I believe I'm up against a brick wall here- I have been unable to produce dry wine, red or white, regardless of what I do. No matter what when I go to taste said wine there is a hint of sweetness upon the tongue.
I've a 'restarter' set here and the yeast won't work on it, so even blending that in to try and consume the last partial percent won't work. The clinitests say just around 1% RS, give or take.
Any suggestions for this next year?
What SG are you starting at?
Keep the gravity down to 1.085 - 1.090 tops. Use a champagne yeast. Make sure you have adequate nutrient and stir the must twice daily over the couse of the most active fermentation (the first 5-7 days).
snipped-for-privacy@gmail.com wrote:
What is your process for making wine? I think that's where we need to begin.
snipped-for-privacy@gmail.com wrote:
Fermentation can stop for a variety of reasons including accidental contamination. However, most stuck fermentations are caused by the following conditions: (1) excessively low or high fermentation temperatures, (2) a lack of available nitrogen, (3) a lack of an essential yeast micro nutrients and (4) excessive quantities of acetic acid.
Fermentation Temperature Undoubtedly, the most common fermentation problem occurs when red fermentations overheat. In warm weather fermentations can become fast and very hot. Then problems often occur because wine yeasts die when fermentation temperatures exceed 90 degrees for just a few hours. This is why contentious winemakers check fermentation temperatures at least once a day. Another kind of temperature problem sometimes occurs when Epernay yeast is used at low fermentation temperatures. Epernay does not tolerate low temperatures very well, and this yeast often stops fermenting when juice is suddenly cooled to below 45 degrees.
Nitrogen Deficiency Diammonium phosphate (DAP) is added to juice and must to provide extra nitrogen, and the nitrogen encourages rapid yeast growth. DAP is usually added to juice or must before fermentation is started, and DAP is a major ingredient in most proprietary yeast foods. California Chardonnay grapes are often deficient in nitrogen, and many winemakers add DAP to all Chardonnay juices to help the yeast ferment completely. Practically all wine yeasts produce excessive amounts of hydrogen sulfide when juice lacks sufficient available nitrogen. Here, winemakers use DAP to provide extra nitrogen to help reduce the quantity of hydrogen sulfide produced.
Micro Nutrients Besides nitrogen, yeasts require several vitamins and amino acids to reproduce the great many yeast cells needed to complete fermentation. Grapes deficient in these materials can be difficult to ferment to dryness unless extra micro nutrients are added to help the yeast. "Super Food," "Startup," "Yeast Extract" and "Yeast Hulls" are commercial preparations used by winemakers to supply micro nutrients.
Excessive Acetic Acid Acetic acid is very toxic to all strains of Saccharomyces (wine) yeast. Yeast activity is curtailed when the acetic acid content of fermenting juice exceeds about 0.1 percent, and fermentation begins to slow. When the acetic acid content exceeds 0.2 to 0.3 percent, few viable yeast cells can be found. Then fermentation stops.
A subtle fermentation problem can develop in the following way. Controlling the native bacteria with sulfur dioxide is difficult when juice pH is high (above 3.8). Under these conditions, a large population of Lactobacillus bacteria sometimes develops early in the primary sugar fermentation. The bacteria convert the grape sugars into acetic acid, and the acetic acid content of the fermentation begins to rise. Little or no ethyl acetate is produced by the Lactobacillus. Acetic acid does not have a strong odor, and without ethyl acetate, the winemaker may not be aware of the problem. Undetected, the lactic bacteria can quickly raise the acetic acid content of the juice into the 0.1 to 0.4 percent range. The wine yeasts are unable to tolerate such high concentrations of acetic acid. The yeast cells begin to die, and the fermentation stops. Then the unhappy winemaker is left with a fermentation both high in volatile acid and high in residual sugar. The high acid content and the high sugar level produce a characteristic sweet-sour taste in the wine.
If you are having trouble with residual sugar year after year, I would switch to Primer Cuvee yeast and provide extra nitrogen and nutrients.
Lum Del Mar, California, USA
You already have good advice from Lum.
I use Lalvin yeasts here and can tell you EC 1118 and K1V1116 like to make dry wines, they are almost idiot proof. I use nutrient too, either DAP, Yeastex or Fermaid, whatever I have on hand or is available.
Joe
One other thing, dry, low acid wines at 11 or 12% or higher tend to taste sweet from the alcohol. If your acids are under 6g/l it may be that.
Joe
Excellent advice! The only thing I can add is to keep the environment stable -- ferment the wine in a location with a constant temperature. A sudden drop in temperature can also stick the fermentation.
For instance, depending upon where you live, your garage may be the worst place possible.
Bryan
Good point. I restarted a stuck Gewurz at about 1% RS with EC1118, I had to warm the wine up for it to get going. I used a heating pad and a few towels. I built up the starter from about a quart to a gallon and then to 6 gallons. It worked well.
When I do sparkling wines I go for 90 PSIG using EC1118 and don't do anything special other than hydrating it first and dumping it in. Granted the wine is lower in alcohol, usually 10 to 11%, but it usually starts up in a day. As soon as I'm sure it's fermenting I stir it up and bottle it. The only time I had an issue was with a mead and it was just an experiment gone terribly wrong.... :)
Joe
Wine spent most of it's life in a heated booth to 69-71F, fairly constant as far as I can tell. Will have to integrate the temperature measurement/logging on the new computer- the old one died due to a lightning strike. I should just put the computer in the booth- why heat both spaces at once?
On a more serious note, I reviewed the logs for when I started the reds. They were all pressed at 1.08 +/- - which means very little body/mouth feel.
Could I add, at this incredibly late date, grape tannin to said wines in order to rescue them from the red-juice wine taste I have now? Am I hoping too much to make a Banrock Station style Cab at 4$/bottle?
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