# Contested concept: fermentation

_**What you are reading**: one contested-concept page in Deliberus's deliberation graph. Deliberus maps human reasoning — including claims that are contested, mistaken, or extreme — so that disagreement can be examined precisely. A claim's presence here is not an endorsement: the graph records that someone argued it, how it connects to other reasoning, and how far scrutiny has gotten. The metadata on this page describes the state of that scrutiny, not the truth of the claim._

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- **Contestedness**: semantic
- **Diagnosis**: The disagreement is partly historical and partly about scope. Whether fermentation is defined by metabolic mechanism, by biological agency, or by manufacturing context determines which processes count. The definition is also stretched to cover products like heme proteins that fall outside the biochemical sense.
- **Canonical**: `/concept/fermentation` (data: `/concept/fermentation.json`)

## Senses in use
- **Biochemical: catabolism with organic compounds as both electron donor and acceptor, distinct from respiration (with caveats for H2 donors and CO2 acceptors)** — used in 8 claim(s)
- **Industrial/loose: a large-scale biological manufacturing process, or any chemical modification by a living being in a controlled container, including non-biochemical cases such as alternative proteins and enzymes** — used in 8 claim(s)
- **Enzyme-catalyzed process that does not require living cells** — used in 5 claim(s)
- **Pasteur's 'life without air', a process initiated by living organisms** — used in 3 claim(s)
- **Simple chemical reaction with no organisms involved** — used in 3 claim(s)

## Claims using this term
- [Success came in 1897 when the German chemist Eduard Buechner ground up yeast, extracted a juice from [the yeast]](/claim/claim_034aa2fb8fed.md) _(sense: Enzyme-catalyzed process that does not require living cells)_
- [Louis Pasteur showed fermentation is initiated by living organisms in a series of investigations.](/claim/claim_04f1bcb5c499.md) _(sense: Pasteur's 'life without air', a process initiated by living organisms)_
- [In food and industrial contexts, any chemical modification performed by a living being in a controlled container can be termed "fermentatio…](/claim/claim_218e51356f13.md) _(sense: Industrial/loose: a large-scale biological manufacturing process, or any chemical modification by a living being in a controlled container, including non-biochemical cases such as alternative proteins and enzymes)_
- [The myoglobin and leghemoglobin ingredients [used in meat analogues] come from a vat instead of meat.](/claim/claim_33ac98669b95.md) _(sense: Industrial/loose: a large-scale biological manufacturing process, or any chemical modification by a living being in a controlled container, including non-biochemical cases such as alternative proteins and enzymes)_
- [Thus, it is simplest to use the definition of fermentation as "catabolism where organic compounds are both the electron donor and acceptor"…](/claim/claim_35e439b21cd9.md) _(sense: Biochemical: catabolism with organic compounds as both electron donor and acceptor, distinct from respiration (with caveats for H2 donors and CO2 acceptors))_
- [Solid-state fermentation adds a small amount of water to a solid substrate](/claim/claim_3f411fd3db40.md) _(sense: Industrial/loose: a large-scale biological manufacturing process, or any chemical modification by a living being in a controlled container, including non-biochemical cases such as alternative proteins and enzymes)_
- [From that time on [after Eduard Buechner's 1897 results], the term enzyme came to be applied to all ferments.](/claim/claim_665eeb77caa3.md) _(sense: Enzyme-catalyzed process that does not require living cells)_
- [Industrial fermentation is another type of fermentation [besides the biochemical definitions of fermentation discussed]](/claim/claim_678adf43ec58.md) _(sense: Industrial/loose: a large-scale biological manufacturing process, or any chemical modification by a living being in a controlled container, including non-biochemical cases such as alternative proteins and enzymes)_
- [The simplest and most recent definition of fermentation proposed is "catabolism where organic compounds are both the electron donor and acc…](/claim/claim_7262d15ada7f.md) _(sense: Biochemical: catabolism with organic compounds as both electron donor and acceptor, distinct from respiration (with caveats for H2 donors and CO2 acceptors))_
- [Solid-state fermentation is widely used in the food industry to produce flavors, enzymes and organic acids.](/claim/claim_769c2f4bb81c.md) _(sense: Industrial/loose: a large-scale biological manufacturing process, or any chemical modification by a living being in a controlled container, including non-biochemical cases such as alternative proteins and enzymes)_
- [The 'father of modern chemistry', Antoine Lavoisier, had viewed fermentation as a simple chemical reaction](/claim/claim_7b505acbcba3.md) _(sense: Simple chemical reaction with no organisms involved)_
- [It was then [after Eduard Buechner's results and the application of the term enzyme to all ferments] understood fermentation is caused by e…](/claim/claim_7da575b8de03.md) _(sense: Enzyme-catalyzed process that does not require living cells)_
- [The definition of industrial fermentation as a large-scale biological manufacturing process focuses on the process of manufacturing rather …](/claim/claim_7df28dcb1554.md) _(sense: Industrial/loose: a large-scale biological manufacturing process, or any chemical modification by a living being in a controlled container, including non-biochemical cases such as alternative proteins and enzymes)_
- [By the 19th century, [the view that fermentation is a simple chemical reaction and that living organisms are not involved] was seen as vita…](/claim/claim_86c2edf9fe32.md) _(sense: Simple chemical reaction with no organisms involved)_
- [Pasteur's definition of fermentation as "Life without air" was incorrect because the discovery that living microorganisms cause fermentatio…](/claim/claim_8b04dd7b0c75.md) _(sense: Pasteur's 'life without air', a process initiated by living organisms)_
- [The definition of fermentation as "catabolism where organic compounds are both the electron donor and acceptor" distinguishes fermentation …](/claim/claim_8cc288a8c354.md) _(sense: Biochemical: catabolism with organic compounds as both electron donor and acceptor, distinct from respiration (with caveats for H2 donors and CO2 acceptors))_
- [Fermentation produces between 2 and 5 ATP molecules per glucose.](/claim/claim_8cd05ae82ee1.md) _(sense: Biochemical: catabolism with organic compounds as both electron donor and acceptor, distinct from respiration (with caveats for H2 donors and CO2 acceptors))_
- [this "dead" liquid [the juice extracted from ground up yeast] would ferment a sugar solution, forming carbon dioxide and alcohol much like …](/claim/claim_8e7f58024767.md) _(sense: Enzyme-catalyzed process that does not require living cells)_
- [The following [alternative protein production and enzyme production] do not fall into the biochemical sense [of fermentation], but are call…](/claim/claim_9e1229d1d284.md) _(sense: Industrial/loose: a large-scale biological manufacturing process, or any chemical modification by a living being in a controlled container, including non-biochemical cases such as alternative proteins and enzymes)_
- [[Louis Pasteur] defined fermentation (incorrectly) as "Life without air".](/claim/claim_bc902e85c8fe.md) _(sense: Pasteur's 'life without air', a process initiated by living organisms)_
- [However, the definition of fermentation as "catabolism where organic compounds are both the electron donor and acceptor" does not encompass…](/claim/claim_c44e6384b8b5.md) _(sense: Biochemical: catabolism with organic compounds as both electron donor and acceptor, distinct from respiration (with caveats for H2 donors and CO2 acceptors))_
- [Antoine Lavoisier rejected the notion that living organisms could be involved [in fermentation]](/claim/claim_c9d812c6e2e1.md) _(sense: Simple chemical reaction with no organisms involved)_
- [Fermentation does not need an exogenous electron acceptor.](/claim/claim_ca2dc48517c6.md) _(sense: Biochemical: catabolism with organic compounds as both electron donor and acceptor, distinct from respiration (with caveats for H2 donors and CO2 acceptors))_
- [In the second step of butyrate fermentation CO2 can act as an electron acceptor, which the definition of fermentation as "catabolism where …](/claim/claim_d3c753696c4a.md) _(sense: Biochemical: catabolism with organic compounds as both electron donor and acceptor, distinct from respiration (with caveats for H2 donors and CO2 acceptors))_
- [Industrial fermentation is defined loosely as a large-scale biological manufacturing process](/claim/claim_ebc781b8d03f.md) _(sense: Industrial/loose: a large-scale biological manufacturing process, or any chemical modification by a living being in a controlled container, including non-biochemical cases such as alternative proteins and enzymes)_
- [The "unorganized ferments" [ferments in the extract from ground up yeast] behaved just like the organized ones [ferments in living yeast].](/claim/claim_ed6648dd5b93.md) _(sense: Enzyme-catalyzed process that does not require living cells)_
- [Propionate fermentation uses H2 as an electron donor, which the definition of fermentation as "catabolism where organic compounds are both …](/claim/claim_fb0f7bd71ffc.md) _(sense: Biochemical: catabolism with organic compounds as both electron donor and acceptor, distinct from respiration (with caveats for H2 donors and CO2 acceptors))_