Wednesday, December 5, 2007

Secondary fermentation.

The thing about making wine is that you are never really done with it until it lands in the bottle. Then, of course, you have to distribute and sell the wine. So, I guess you're never done!

Yes, the 2007 harvest is over for us and we can get a decent night's sleep. The growers are happy that the vines are going dormant. The cellar crew is happy that they can cut back their work hours. And we are happy because we have been gifted this year with over 40 barrels of outstanding wine. Now, the watching and the waiting begins - but as it is seemingly unavoidable - the work continues.

When the sugar from our grapes is consumed by yeast and converted to alcohol, wine has been made...but not completely. Many would claim, "Woohoo its done!"..."Let's Party!" but unfortunately many holidays have been canceled because of the next step - the wine needs to finish yet another fermentation!

So, around Christmastime last year I found myself tending to barrels like a shepherd tends to his flock. The secondary fermentation was taking an extraordinarily long time to complete and I could not let the wine out of my care for a second...I worked in the cellar all through the holidays.

However, this year will be different and the '07 Vellum will cooperate because I want to get home to Pittsburgh for Christmas and some German sauerbraten and dumplings with blackened butter! Errr...I digress... but I hope my mom is reading this!

So...Anyway, we have taken care of the sugar but now we need to deal with the acid - in particular the malic acid.

For those of you who are unfamiliar with malic acid, try to think about what you are tasting the next time you bite into an apple. A large portion of that tangy sensation is malic acid.

In grapes, it is available in large quantities as well but it gradually decreases as the grapes reach maturity. Unfortunately though, the acid never completely disappears. Herein lies a winemaker's problem. A spontaneous secondary fermentation is looming because the malic acid is a delicious food for naturally occurring lactic bacteria. It is easily metabolized (consumed) by this bacteria and converted into lactic acid and carbon dioxide gas.

Lactic acid is an acid found in milk products. It is stable and hardly noticeable in milk and it has a similar effect in wine. But here's the rub (and there always seems to be one with wine!) - if the wrong bacteria starts eating the malic acid...spoilage occurs and the bacteria release a potpourri of odorous waste into the wine! This can ruin your wine and make it nearly undrinkable.

But if you introduce a beneficial bacteria (Oenococcus Oeni) to feast on the malic acid...you can considerably improve the wine's quality by lowering the overall acidity. This makes the wine more supple and stable.

It also adds an extra bit of security at bottling. In essence, if there's a yeast or bacteria cell that sneaks into the bottle after it is sealed...it won't ruin the wine...

With no residual sugar and no malic acid - there is no food for the yeast or bacteria to consume and no negative effects will occur.

The 2007 Vellum has been inoculated with Oenococcus Oeni at 68 degrees Fahrenheit to start the secondary fermentation and it is on pace to be finished late next week. When it is finished, the wine's heavy sediment will be removed, the barrels will be topped off and I can keep my appointment for Christmas dinner!

Oh and if there's anyone who can successfully pair sauerbraten with a wine, please give me a shout - yet another mystery to unravel!

Merry Christmas everyone!

~ Karl

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