Commercial yeast without sulfites

[Dustwheel]

Thinking of using RC 212 for a batch of Grenache from grapes this year. Understanding the chemistry of fermentation and the competing yeast strains that exists on grapes, saccharomyces cerevisiare seem to be the predominant yeast strain that survives above 6% alcohol. Would it be beneficial to pitch the commercial yeast without the use of potassium metabisulfite to retain some of those good bacteria that might help during malolactic fermentation? So I would be using a commercial yeast without potassium metabisulfite with the addition of yeast nutrient. Any thoughts? I would be using sulfites before bottling only. Cheers!

 

[winemaker81]

If you want MLF, not using K-meta up front is something of a requirement, depending on the strain of MLB used. Commercial yeast will dominate wild contenders, so you should be fine leaving it out. After MLF completes, then add K-meta.

 

[Dustwheel]

Another thought / question. Without the use of sulfites, what I need to use the recommended amount of rc212? Or because I'm not suppressing the wild yeast in the first place, would using half the amount of commercial yeast be logical? Of course I would be using yeast nutrient as well. Just a thought.

 

[winemaker81]

Always use the recommended amount of yeast.

Yeast is a living organism, and just a few cells is enough to inoculate a must ... if you have weeks to wait, and are confident that other yeast and bacteria won't jump into a solution that is happy for them.

You want to build a good yeast colony so that it thrives, eats well, and stamps out competition. Commercial yeast is K-meta resistant, so a normal dosage will have no effect upon it.

I've been making overnight starters for over a year now, and the results are unmatchable. This rehydrates the yeast and lets it grow in an environment that is more ideal for it than a must, so you start with a larger colony that reproduces quicker.

 

[Dustwheel]

Always use the recommended amount of yeast.

Yeast is a living organism, and just a few cells is enough to inoculate a must ... if you have weeks to wait, and are confident that other yeast and bacteria won't jump into a solution that is happy for them.

You want to build a good yeast colony so that it thrives, eats well, and stamps out competition. Commercial yeast is K-meta resistant, so a normal dosage will have no effect upon it.

I've been making overnight starters for over a year now, and the results are unmatchable. This rehydrates the yeast and lets it grow in an environment that is more ideal for it than a must, so you start with a larger colony that reproduces quicker.

Thanks

 

[Jusatele]

google an article about yeast starters for home brew beer and you will see amazed at how much they help.
they are easy to do, and if you decide to get into it you can make a stir plate which really helps. that helps a lot but is expensive
Yeast goes through several stages in the fermentation process, the first is multiplying out to dominate the must. the starter just is a huge kickstart on that phase. after that it takes off eating all the sugars. the faster the stage of multiplying the better for you. That is the benefits of a yeast starter.

 

[winemaker81]

For wine, an overnight starter is not difficult, nor is special equipment required.

Put 1 cup water (90 - 95 F) in a clean wine bottle. Add 1 packet yeast, 1/2 tsp nutrient, and 1 tsp sugar. Swirl to mix. Leave in a warm (65 - 80 F) location (e.g., kitchen counter) for a few hours, then place the bottle next to the fermenter overnight. The next morning, swirl to mix and gently pour down the inside of the fermenter so the starter spread as little as possible. Yeast apparently reproduces better in larger groups. Do not stir for 24 hours.

The water starts out hotter than is good for wine, but is more ideal for yeast. By the following morning it has cooled to the ambient temperature of the fermentation area and the must, and there is no temperature shock when adding to the must.