some citric acid to some water, add the sugar, heat to a simmer for 15 minutes. The heat and acid will do the job. But many do not even do that and have no trouble fermenting. Yeasts have been around for a gazillion years, and a pretty tough little fellows. Splitting the sucrose will probably speed up the ferment, as the yeast do not have to do that bit of the process, and can get right into proper fermenting.

Also, I'm fully aware that turbos are the worst choice in terms of taste of the end result. I aim for fruit or grain mashes eventually, but wanted to cut down on the number of variables for my first experiments. Getting the destillation process right will be my first focus. The turbos readily contain all the nutrients needed, and allow me to start running my still soon.

Try running the Turbos at half the recommended rate, and keep the abv down to 10-12%. You will get a much cleaner result, and faster too.

[tgirl23]

Ok, re-reading the literature I find that acid and heat can indeed be used to split up saccarose into simple sugars. So it's not just about pH.

Thanks for all the answers, guys, really helpful!