Don’t Get Stuck With a “Stuck Fermentation”

 

By Eric R. Mentzer

 

It could be your worst nightmare! You’ve picked up some excellent quality juice with a high Brix value from a vineyard, hoping to turn it into your own homemade wine. You did what you thought was right, including adding a bit of sulfite to the juice to ward off unwanted bacteria and wild yeast. You let that do its thing, and then you sprinkled yeast you got from the local wine supply store on the juice.

 

Within a day of sprinkling the yeast, there were signs of fermentation and you were looking forward to when you could bottle your wine, let it age awhile, and then proudly serve it to guests. But today, the fermentation has become sluggish, or all but stopped. And, you know from the specific gravity reading that you took that there is still lots of sugar left to be consumed by the yeast.

 

You’ve got a stuck fermentation. What happened?  What went wrong? Is there anything you can do about it? Let’s answer the “what went wrong” with some possibilities first:

 

1. You used unsanitary equipment from the start. Always, always ensure your equipment is sanitized with a sanitizing solution.

 

2. The yeast you picked up was beyond its expiration date. If not properly stored and used within its shelf life, it can weaken and might not grow and reproduce.

 

3. The yeast you used could not tolerate the alcohol levels it had produced in your wine. Some yeast are not as tolerant of alcohol as others, and perhaps you used a yeast that had a lower alcohol tolerance.

 

4. The temperature was not ideal for the strain of yeast you were using. Different strains of yeast have different temperature ranges that they can work in efficiently. If the temperature gets too warm, yeast will die. If the temperature gets too low, they go dormant.

 

5. There wasn’t enough oxygen in the juice. You’ll hear and read over and over that air is the worst enemy in winemaking, however this is after the fermentation has gotten under way. Yeast do need oxygen and you can help by giving the contents of your pail a good stirring at least once a day for the first few days.

 

Now that we’ve covered some of the possibilities as to why you have a stuck fermentation, you should be able to figure out what you can do to prevent one in the future.

 

But if you’ve got a stuck fermentation now, or ever do have one in the future, there is a way to have hope. If you have a “stuck fermentation” right now, hopefully you have a winemaking supply store within a short distance which likely carries EC-1118 strain of yeast. Get a packet of that and re-inoculate your pail of wine with it.

 

EC-1118 yeast is used by winemakers all over the world for making some very good wines and due to it’s tolerance to a wide range of temperature as well as a tolerance to alcohol up to 18%, it is the “go-to” yeast for stuck fermentations. It also helps that it has a mostly neutral effect on taste and aroma of the final wine.

 

If you plan on making a lot of wine, keeping a few spare packets of EC-1118 yeast in the freezer is a very wise thing to do.

 

Try these tips if you have stuck fermentation and let me know how it came out.