Why am I not sealing shut the lid of my primary fermenter in the primary fermentation?
Many winemakers do not have an airlock on the primary fermenter because technically this is not necessary. If you already have an airlock and bung on your lid, please ignore the direction of not sealing the lid of your primary fermenter.
Yeasts need oxygen to live, to multiply and to turn sugar into alcohol. The must in fermentation releases a lot of CO2 gas during the primary fermentation. Yeasts, if they are ”submerged” by too much CO2, will not be able to complete their mission and finish the fermentation. In addition, the lid helps prevent external contamination in your must. Additionally, it makes it simpler to stir the must daily without having to remove the cover. However, if you have an airlock and prefer to continue doing it your way, that is fine too.