Hygiene compliance is essential while preparing kefir (water kefir, milk kefir) and komubucha beverages; therefore, it is very important to always pay attention to hygiene when it comes to kombucha.
If you notice any unusual odors and/or colors, blisters or if mold appears on your kombucha strains, you must not drink the beverage obtained. A more or less strong vinegar smell, depending on the fermentation time, is quite normal.
Always use utensils easy to maintain (glass jar, fine mesh plastic strainer).
To wash utensils, there is no need to sterilize them; by cons, always use hot water and dish detergent preferably made of natural products, and take care not to burn yourself when doing this.
For the jar, you can use glass jars for vegetables for e.g., that you can easily find on the market. You must carefully clean the jar before use, as described here.
Mesh plastic strainers and plastic little spoons being affordable, the best is to buy them new and used them only for your probiotic cultures.
Once utensils cleaned as described, you have to let them cool completely, as kombucha strainers can’t withstand high temperatures. Only after that you can start a new culture.