Ey2d Malolactic Bacteria | Wyeast 4221 | Oenococcus oeni
Wyeast 4221 Ey2d malolactic bacteria for white wines and cool cellars
Wyeast 4221 Ey2d is a fresh liquid Oenococcus oeni malolactic culture for home winemaking. It is used for malolactic fermentation, where malic acid is converted into softer lactic acid to reduce sharp acidity and help the finished wine feel rounder.
Ey2d is the cool-cellar, white-wine choice in Wyeast's home malolactic lineup. Wyeast suggests it for white wines and notes that it was selected for tolerance to low cellar temperatures. That makes it the better pick when you want malolactic conversion but are not holding the wine warm enough for a red-wine-oriented culture.
Best fit
- Recommended use: white wines and wines held at lower cellar temperatures.
- Culture: liquid Oenococcus oeni in a sterile, organic juice-based nutrient medium.
- Temperature range: 55-70°F / 13-21°C.
- Alcohol tolerance: 12-18% ABV.
- Typical conversion time: Wyeast lists malolactic conversion as generally complete within 1-3 months.
- Package size: one home winemaking pouch inoculates 6 gallons / 22 L of must or wine.
How 4221 compares with 4114 and 4007
Choose 4221 Ey2d for white wines and lower cellar temperatures. Choose Wyeast 4114 Er1A when the batch is a red wine or a low-pH wine that benefits from a warmer red-wine strain. Choose Wyeast 4007 Malolactic Blend when you want one broad blend for wine, cider, or mead across a wider temperature and pH range.
| Culture | Best use | Temperature range | Why pick it? |
|---|---|---|---|
| Wyeast 4114 Er1A | Red wines and low-pH conditions | 70-90°F / 21-32°C | Targeted red-wine strain selected for low-pH tolerance. |
| Wyeast 4221 Ey2d | White wines and cooler cellars | 55-70°F / 13-21°C | Suggested by Wyeast for white wines and selected for low cellar temperatures. |
| Wyeast 4007 Blend | Wine, cider, and mead | 55-95°F / 13-35°C | Broad blend for a wider range of temperature and pH conditions. |
How to use Wyeast malolactic cultures
Keep the pouch refrigerated at 34-40°F / 1-4°C and do not freeze it. Before use, let the pouch come to room temperature, sanitize the outside of the package, shake well, then pour into 6 gallons / 22 L of wine, must, or juice that has completed or nearly completed alcoholic fermentation. Wyeast also allows co-inoculation once primary fermentation has begun.
Free SO2, alcohol, pH, temperature, and nutrient status can all affect malolactic fermentation. For the cleanest result, confirm the wine is in a suitable range for the culture and monitor malic acid reduction instead of relying on the calendar alone.
Fresh-culture handling
Liquid malolactic cultures are temperature-sensitive. We store Wyeast cultures cold at SoCal Brewing Supply, and for shipped orders we recommend adding an ice pack to reduce temperature shock during transit.