A fermentation vessel is a container used to hold and manage the fermentation process, where microorganisms like yeast or bacteria convert sugars into alcohol, gases, or acids. These vessels can be made from various materials, including glass, plastic, or stainless steel, and come in different shapes and sizes depending on the type of fermentation being conducted. Fermentation vessels are essential in producing a variety of products, such as beer, wine, and yogurt. They are designed to create a controlled environment, allowing for optimal temperature and pressure, while also preventing contamination from unwanted microorganisms.