Most common causes (of stuck ferments):
- Mistake in re-hydration process
- High brix must = high alcohol
- Temperature spikes (heat and cold)
- Toxins produced from struggling yeast
- Competition from mold
- Nutrient Deficiency
The first step is to know what your numbers are. Send a sample to ETS or My Enologist for brix/RS, VA, Malic, Ethanol, Free/Total SO2, pH and TA. If your VA number is high, it is a good idea to request a Scorpions Stuck and Sluggish Fermentation Panel at ETS. This way, you will see what/who is causing the problem. Knowing what kind of microbe is causing problems will determine whether Lysozyme is needed or not. If your VA number is really high, you will need to lower the VA before starting with your yeast re-start, as VA inhibits yeast activity.
I am happy to work with you to determine the best way to treat the stuck ferment. Once you have your numbers, give me a call or send me an e-mail. In general, follow the basic steps of 1) detoxify your medium (rack off lees, add Bioactive), 2) rehydrate with Actiflore BO213 and Dynastart, 3) slowly acclimate the yeast culture to the stuck wine. Attached is a more detailed step by step restart protocol.
Products and Rates
Bioactive: a blend of yeast hulls for detoxification, cellulose for support in keeping yeast in suspension, and non-nitrogenous yeast nutrition to boost the yeast. 300-400ppm
Dynastart: yeast derived re-hydration nutrient rich in sterols, vitamins, minerals and fatty acids. Dynastart will protect your yeast and make them more resistant to the challenging conditions of a stuck ferment. 300ppm
BO213 Yeast: Bayanus strain that is specifically recommended for restarting stuck ferments. Fructophilic, tolerant to 18% alcohol, low VA production, and short lag phase. 400-500ppm
Yeast Restart Protocol