[Package Content and High Quality] This sourdough starter jar kit contains 1× Sourdough Starter Jar, 1× Wooden Lid, 1× Silicone Spatula, 1× Temperature Paper and 1× Rubber String. Made by high quality glass, wood, cotton linen, silicone, paper, etc. and reusable. The glass sourdough starter jar can withstand temperature up to 150°C.v [Glass Jar Guidelines] Put the sourdough glass jar into the pot with cold water. Boil it for 5 minutes, turn off and cool the glass jar before removing and using. Also, it can be put in the steriliser to disinfect. Please do not put the glass jar in boiled water. Even if the glass jar is heat resistant, it cannot be used in sudden hot and cold situation. Need to preheat the jar first, increase the temperature gradually. [Temperature Paper and Rubber String] This package comes with a temperature paper and rubber string that is convenient for easily reading the temperature of the inside fermenting dough at any time. [Wide Mouth and Spatula] This sourdough starter jar features wide opening that is effortless to clean and convenient add water or flour. And the package comes with jar spatula that can be used for stirring the food stored inside the jar. Also, it can be used for removing the finished fermented fermentation.v [2 Storage Ways] This sourdough starter container is available for 2 storage ways. For refrigerator for a week or more storage, it needs to use the wooden lid for a better sealing and keep food from deteriorating. Can be used for storing canned food, dried fruits, mixed grains, caviar, pickles keeping fresh. For fermentation use, use a breathable cloth cover with a strong elastic band allowing the air to flow in and out. Suitable for a natural yeast fermentation.