Diammonium Hydrogen Phosphate (DAP)
Definition - What does Diammonium Hydrogen Phosphate (DAP) mean?
Diammonium hydrogen phosphate, or DAP, is a water-soluble phosphate used in the fermentation process of wine as a nutrient for the yeast. This additive helps the yeast perform better, enabling it to digest sugars more efficiently. It can be added to prevent the formation of hydrogen sulfide or used when hydrogen sulfide is present.
WineFrog explains Diammonium Hydrogen Phosphate (DAP)
During the fermentation process, yeast cells can tire from consuming and converting sugar to alcohol. By adding diammonium hydrogen sulfate (DAP), it can give the yeast a nitrogen boost, thus giving them more energy to continue the fermentation.
It is often recommended to add DAP at certain points during the fermentation when the wine reaches a specific Brix level; 14 to 12 Brix (0.5-0.75 grams/gallon) should be added and also around 9-7-degrees Brix (0.5-0.75 grams/gallon).
This not only gives the yeast a boost, but it can prevent a stuck fermentation. An amount of superfood is often added to the wine simultaneously.