Yeast and Merlot

[winemaker81]

My understanding of EM is that you need to snap a bucket shut with an airlock to keep the wine safe. You said that you punch down daily exposing it to air. I don’t get it. What am I missing here.

That is the recommended process, as it greatly reduces risk of oxidation and other problems. However, @Cynewulf's explanation makes sense. Wine is outgassing for weeks of even months, so there is a constant replenishment of the CO2 over the cap.

The difference is that in a sealed container the CO2 pushes out the air. Yes, the CO2 mixes with the air as it emits from the wine, but over time the constant dilution reduces the amount air to a level low enough to be safe. Folks doing 6 week EM with good success is positive evidence

Punching the cap down daily relies on the constant outgassing to protect the wine, and this layer needs to replenished every time a punch down it done, so the risk level is higher. Cynewulf's results also indicate positive evidence, and as he said, this has been done in France for a very long time.

Me? I'd be ok with doing it for a week or two, but my risk tolerance on the subject is low. In my case, it's probably fine to snap the Brute's lid on and leave it for a week, as excess air will push out through the imperfect seal. It's not one-way like an airlock is, so I'm not comfortable going for a longer period.

 

[distancerunner]

My reading tells me that CO2 is coming out of solution. How much and for how long is the question. Personally, since my science background is monkey see, monkey do, I wouldn't know where to look for the equation let alone know if there is an equation to calculate off gassing.

That's why we blanket EM with argon weekly.

As far as punching down goes, once the wine goes dry it doesn't lift much of a cap. Mostly it looks like skins suspended in liquid. We don't bother to give it so much as a stir after a week or so.

distancerunner = lazy winemaker