Bubbling With Excitement
Double, Double toil and trouble, Fire burn and cauldron bubble, Eye of newt, toe of frog, Wool of bat, tongue of …yada yada yada
I don’t believe I’ve ever broken out the Shakespeare in this blog before, other places-maaayybee- but when you have a great set of lines from MacBeth that you can work into a post, you gotta go with it. Not withstanding the animal body parts, if you’ve ever seen a vat of fermenting grape juice, it remarkably resembles a bubbling cauldron- except, it takes place in a stainless steel tank and it’s not fire that is producing heat- and of course, I’ll get to that. So, what is it that makes that cauldron bubble? Certainly not any witches, because, of course, I just write the blog, I don’t help make the wine. That honor goes to our tiny friends, those guys that turn our grapes into wine and make our bread rise, yeast.
There are many aspects to fermentation- carbonic maceration, microbial activity, oxygen management, temperature, yeast clones, spontaneous fermentations, and other names that make my head hurt to read and write them. Each one worth a post on its own, which means I have a topic guaranteed for at least 6 future posts. However, since it is always best to stick with the basics before complicating things, that’s what you’ll get for this post, the basics of primary fermentation. We begin with sugar, my favorite way to begin things- and end things- and occupy the in-between things. I’ve referred to brix in this blog a few times but just to review, it is basically the measurement of how much sugar is in the grapes- we’re talking the fermentable sugar called glucose. Once the grapes have been picked, de-stemmed and crushed into a tank, the sugar in the grapes is exposed and thus, consumed by either the indigenous (yeast present on the grapes) or introduced yeast. Through magic of respiration (converting oxygen to carbon dioxide) and fermentation, the glucose is turned into carbon dioxide, glycerol, and ethanol (that stuff that gives wine its kick). One of the other by-products of fermentation is heat (I told you I would get to it) which is why most tanks or bins have refrigeration systems to manage the temperature of the fermentation. While stewed fruits can be a desirable trait in some varietals, stewed wine is generally considered unacceptable.
Just so you realize, this is a very over-simplified version of the whole fermentation process. I’m sure some of the
eggheads well-educated people are getting flustered over the fact that I have not addressed glycolysis, the Krebs cycle or nitrogen metabolism. Fear not, if you would like to see any of those in a future post, feel free to comment and I would be happy to a post on any of them as soon as I finish shaving my legs with a dull, rusty butter knife. However, you would make Derek’s day, if he was able to expound on any of these. And what makes him happy, makes me happy- at least, that’s my story and I’m stickin’ to it.
So, fermentation does require some toil- and if we’re fortunate, not too much trouble. Respiration produces the heat, the tank bubbles… Cool it with baboon’s blood, Then the charm is firm and good. And we’re well on our way to producing another outstanding wine- well, minus the baboon’s blood.[jetpack_subscription_form]