What Is The Differences between Molds and Yeasts(With Table)

So, what is the difference between molds and yeasts? The former is a multicellular filament of fungi whereas the latter is a unicellular type of fungi. Besides that, molds reproduce by either asexual or sexual and yeasts by budding. 

Both Yeasts and molds belong to the kingdom fungi. Organisms in the fungi kingdom are either unicellular or multicellular eukaryotes.  These organisms survive as saprophytes by decomposing organic matter and absorbing nutrients from their cell walls. These living things are visible to the naked eyes under a colony. 

Keep in mind that all organisms that belong to kingdom fungi are eukaryotes. These organisms have cell nuclei and membrane-bound organelles.  This article provides a comprehensive insight into the differences between molds and yeasts. Remember to find out more about the similarities and other hidden gems about these organisms. 

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Differences between Molds and Yeasts(With Table)

Basic Terms




These are multicellular microorganisms that belong to the fungi kingdom.

These are unicellular microorganisms that belong to the fungi kingdom.

Type of Cell




Grow as multiple tubular branches.

Grows as large single cells.


Dark, damp, and humid areas.

Found on fruits, inside mammals’ stomachs, and on the skin.


Fuzzy appearance

White and thread-like.


Have microscopic filaments in form of hyphae.

Do not have true hyphae.


It is a sporing fungus.

Not a sporing fungus.


Have vibrant colors

Less vibrant in colors.

Incubation Period

Occurs when the temperature range between 25oC and 30oC.

When the temperature ranges from 20oC to 30oC.

Cultivation Duration

The growth rate is quite slow.

Grow within 26 to 36 hours.

Aerobic or Anaerobic

Aerobic condition.

Both aerobic and anaerobic conditions.

pH Range

Thrive mostly in acidity.

pH should range from 4.0 to 4.5


Through microscopic examination.

Physiological tests.


Either asexual or sexual


Asexual Spores

Sporangiospore and conidia.


Sexual Spores

Zygospores, Ascospores, and Basidiospores

No sexual spores.

Energy Production

Secrete hydrolytic enzymes that degrade biopolymers into simpler substances that can be absorbed.

Convert carbohydrates to alcohol and carbon dioxide in anaerobic through fermentation.

Health Risk

Results in allergic reactions and respiratory problems.

Compromise the immune system of a person.

Other Issues

Cause food spoilage and sanitation problems.

Results in fewer food spoilage issues.


Food processing and decomposition of organic materials.

Vitamin supplements, baking, and ethanol production.

Number of Species




No specific shape

Oval shape


Alternaria, Aspergillus, Fusarium, Mucor, Penicillium, etc

Saccharomyces cerevisiae, Cryptococcus neoformans, etc.

What Are Molds?

Molds are a type of fungus that belongs to the kingdom Fungi. They are a diverse group of microorganisms that play essential roles in the natural environment by decomposing organic matter. Molds are characterized by their filamentous structures called hyphae, which collectively form a network known as mycelium. The mycelium allows molds to grow and spread across surfaces, enabling them to absorb nutrients from their surroundings.

Molds reproduce through the formation of spores, which are small, lightweight structures capable of being dispersed through the air, water, or other carriers. These spores serve as the means by which molds colonize new areas and establish themselves in different environments.

While molds are ecologically important for breaking down dead organic matter and recycling nutrients, they can also be problematic in indoor environments. In buildings, molds can thrive in damp or humid conditions and may grow on various surfaces, including walls, ceilings, and household items. Indoor mold growth can lead to health concerns, as certain molds produce allergens, irritants, or mycotoxins that can cause respiratory issues or allergic reactions in some individuals.

In addition to their environmental impact, molds have been used in various beneficial ways by humans. Certain molds, such as those from the genus Penicillium, have been crucial in the production of antibiotics like penicillin. Molds are also employed in the fermentation processes for the production of foods like cheese, soy sauce, and certain types of bread.

In summary, molds are fungi characterized by hyphal structures, mycelium, and spore reproduction. While they play important roles in nature, breaking down organic matter, some molds can pose challenges when they proliferate in indoor environments, affecting air quality and potentially causing health issues.

What Is Yeast?

Yeast is a type of fungus belonging to the kingdom Fungi. Unlike molds, which typically form multicellular structures with visible mycelium, yeast consists of single-celled organisms. The most well-known yeast species is Saccharomyces cerevisiae, widely used in various industrial and culinary applications.

One of the most notable roles of yeast is in fermentation. Yeast can metabolize sugars to produce alcohol and carbon dioxide through a process known as alcoholic fermentation. This property is extensively utilized in the production of alcoholic beverages like beer and wine, as well as in the leavening of bread. In bread-making, yeast ferments sugars in the dough, producing carbon dioxide gas, which causes the dough to rise and results in a light and fluffy texture in the finished bread.

Aside from its role in fermentation, yeast is a valuable organism in scientific research. The species Saccharomyces cerevisiae, in particular, has been extensively studied and is considered a model organism. Its simple and well-understood genetics make it an excellent subject for genetic and molecular biology experiments.

In the field of biotechnology, yeast is used for the production of various products, including biofuels, enzymes, and pharmaceuticals. The ability of yeast to efficiently convert sugars into ethanol has led to its use in biofuel production.

Yeast cells are also commonly used in the laboratory to study fundamental cellular processes. Their small size, rapid growth, and genetic tractability make them valuable tools for researchers studying topics such as cell division, DNA replication, and gene expression.

In summary, yeast is a single-celled fungus with a significant impact on both industry and research. Its ability to ferment sugars and produce carbon dioxide and alcohol is harnessed in the production of food and beverages, while its genetic and cellular simplicity makes it a valuable organism for scientific study and biotechnological applications.

Main Differences Between Molds and Yeast

  1. Molds are multicellular microorganisms while yeast is a single-cell microorganism. Both belong to the fungi kingdom.
  2. There are about 400,000 types of molds in a dark and damp area while 1500 types of yeast on fruits, vegetables, and mammal skin.
  3. Molds are colorfully marked with filamentous hyphae while yeast is colorless and smooth. Yeast tends to have pseudo-filamentous structures.
  4. Yeast is commercially used to make foods and beverages such as alcohol while molds for making antibiotic drugs.
  5. Molds cause allergic reactions and other respiratory problems while yeast causes infections that compromise the immunity of an individual.
  6. Examples of molds are Mucor, Penicillium, Rhizopus, and Aspergillus while examples of yeast are Baking yeast and Cryptococcus neoformans.
  7. Molds reproduce both sexually and asexually while yeast reproduces through binary fission or budding method.
  8. Molds are found in damp and dark areas whereas yeast is found on fruits, mammal skin, and inside the stomach.
  9. Molds are thread-like while yeasts have an oval shape 
  10. Molds have a fuzzy appearance while yeast have the white and thready appearance
  11. Molds have microscopic filaments whereas yeasts have no hyphae
  12. Mold is a sporing fungus while yeast is not a sporing fungi
  13. Yeast converts carbohydrates to alcohol during fermentation whereas molds secrete hydrolytic enzymes to external food sources and absorb nutrients.
  14. There are about 400,000 types of molds whereas 1500 types of yeasts.
  15. Molds are more virulent whereas yeasts are less virulent

Similarities Between Molds and Yeasts

  1. Both are types of fungi
  2. Both have chitin and glucose derivatives
  3. Both can decompose porous households
  4. Both undergo chemical reaction during germination
  5. Both require moisture for germination 
  6. Both are vulnerable to heat 
  7. Both require oxygen to grow
  8. Both causes allergic reaction 
  9. Both are eukaryotes
  10. Both have health hazards 
  11. Both are sporophytes 

Frequently Asked Questions

  • How Can You Kill Mold and Yeast?

Getting rid of molds and yeast is quite easy. Both yeast and molds are quite sensitive to heat. Therefore, exposing them to high heat will kill them automatically. Ensure the temperature is between 140-160°F. 

  • What Are the Growth Conditions for Mold and Yeast?

Molds grow in moist and dark areas while yeast can grow in any environment. 

  • Is Mold a Bacteria or Virus?

Virus. Mold produces viral allergens that cause respiratory health problems. But mold belongs to the Fungi Kingdom and bacteria are not. 

  • Does Mold Cause Viruses?

Yes. Mold produces bacteria and viruses that cause cold or food-borne diseases. Most of the allergens produced by molds cause respiratory problems. 

  • Which Kingdom Do Mold and Yeast Belong?

Molds and Yeast belong to the Fungi Kingdom

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Molds and yeasts are both types of fungi, but they exhibit distinct characteristics and lifestyles. Molds are multicellular fungi characterized by filamentous structures called hyphae, forming a mycelium. They reproduce through spores and play a crucial role in decomposing organic matter in the environment. While molds can be beneficial for recycling nutrients in nature, certain species can be problematic indoors, causing health concerns.

On the other hand, yeasts are unicellular fungi, consisting of individual yeast cells. The well-known species Saccharomyces cerevisiae is widely utilized in various applications, particularly in fermentation processes. Yeasts play a key role in the production of alcoholic beverages like beer and wine, as well as in leavening bread. Their ability to metabolize sugars into alcohol and carbon dioxide distinguishes them from molds.

In terms of lifestyle, molds typically form visible colonies on surfaces, whereas yeasts are often dispersed as single cells. Molds thrive in humid conditions and can grow on a variety of surfaces, causing issues in indoor environments. In contrast, yeasts are versatile and can adapt to diverse environments, playing important roles in both industrial processes and scientific research.

While molds and yeasts share the common classification of fungi, their structural and reproductive differences, as well as their distinct roles in various applications, set them apart in the biological and practical contexts. Molds are associated with mycelial growth and spore formation, while yeasts are characterized by unicellular structures and are prominently utilized in fermentation and biotechnological processes.

More Sources and References

  1. Introduction to Mycology. NCBI

  2. Do Mold Spores Cause Lung Cancer? Havard Health Publishing

  3. Black Mold Spores and More. Healthline 

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