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Today I was exploring a question that has been on my mind, and I found this: https://www.researchgate.net/figure...ion-changes-in-key-metabolites_fig1_332733632 (scroll down and click on "Download full text" to get the entire article.

There is a lot of information here that is not of immediate interest to me. But I found section 4 "Chronological Life Span in Wine Yeasts" quite interesting. It included this chart:
View attachment 95875
In the accompanying text I found this comment:

From this I learned that the main need for nitrogen is during the exponential growth phase. But most of the alcohol production takes place during the stationary phase, when the yeast is no longer reproducing. That is why the SNA used by mead makers stops adding nutrients at the 1/3 sugar break, when 1/3 of the sugar has been digested by the yeast. The goal is to have a healthy yeast population by the end of the exponential growth phase, so that the existing yeast can finish the process of fermentation. I have not yet found a clear statement on what nutrients the yeast need once they reach the stationary phase.

The green and red text is explained here:

In other words, the items in green text help the yeast to stay alive and keep working, and the ones in red help with aging.

I thought you would find this interesting, so I thought I'd share it here.
Whites, 1/3 sugar is where the yeast population maxes and they switch to anaerobic.
Reds, it depends. Again oxygen isn’t needed after 1/3 sugar. The mixing of skins to prevent mold growth means you have your tank open. In this case after pressing.
All in all oxygen is the enemy of alcohol producing acetaldehyde. Unless I could do a novel system as fermentation in a bag sooner rather than extending past zero sugar.
 
Later this week I am picking up some fresh juice. Not knowing exactly when, I may have to leave town on a family emergency. So here are a couple of scenarios. Juice arrives and I need to leave the next day. Do I try to split the six gallons into jugs and refrigerate? Scenario 2. I pitch the yeast and need to leave just as it gets going or one to two days later. Do I snap the lid under airlock even though SG is still high? Appreciate any input.
 
Later this week I am picking up some fresh juice. Not knowing exactly when, I may have to leave town on a family emergency. So here are a couple of scenarios. Juice arrives and I need to leave the next day. Do I try to split the six gallons into jugs and refrigerate? Scenario 2. I pitch the yeast and need to leave just as it gets going or one to two days later. Do I snap the lid under airlock even though SG is still high? Appreciate any input.

I would refrigerate it. Throw in a dose of Kmeta.

Putting the airlock on will restrict oxygen access, you could be at risk for issues if that stresses your yeast. Also you won’t be able to add nutrients at the 1/3 sugar depletion point.
 
I would not start fermentation until I knew for sure that I would be around for the next five days at least to punch down and monitor the fermentation temps. Best to refridgerate the juice until you return from your family emergency. A neglected fermentation is a sad fermentation.
 
I would refrigerate it. Throw in a dose of Kmeta.

Putting the airlock on will restrict oxygen access, you could be at risk for issues if that stresses your yeast. Also you won’t be able to add nutrients at the 1/3 sugar depletion point.
I would refrigerate if I knew I was leaving immediately. It could turn out that I’m not needed out of town for a couple of weeks. That’s the dilemma.
 
I would refrigerate if I knew I was leaving immediately. It could turn out that I’m not needed out of town for a couple of weeks. That’s the dilemma.
How are you going to travel? If by car, could you take the fermenters (divided into smaller batches for ease) along? I’ve hauled fermenting wine for up to 6 hours each way with no ill effects.
 
Some people bring their pets on car trips with them, so... ;)
I like it! My pet cerevisiae. Or, better still, my emotional support cerevisiae (that way you can travel by plane or patronize nice restaurants)... or my seeing eye cerevisiae who identify as dogs!
 
Thank you for all the serious advice. Still in a holding pattern.
Sorry for my nonsense (that's just who I am). On a serious note, freezing juice is still an option (I don't know if you have a freezer or not). You just don't want to freeze too long as it may precipitate out bitartrates and you would have to adjust acidity.
 

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