h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

I was puzzled to see someone making what they described as a non-alcoholic sparkling wine. As far as I could see, they were fermenting it; the ingredients were sealed in a bottle for several days (weeks?) until it became fizzy. I would have thought the presence of the gas implied that alcohol must have been formed. Is that right?

(They certainly didn't add gas to it)

It's possible to make fizzy drinks with a very very low alcohol content, eg home-made ginger beer or elderfower cordial, but they are not completely alcohol free.

Another possibility is a malo-lactic ferment, where malic acid converts to lactic acid, supplying a light sparkle, but I'm not sure whether or not that only occurs in already fermented, ie alcoholic, wines.

Did the someone use a yeast culture?

>>Did the someone use a yeast culture?

Whether they added one or not, wouldn't yeast be needed to create a sparkle? It is simple enough to allow wild yeasts to cause fermentation; I use them when I make sourdough bread.

There's a very old Finnish beverage, usually made for Walpurgis, named Sima.

It's made from lemons, brown sugar, granulated sugar, raisins, yeast and water. It should be consumed very soon after the raisins have started floating. It starts out like a fizzy, non-alcoholic drink, but after about a week it starts turning into an alcoholic drink (growing even fizzier).

it depends on the yeast, if it's a bread type yeast it will produce lots of co2 and very little alcohol as the level of alcohol will kill the yeast

home brewing mead i used a bread yeat and from a potential ABV of 16% i only get 8% and that is after 2 weeks fermentation so 8% alcohol is about it for my brad yeast

champagne yeast on the other hand can bring in ABV of around 16-18%

so a high co2 yeast with very little tolerance for alcohol could be what is used

Just as you say, with yeast fermentation, you are feeding the yeast sugars, and they are producing alcohol and carbon dioxide bubbles. So if there are bubbles, there is also alcohol. Perhaps not as much as with , but there is some.

As hygienicdispenser points out, there is malolactic fermentation.
So sugars go in, carbon dioxide and some acids come out.

Here is an explanation of the process:
http://www.eckraus.com/home-wine-making-malolactic-fermentation.html

OK, thanks for the replies. Is there a simple way to show these people that alcohol is present (before they get upset that I don't want my kids to drink it)?

The level of alcohol is likely to be less then 0.5% so it counts as being "alcohol free".

>>The level of alcohol is likely to be less then 0.5%

Why?

It's just a hunch, but I'm usually right on these hunches.

Unless fermentation is very carefully controlled, the alcohol reacts further to produce more fizz (carbon dioxide) and acetic acid (the main component of vinegar), making the drink taste sharp, but leaving very little alcohol in the mix.

does wine making need to be carefully controlled? surely not if it is done by bacteria ?? they tend to kill themselves in the alcohol they produced themselves and that's the end of the process.
As far as I know either impurities in the bacteria (yeast?) or overdose oxygen will produce acetic acid.

But then I never made wine..

Wine/alcohol fermentation is done by yeast not bacteria. And yes around 20%ish ethanol will kill them.

Vinegar also is made by a different organism again - this time, yes, bacteria - acetogenic bacteria (acetobacter species usually) specifically.

The acetate production of these is fairly unique to their biochemistry and produces a strongly acidic solution that most other organisms cannot tolerate.

(Fortunately for me here, one of my students has recently written me a dissertation on vinegar production )

In principle, yes, alcohol will air-oxidise to acetic acid but this is going to be slow and you'll get pretty nasty tasting stuff, I've not heard of it generally being a problem in brewing myself but I could be wrong.

i was told beware fruit flies as they carry the bacteria and if they contaminate your brew, after the fermentaion process all you have is only fit for chips!!!

>>The level of alcohol is likely to be less then 0.5%

Why?

Because if the bottle hasn't blown up, then the level of alcohol is just about where Gnomon said, or only just a tad higher. And if the bottle did blow up, then you have a sticky mess to clean, but very little drinking to do.

Think of the yeast as a little machine that produces two products which stay in proportion to each other. One is the gas that makes the soda a bit fizzy and the other is alcohol.

The only way to get enough alcohol to call it beer or wine is to let the fermentation go quite a while. We let beer ferment a minimum of 10 days before bottling. During that fermentation process, the alcohol stays with the beer, and the carbon dioxide is permitted to escape the vessel.

There are two ways to do this. A traditional method of fermentation uses an open vessel. The modern method is to use a fermentation lock that allows the gas to escape and prevents any wild yeast or other contaminants from entering.

Bottling involves sealing the contents of the bottle so that gas can't enter or escape. The gas produced stays in proportion to the alcohol, so only enough gas to make the soda fizzy and only very little alcohol, no more than eating quite ripe fruit or drinking orange juice.

> does wine making need to be carefully controlled?

That is an awesome question, #5 and every vintner has an opinion. Some like a more freewheeling approach, others like to control every aspect for a predictable flavor profile.

> surely not if it is done by bacteria ?? The bulk of the fermentation is done by yeast, which produces alcohol. Some wine-making processes involve malolactic as well, but this is done to enhance the flavor of some wines.

As far as I know either impurities in the bacteria (yeast?) or overdose oxygen will produce acetic acid.

Acetobacter bacteria makes acetic acid that is vinegar. You can make your own vinegar by adding mother of vinegar to wine. Sometimes you see the mother of vinegar in the bottom of a bottle of vinegar; it is the stringy slime. Or you can buy some at a home-brewing shop.

> But then I never made wine..

Oh, try it. It's fun!

I'm seriously considering cheering up a section of front fencing in my house with grapevines - it's south facing and the strong sun and heat tends to nuke most other things. I believe grapevines grow well in the heat so I do indeed look forward to trying myself.

Not sure I'll make wine with it though - probably just eat the grapes, but we'll see...

>section of front fencing in my house<

Rather, outside the front of my house I'm not into indoor grapvines just yet - only when I can afford my roman villa in Tuscany

Here's an example of where Wikipedia is wrong...

http://en.wikipedia.org/wiki/Low-alcohol_beer

In Britain, if a drink has less than 0.5% alcohol, it is classed as 'alcohol free'. You can trust me on this, as I'm sitting typing this while I read the label on my Erdinger Alkoholfre bottle, which (after research) has an alcohol content of 0.4%

'Alkoholfre'

I've obviously had far too many! 'Alkoholfrei'