Active Yeast 4

The specific advantages of SIHA Active Yeast 4:

• Secondary fermentation soon starts
• Very good fermentation properties in the cold
• Formation of a fine champagne bouquet with simultaneous intensification of the typical wine aroma
• Easy separation of the yeasts by agitation
• Produces a sparkle with fine bubbles
• Good properties for re-fermentation and fermentation of wines that have stopped fermenting

For rapid start of fermentation and suppression of undesired extraneous organisms, the addition of a high number of living yeast cells is recommended. In the case of champagne, one should operate with an inoculation of approximately 3.7 million cells/fl dr (1 million cells/ml).

In the case of wine that has stopped fermenting, the number of cells must be two to three times higher to achieve rapid completion of the fermentation process. In such wines, yeast multiplication is usually negligible.

The following quantities are given as a guide and should be adapted according to the respective conditions of the wine to be fermented such as health, temperature, presence of residual fungicides, tank size, possibility of temperature control, and regulation.

Wines that have stopped fermenting
Final fermentation of wines that have come to a stop always involves a risk. Frequent and careful inspections of the fermentation process must be carried out.

1. Before re-inoculation of the wine, check whether excessive bacteria have started to develop (formation of volatile acid, excessive development of lactic acid, microscopic control!). Check the degree of fermentation (sugar content) to get an idea of how the fermentation process will continue. If a lot of bacteria have developed, it may be possible to suppress this by means of sulfurization with approximately 0.8 lb SO2 per 1,000 gal (10 g/hl). If the addition of SO2 is not desired or is prevented by legislation, the partly fermented wine should be flush pasteurized at approximately 176 °F (80 °C). Counter pressure during heating will prevent froth formation in the wine. During clarification with normal separators (not fine separators) bacteria are only separated to a small extent. Normal centrifuging is therefore not a substitute for heating or sterile filtration (with filter sheets such as BECO® Steril 40 or BECO Steril 60).
2. Wetting or suspension of the yeast is best done using must at a temperature of 86 °F (30 °C).
3. The fermentation conditions in wines that have stopped prematurely fermenting are very unfavorable (high alcohol content, reduction of yeast nutrients, possible products of bacteria metabolism such as lactic acid or acetic acid, temperature too high or too low). Such unfavorable influences should therefore be compensated as much as possible prior to adding the yeast. The temperature should be between 60 – 77 °F (16 – 25 °C). In the case of bright wines, approximately 0.8 – 1.7 lb (10 – 20 g) cellulose in powder form (BECOCEL™ 150 filter cellulose) should be added per 1,000 gal (per hl) to increase the “inner surface”. If the content of lactic or acetic acid is high, blending with fresh must is recommended. Adding 0.8 – 1.7 lb (10 – 20 g) SIHA Fermentation Salt yeast nutrient fermentation aid per 1,000 gal (per hl) will facilitate yeast growth.
4. It is better to get the yeast accustomed to the fermentation conditions. This is done by first adding the necessary quantity of yeast to a part of the total volume of wine to be fermented (approximately 10%) and allowing it to ferment until about half of the sugar present has been consumed. This start is then added to the remaining 90% of wine. Yeasts that have been adjusted in this way usually ferment faster and are less likely to die than yeasts that are added to the total quantity of wine directly.

Making of Champagne and Sparkling Wine

1. Fermentation in fermenting tank: When making champagnes, sparkling wines, or dessert wines, SIHA Active Yeast 4 can be added directly. To achieve optimum distribution, we recommend the following procedure: Mix the weighed quantity of yeast into approximately 5 to 8 times the amount of water at a temperature of 100 °F (38 °C) in a suitable vessel. This water temperature should be maintained. Continue mixing until there are no lumps in the mixture and then allow to swell for 15 minutes. The yeast will froth up. Then dilute the yeast solution with must or the sugary wine that is to be inoculated, stirring well. This mixture now contains highly active yeast cells and can be used for inoculation immediately or after a short standing time.
2. Fermentation in the bottle: With fermentation in the bottle “Méthode traditionnelle,” it is recommended that the base wines are filtered sterile once more prior to inoculation through filter sheets, e.g., BECO Steril 40 or BECO Steril 60. This prevents a possible decomposition of acid on the bottle. With wines that have passed through a complete acid decomposition stage, this risk is not present. The dry yeast should be reactivated in a wine-water mixture at 86 °F (30 °C) (2.2 lb (1 kg) dry yeast suspended in 5 gal (20 L) of mixture consisting of 4 gal (15 L) wine and 1 gal (5 L) water). Adjust the yeast mixture with “tirage liqueur” to 0.5 – 0.7 lb sugar per gallon (60 – 80 g/L).
3. After a standing time of 3 – 6 hours and a distinct CO2 development, the mixture can be inoculated into the main batch. After inoculation of champagne base wines, the content of free SO2 should not be higher than 0.17 lb/1,000 gal (20 mg/L). If this figure is over 0.21 lb/1,000 gal (25 mg/L), initial fermentation will be delayed by at least 2 – 3 weeks. The toxic effect of the free SO2 is retained until the SO2 has dropped to less than 0.17 lb/1,000 gal (20 mg/L). Adding SIHA Brillant liquid riddling aid and SIHA Tannin liquid fining agent prevents the yeasts from sticking to the surface of the bottle and therefore considerably facilitates the separating (agitating) process.