Yeast hulls are the insoluble cell walls of yeast cells that have been removed from the yeast during the fermentation process. They are a good source of vitamins, minerals, and amino acids, which are essential for yeast growth and metabolism. Yeast hulls can also be used to improve the clarity of wine and beer.
 
Here are some of the benefits of using yeast hulls:
Improved yeast health and fermentation: Yeast hulls can help to improve yeast health and fermentation by providing essential nutrients and by helping to protect the yeast cells from stress.
Reduced astringency and bitterness: Yeast hulls can help to reduce astringency and bitterness in wines and beers by absorbing tannins and other polyphenolic compounds.
Improved clarity: Yeast hulls can help to improve the clarity of wines and beers by adsorbing haze-forming particles.
Increased flavor complexity: Yeast hulls can help to increase the flavor complexity of wines and beers by adding savory and umami flavors.
 
When using yeast hulls, you can add 0.5 to 0.9 grams per gallon of wine or beer. You can add the yeast hulls at the start of fermentation, or during fermentation if the yeast is struggling.
 
If you are using yeast hulls to make a yeast starter, add 1 gram of yeast hulls to 1 liter of water. Stir the yeast hulls into the water until they are completely dissolved. Then, add the yeast to the yeast starter and allow it to ferment for 24-48 hours. Once the yeast starter is fermented, it can be added to the wine or beer.