A little dust on the bottle, revisited

A couple of days ago, my dad and I stopped by our friend's house, in whose garage the primary fermentation of the grapes is taking place. By that time, they had already been fermenting for about four days. The smell was pungent, but it brought back a lot of memories from when my dad made wine when I was little. It smells, well, it sorta smells like rotten grapes. But I happen to like it. The vat was warm to the touch. About 74 degrees Fahrenheit, according to our infra-red thermometer. The grapes themselves were a tad warmer. I guess the yeast feeding on the grapes is an exothermic reaction. That is, it releases heat energy. I took some photos. They're not great quality, as I took them with my phone, but you can sort of see what the crushed grapes look like about halfway through the primary fermentation process: Here's a shot of the grapes just sitting in the vat. The whole mixture is beginning to take on the dark purple color that most people would recognize as the color of wine. The juice itself is really weird looking. It's surprisingly opaque, and it's almost a lavender color. You can actually hear the juice in the vat bubbling as the fermentation takes place. The bar sticking out of the muck is a metal bar we use to aerate the mixture. We just sort of push it in and out, reaching all the way to the bottom, in order to make sure that the bottom most grapes in the vat are getting their fair share of oxygen. This has to be done several times a day. It's weird, when you break the surface of the grapes with the rod, and some of the juice bubbles up to the surface, it's bubbling so fiercely it almost looks like it's boiling.
Here's a shot of our friend aerating the mixture with the metal bar.

It's been a pretty interesting experience so far, and I'm quite looking forward to the next few steps of the process.