First steps in winemaking / intention to ferment with wild yeast / various questions / log

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SGX

Junior
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Hello,

I am making my first steps as a winemaker, learning mostly on-the-go by talking to other homebrewers.
The fruit was collected from an old, barely worked vineyard. The vineyard is supposedly Cabernet Sauvignon. There was a large variation between the quality of the grapes between vines and among the produce of a vine itself. For instance, we had half shrivelled/raisin-like fruit, and half decent one in a given cluster. There are also a few white grape vines. We did put in the baskets the produce of two vines which later were exposed as “American vines” by a passing by acquaintance, apparently as the vineyard has not been properly tended, additional vines grew from the roots on which the CS was grafted and camouflaged themselves amongst the other vines. All in all, from the 200 kilograms collected, there is a portion of 5-10% mystery white grape (Cote Rotie anyone? :)), and 1-2% American vine.

It is my intention to do a fermentation with wild yeasts and not adding sugar. The latter seems easier as the brix count on the liquid is 21.1. I am very eager to hear your thoughts, especially on the former, and to get a better understanding on the case please see below a succinct timeline.

21 September
Noon to evening - harvest - 200 kg grapes. Supposedly cabernet sauvignon, a few white vines (5-10 %). Possibly 2% American vitis.
315 L fermentation vat (stainless steel).
Throughout the evening – crushed all the grapes with a manual machine altogether, tried to get rid of most unripe grapes by a hand selection. Included the shrivelled, amarone-like grapes and added some stems from the best looking clusters.
Put potassium metabisulphite as per recommendation. Recommendation coming from people who use commercial yeast, nutrients. Put approximately 8 or 10 grams for the 200 kg of must. The instructions on the package read 5-10 grams for 100 litres of decent grapes, and 10-20 grams for grapes with some rottenness. Mine are definitely not picture perfect and I did put some, yet three / four times less than the amount I should have by the textbook.
Put a bottle full of ice and water in the middle of the must as an instrument for "cold maceration". Juice was definitely below 15 degrees for the next 12 hours.

22 September 12:00. Took out the bottle, didn’t replace it. Was advised to replenish the bottle with ice and water for 3 days for more extraction. However, I wasn’t sure of the temperature of the must, and didn’t want to risk for it to have gotten above 15C and to disrupt an already started fermentation process.
Stirring and pumping over (remontage) 2 times every day, starting at this moment.
Since the evening of the 21st, the fermentation vat lid was on.

23 September 12:00. 24 hours ‎afterwards, nothing. Took the lid away and put a blanket as advised.

24 September 12:00. Stirring, pumping, nothing happening inside the fermentation tank.
The colour has gotten from a very light brown the night we put it all in the fermentation tank, through a rose, and is now a proper ruby colour.
The temperature in the room is constant 22C and the humidity is 50%. First day I had the room with all windows/doors closed, the next two days I have allowed some circulation of air from the outside, however now temperatures are going down and depending on your advice may leave a window open with a heater on.

Did I make a mistake putting the potassium metabisuplhite before the fermentation? Could it have disrupted the yeast present in the grape skins? The last times the grapes were “sprayed” was late June, and they haven’t been washed. Was having the lid on for the first 24 hours – the yeast not having abundant access to oxygen – a mistake?

I would much appreciate any thoughts, comments, ideas.
 
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there is a possibility that the K-Meta has killed or at minimum stunned the wild yeast. I would wait at least another 48 hours monitor the brix and see if fermentation starts. be aware of any off odors such as rotten eggs. if nothing starts by then inoculate with a commercial yeast at rate of 1 gram per 4 liters.
 
there is a possibility that the K-Meta has killed or at minimum stunned the wild yeast. I would wait at least another 48 hours monitor the brix and see if fermentation starts. be aware of any off odors such as rotten eggs. if nothing starts by then inoculate with a commercial yeast at rate of 1 gram per 4 liters.
Tomorrow am harvesting the other half of the vineyard, and processing to the other identical fermentation tank. Worst case scenario, if nothing happens in vat1, and am to use a commercial yeast, will this somehow influence the wild fermentation in vat2? Could it be that the must sitting idle in vat 1 "catches" on the wild yeast in vat2?
Regarding vat2, basically I shouldnt add K-Meta to not disrupt the wild fermentation? Is there however something else to do/put in order to evade the issues of not adding K-Meta?
Also, I read somewhere that in a place where commercial yeasts are used, after a period, wild yeasts wont work anymore. Could you please comment on that as well?
Would appreciate also any feedback regarding temperature and air circulation; the cold maceration phase - does it also harm wild yeast?
 
ok lets talk about what is wild yeast. it can be resident on the skins of the grape and can also be floating in the air. any use of the K-meta will kill these yeast. adding commercial yeast to your first batch will not affect the second batch as long as any tools used for the first batch are not used on the second batch without being sanitized.I add about 3 grams of K-meta and 11 grams of tartaric acid to a gallon of water. place in a spray bottle and spray any tools used to touch the wine either vat..there is no alternative to using K-meta if you wish to sustain a wild fermentation use of commercial yeast will not affect any wild yeast that exists in the environment . over time the initial wild yeast is overcome by the commercial yeast in the air, which I now call feral yeast. cold maceration will not affect any yeast it essentially keeps them in hibernation until the temp is raised to at least 65 degF. Cold maceration is keeping the must at 55deg F or lower for a few days. can be accomplished by added frozen jugs of water into the must. the purpose is to increase the color. do for only a few days as color extraction is done by that time. keep string every day at least twice a day.keep vats covered with a cloth
 

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