March 4, 2019 | Angela Chapman
Let the Cauldron Bubble
It is harvest time again! And harvesting means making more amazing wine.
I recently got the pleasure of helping out with the crushing and destemming of some newly harvested grapes.
|it's a dirty job....|
I have to say that I got to do the coolest job there, literally. When the grapes arrived in their bins it was my job to spread dry ice pellets on top of the grapes.
|Selfie with dry ice. Because Science!|
Dry ice is solid carbon dioxide and is -109.3ᵒ F. You have probably seen it in action in spooky movies. When dry ice sublimates (heats up and goes from a solid straight to a gas) it makes what looks to be really cool fog that flows across the floor. It’s really just carbon dioxide that is so cold you can see it.
|Movie creepy floor fog|
That’s cool and all but why was I putting it on the grapes? Well it does a couple different things. The first is the most obvious; it cools the grapes down helping to preserve them while they are waiting to go into the crush. Because carbon dioxide is heavier than the air around it sinks to the bottom of the bin and envelops the fruit preventing any bacteria growth and unwanted early fermentation from wiled yeast. The dry ice also creates micro cryomaceration. A process that flash freezes the grapes in direct contact with the dry ice. This has the result of breaking down cell wall structure and releasing more anthocyanins (color pigment), phenolics, and flavanoids. That is a complicated way of saying that it gives the wine more character and complexity.
The end product is better wine but the process was not only fun to watch but also a little reminiscent of Halloween.
- Angela, WSET III
By Angela Chapman