I want to explore sur-lies aging for a red wine (zinfandel) but am not always able to adhere to a strict schedule. How tolerant are mixing schedules to time changes? What kind of schedule is common for red wine? One per month for 8 months? Do I risk too much oxygen exposure during each mix? I'm trying to naturally achieve the effect of an additive.
A Sur-Lies is the process of allowing a finished wine to continue to sit on the lees in order to extract flavors from them. Mixing is used to accelerate the process of flavour pickup and break down of the Lees on which the wine is sitting.
For a small batch I am not sure the mixing is a vital as for larger commercial operations. Furthermore, I don't think you should be opening our vessel to do the mixing, a good sloshing around should stir up the Lees into the body of the liquid and allow for the desired mixing.
Regarding scheduled mixing if you are trying to replicate an exact previous batch then temperature control and scheduled are far more important. If you just want the benefit of the process then an article I found in Wimemakingmag.com suggests:
• Stir once per week for eight weeks
• Stir once per month for one year
Replace stir with slosh about, and week/month with week-ish and month-ish and I am sure you will have a delicious wine.
I would advise against opening to mix as in traditional method they just roll the barrels to mix the Lees through the wine.
Here is some advice from a former winery owner (mine) and having scored a 93 in Wine Advocate on a Red Rhone Blend. I think you are mixing up sur-lie aging of white wine and red wines. I don't know any winemaker that mixes up the lees of a red wine to enhance mouthfeel, which is what you are doing with white wine, mostly chardonnay.
There are two types of lees: Gross and Fine. You want to age on the fine lees. Gross lees are produced right after pressing and contain lots of junk. Stems, grape skins, bugs, seeds, etc. Fine lees are what's left after you rack your wine the first time. I typically did this several days after pressing and the big layer had compacted on the bottom of the tank. Don't worry, there is enough fine lees still floating around the tank after the first racking. Then it's nighty night, time to put the wine to rest for a long time. In a barrel, I would have to top up and adjust sulfite levels every month or so. If this is in a carboy, you will not need to top up and maybe adjust sulfites every few months. But do not stir, you will introduce too much oxygen. Bottle when you are ready!