Different colored layers in must

Hello,

First time kit winemaker and first time poster to this or any forum. I pitched the yeast into a Cru select Australian Shiraz/merlot/cab kit on 3/27/13. Starting specific gravity was 1.092 and temperature of the juice was 24 C. The lid on the primary fementer fits loosely. The airlock is on the lid, but obviously no bubbles because of the loose fitting lid. Fermentation started around day 2 based on observed movement and foaming of the must.

My question is that I can see a two distinct layers of must in the primary fermenter. The approximately top 6 inches of must is a lighter purple, and the remaining bottom layer is a darker color purple. My first thought was that was the yeast working its way down the fermenter. However as the days progress, the separation or depth of the lighter and darker colored layers has not changed. It seems to me when it is time to measure the specific gravity to determine if the fermentation has slowed to the point I need to transfer to the glass carboy that I could potentially get different readings based on whether the sample was drawn from the lighter colored top layer or the deeper colored bottom layer.

1) What is causing these different layers?

2) Should I stir prior to measuring the SG ? It seems like by doing this I would bring all the sediments that I want to fall out back into suspension.

3) At any point should I seal the lid of the primary fermenter?

Any feedback will be appreciated.

Regards

Stir a couple of times a day, you dont want layers, you want everything the same. Good luck, WVMJ

The layering in just normal settling but you need to stir it to keep things mixed up. During the primary you want favor and color extraction from the sediment. I stir two to three times a day for the first three to four days, then let it set until transfer.
When you stir it, don't whip it but just a gentle stir to move things around.
I leave my lid loose until the gravity gets to around 1.020 to 1.010 then transfer to a carboy with an airlock. that is where you want the sediment to fall out.

You may see the layering in the carboy too. It's just things with different densities settling out at different rates.

Stirring helps move yeast and nutrients around. Allows a flavor to develop from sediment. It also releases CO2 reducing eruptions when you transfer or stir later on. It also reduces the stress on the yeast as their environment becomes toxic to them…less sugar and nutrients, many yeast competing for food, % of alcohol increases to name a few.

Most will stir frequently until 1.010-1.000. Here some will transfer to Carboy while others secure in bucket with an airlock thru final fermenting. CO2 given off protects the must from air.

Once fermentation is thru I rack to clear with sparkolloid.

There isn't an exact science to wine making but some procedures should be followed for an increase success rate.

Should you always stir the must? Even with kits? I usually just let it sit...

Always gently stir your must. Once it reaches @1.000 add an energizer usually 1 teaspoon per 6 gallons, snap on a lid with an airlock or rack to Carboy with airlock. Leave it alone a few days. It will finish fermenting and much sediment will start to fall.

If you are making a kit you may not have an energizer like super ferment. Don't worry. Those are like vitamins for the yeast.