Naked Science Forum

Non Life Sciences => Chemistry => Topic started by: dgt20 on 21/02/2018 08:24:18

Title: Is wines 2nd fermentation and malolactic fermentation the same thing?
Post by: dgt20 on 21/02/2018 08:24:18

Is wines 2nd fermentation and malolactic fermentation the same thing?

Title: Re: Is wines 2nd fermentation and malolactic fermentation the same thing?
Post by: Colin2B on 21/02/2018 08:49:19

No, it is the conversion of malic acid to lactic acid which tastes better. It can be a secondary fermentation or part of the primary but it is a bacterial action so not part of any primary or secondary yeast fermentation.

Title: Re: Is wines 2nd fermentation and malolactic fermentation the same thing?
Post by: dgt20 on 21/02/2018 09:07:42

Quote from: Colin2B on 21/02/2018 08:49:19

No, it is the conversion of malic acid to lactic acid which tastes better. It can be a secondary fermentation or part of the primary but it is a bacterial action so not part of any primary or secondary yeast fermentation.

So its an optional fermentation step that happens either during primary fermentation or secondary?? In other words not essential?

Title: Re: Is wines 2nd fermentation and malolactic fermentation the same thing?
Post by: dgt20 on 21/02/2018 09:25:19

Also what would be the chemical equation for it or would it be the same one as the primary fermentation one where sucrose reacts with yeast as a catalyst where ethanol and co2 is produced

Title: Re: Is wines 2nd fermentation and malolactic fermentation the same thing?
Post by: Colin2B on 21/02/2018 10:54:38

The yeast gives out enzyme which breaks down starch into simpler sugars which yeast feeds on excreting CO2 and alcohol.
In the malic acid case it is bacteria feeding directly on the acid, CO2 is producd plus lactic acid.

Title: Re: Is wines 2nd fermentation and malolactic fermentation the same thing?
Post by: chiralSPO on 21/02/2018 23:53:54

Quote from: Colin2B on 21/02/2018 08:49:19

No, it is the conversion of malic acid to lactic acid which tastes better.

Wait, you are saying that lactic acid tastes better than malic acid in wine?

I haven't compared the two directly, but I happen to enjoy the taste of malic acid in fruity contexts (in sour apples and candies like Sour Patch Kids), while I like lactic acid in more savory contexts (Greek yogurt and sourdough bread).

I would have thought that wine would be better with fruity acids over cheesy acids...

Title: Re: Is wines 2nd fermentation and malolactic fermentation the same thing?
Post by: Colin2B on 22/02/2018 08:19:59

Quote from: chiralSPO on 21/02/2018 23:53:54

I would have thought that wine would be better with fruity acids over cheesy acids...

Well, no accounting for taste eh :)

Like you i enjoy the sharp taste of green apples (never come across Sour Patch Kids!) and love sourdough + greek yog.
Most malic fermentation takes place in red wines + Chardonnay, and apparently gives then a smoother buttery taste. I suppose we would have to taste the wine before and after to understand the difference.