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HMS Irruncible
02-27-2007, 10:01 AM
Beer and wine are both produced by fermentation of sugar by yeast. What's the difference in the process that causes wine not to be carbonated and have a foamy head? Could you make "grape beer" that was carbonated, had a foamy head, and tasted like wine?

pulykamell
02-27-2007, 10:20 AM
Beer and wine are both produced by fermentation of sugar by yeast. What's the difference in the process that causes wine not to be carbonated and have a foamy head? Could you make "grape beer" that was carbonated, had a foamy head, and tasted like wine?

I make beer, not wine, but as far as I understand it, wine is bottled after it has completely fermented out, i.e. the yeast has no more sugars to eat and therefore no CO2 to fart out. With beer, before bottling, one generally adds a small amount of corn sugar, malt powder, or other fermentable to give the yeast just a little bit extra sugar to ferment in the bottle and carbonate your beer.

And, yes, it is possible to make fizzy wine. It's called champagne/sparkling wine.Essentially, adding a little bit of yeast and sugar before bottling is exactly what happens when making sparkling wines under the traditional méthode champenoise. Also, if you've ever had homemade wine, if it's bottle too soon, you will get popping corks and fizzy wine when the yeast consumes the last of the sugars in-bottle.

Mikemike2
02-27-2007, 10:23 AM
Beer and wine are both produced by fermentation of sugar by yeast. What's the difference in the process that causes wine not to be carbonated and have a foamy head? Could you make "grape beer" that was carbonated, had a foamy head, and tasted like wine?

Yes, its called champagne or sparkling wine. Both beer and wine create CO2 during fermentation that causes the bubbles and foamy head. This CO2 only sticks around if it is trapped in a pressurized bottle or container. Wine is allowed to go flat before bottling. Beer is not. The actual process is more complicated, but that is the difference.

Squink
02-27-2007, 10:25 AM
Could you make "grape beer" that was carbonated, had a foamy head, and tasted like wine?Sure. Without the foamy head it's called champagne. You just have to bottle your wine before it's quite done fermenting to make it. Having screwed up, and bottled too soon, and made a horrible mess all over the coal cellar, I should mention that it's best to know what you're doing before trying this at home.
The easiest way to get a head would be to add some albumin and a carbohydrate such as guar gum to your sparkly wine at bottling time.

Getting Good Foam (http://byo.com/departments/1410.html)

CaveMike
02-27-2007, 10:31 AM
To be a little more exact, beer is fermentation of starch sugars (usually malted barley) and wine is fermentation of grape sugar. A wine cooler tends to be fermented malt with fruit flavors added -- so it is really a beer cooler. Likewise, Sake is often called 'rice wine', but 'rice beer' would be a more accurate name. A grape beer would really be a sparkling wine.

In homebrewing, beer is typically carbonated by invoking a second, smaller fermentation after the beer has been packaged. Just after the beer has gone through its prime fermentation, a homebrewer would divy up the batch into bottles with a little bit of extra sugar (malt, corn starch, etc.). The remaining yeast from the first fermentation would consume the new sugar and in the process, release CO2. Since the bottles are capped, the CO2 is trapped and your carbonation.

And on preview I see that I am beat to the punch many times over, but that's OK since I expected it to happen in a beer thread...

butler1850
02-27-2007, 12:33 PM
Vintners (wine folks) also tend to kill the yeast at bottling. I'm not sure what chemical they use, as I prefer to have my beer carbonate (along with my ciders).

To carbonate, I do what the above posts say...

silenus
02-27-2007, 12:36 PM
Sodium Benzoate.

Jayrot
02-27-2007, 12:58 PM
"...that's bad."

Squink
02-27-2007, 01:07 PM
Sodium Benzoate.I think you mean sodium/potassium metabisulfite, as in Campden tablets (http://en.wikipedia.org/wiki/Campden_tablets).

HMS Irruncible
02-27-2007, 01:50 PM
Thanks all.

psycat90
02-27-2007, 02:14 PM
Yes, its called champagne or sparkling wine. Both beer and wine create CO2 during fermentation that causes the bubbles and foamy head. This CO2 only sticks around if it is trapped in a pressurized bottle or container. Wine is allowed to go flat before bottling. Beer is not. The actual process is more complicated, but that is the difference.

Exactly. Some still wines (I find it often in young whites like Sauv Blanc) actually do contain very small amounts of C02. I can feel it as a slight tingle on my tongue. I consider anything more than a tingle a flaw, and almost always a flaw in a red still wine.

This actually came up in one of my classes last night. As home winemakers, my husband and I had to mechanically degas our wine. My husband was curious to know if large wineries ever had to do the same. The answer is yes, sometimes they do, carefully so as not to have a foamy mess spilling out of tanks. And to my surprise ,some commercial wineries add CO2 before bottling, mostly whites to enhance freshness or that 'zip or zing.' (TTB regulations for CO2 in still wine.) (http://www.wineinstitute.org/industry/fedlaw/regs/27cfr_part24/24_245.htm)

Sort of related:
CO2 is released from the wine must during fermentation and allowed to escape the fermentation tank. It's heavier than air and can become trapped in small or confined areas in wineries. This is probably one of the most dangerous aspects of commercial winemaking, and it's not uncommon to hear about a few deaths every couple of years or so in winemaking areas. (See here.) (http://www.findarticles.com/p/articles/mi_m3488/is_11_85/ai_n8576701)

silenus
02-27-2007, 02:18 PM
I think you mean sodium/potassium metabisulfite, as in Campden tablets (http://en.wikipedia.org/wiki/Campden_tablets).

That's what they used to use. Most places today seem to have shifted to Sodium Benzoate as a replacement.

Squink
02-27-2007, 03:15 PM
Most places today seem to have shifted to Sodium Benzoate as a replacement.Ahh, I haven't made wine in a few years.

Tastes of Chocolate
02-27-2007, 03:34 PM
That's what they used to use. Most places today seem to have shifted to Sodium Benzoate as a replacement.

Many of the wine kits I've used still come with metabisulphite and sorbate (I'm guessing that both of those are actually potassium xxx, but the kits leave off the word "potassium").

Instructions/supply list (http://www.brew-winemaking.com/ProductPDF/4102.pdf)