Let’s tear the wrapper off and dive into the subject of mold on puer tea. I’ve always called puer “The Blue Cheese of Tea”. This is because there is an otherness there. That otherness being 1. Mold, 2. Bacteria, 3. Yeast, and 4. Other Microorganisms. While this list of otherness might sound like cause for concern, this blog post will explore this nuanced subject, in an attempt to inform about the fascinating category of Puer Tea.

Is Mold in Puer Tea Good or Bad?

Well, some are good and some are bad. Certain molds are considered beneficial and enhance the flavor profile of puer tea. Aspergillus genus molds are considered to be good and are typically found in controlled storage environments. However, not all molds are welcome; some can be harmful (mycotoxins). These molds are often a result of improper storage conditions, where humidity and temperature are not adequately controlled.

Optimal Storage Conditions

Humidity: Between 60-70%

Temperature: Between 68-86 degrees Fahrenheit

Ventilation: Proper airflow to prevent stagnant air and mold growth

Light: Keep the tea away from direct sunlight to avoid degradation

How Can We Tell Good Mold From Bad in Puer Tea?

1. Visual

• Good Mold: Beneficial mold, such as Aspergillus spp., usually appears as fine white, yellowish, or light brown spots on the surface of the tea leaves. This mold tends to grow evenly and does not produce a fuzzy texture. It is a sign of controlled fermentation and aging, contributing to the tea's complex flavors.
• Bad Mold: Harmful molds often appear as black, green, blue, or very dark spots. These molds can be fuzzy or powdery and might cover larger areas of the tea leaves. If you see mold with these characteristics, it is best to avoid consuming the tea.

2. Smell

• Good Mold: Tea with beneficial mold will have a rich, earthy aroma, sometimes with a sweet or woody undertone. The smell should be pleasant and inviting, indicating proper aging.
• Bad Mold: Harmful mold emits a musty, mildew-like smell that is sharp and unpleasant. If the tea smells off or moldy in an unpleasant way, it is likely contaminated and should not be consumed.

3. Texture

• Good Mold: Beneficial mold usually integrates smoothly with the tea leaves, forming a fine, almost dust-like coating. The leaves should still feel dry and crisp.
• Bad Mold: Harmful mold often creates a sticky, slimy, or excessively powdery texture. If the tea feels damp or has a noticeable moldy texture, it is likely unsafe to brew.

4. Taste

• Good Mold: Tea with beneficial mold will taste complex, with layers of earthy, sweet, and woody flavors. The taste should be smooth and pleasant, with no sharp or off-putting notes.
• Bad Mold: Harmful mold will impart a sour, bitter, or otherwise unpleasant taste. If the tea tastes moldy or rancid, it is best to stop drinking it immediately.

Ultimately, clean storage conditions will benefit the puer aging process to ensure that mold doesn’t grow unchecked or get out of control. It seems that some puer drinkers have little to no tolerance for mold. This makes sense from the perspective of personal safety. It is important to remember that some molds are not harmful and in fact are beneficial. I hope this article is helpful with regards to making the right choices concerning puer buying.