Yeast was used in fermentation first of all by

Options

A. Hansen
B. Pasteur
C. Spike
D. Jackson

Answer

**Step-by-Step Solution:**

1. **Understanding the Question**: The question asks who was the first to use yeast in fermentation among the given options: Hansen, Pasteur, Spike, or Jackson.

2. **Identifying the Key Figure**: The key figure associated with the use of yeast in fermentation is Louis Pasteur. He is well-known for his contributions to microbiology and fermentation processes.

3. **Pasteur's Contribution**: Pasteur conducted experiments that demonstrated how living yeast cells are responsible for the fermentation process. He showed that yeast converts glucose into ethanol, particularly in the absence of oxygen.

4. **Defining Fermentation**: Fermentation is a metabolic process that converts sugar to acids, gases, or alcohol using microorganisms, such as yeast. Pasteur's work was crucial in understanding this process.

5. **Conclusion**: Based on the evidence and historical context, the correct answer to the question is Louis Pasteur, as he was the first to experimentally demonstrate the role of yeast in fermentation.

**Final Answer**: Yeast was used in fermentation first of all by Louis Pasteur.

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