Acetic acid - Revision history

Matthew: /* In Lambic */

2025-03-21T15:08:47Z

In Lambic

← Older revision		Revision as of 15:08, 21 March 2025
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	==In Lambic==		==In Lambic==
	The synthesis of acetic acid can occur through direct oxidation of ethanol, though this process is very slow in anaerobic conditions [ref]. Some bacteria, notably Acetomonas and Acetobacter can catalyze the conversion of ethanol to acetic acid, greatly speeding up the process. The former can continue the oxidation process to fully convert ethanol to carbon dioxide and water, but the latter species is incapable of progressing beyond acetic acid. Both of these bacteria require oxygen for the reaction to take place, so the production of acetic acid occurs early in the fermentation process, when the wort is still well-oxygenated. After about 6 weeks, the production of acetic acid trails off and the concentration will remain the same until the end of fermentation <ref name=Oevelen77 >D. Van Oevelen, M. Spaepen, P. Timmermans and H. Verachtert, [http://onlinelibrary.wiley.com/doi/10.1002/j.2050-0416.1977.tb03825.x/abstract\|MICROBIOLOGICAL ASPECTS OF SPONTANEOUS WORT FERMENTATION IN THE PRODUCTION OF LAMBIC AND GUEUZE], 1977</ref>. As acetic acid bacteria are ever-present in the wort, exposure to excessive oxygen at any time during fermentation will lead to the formation of large amounts of acetic acid, sometimes up to 4 g/l <ref name=Oevelen77 >D. Van Oevelen, M. Spaepen, P. Timmermans and H. Verachtert, [http://onlinelibrary.wiley.com/doi/10.1002/j.2050-0416.1977.tb03825.x/abstract\|MICROBIOLOGICAL ASPECTS OF SPONTANEOUS WORT FERMENTATION IN THE PRODUCTION OF LAMBIC AND GUEUZE], 1977</ref>, at which point the lambic is referred to as "hard", though it is still useful for blending <ref name=Guinard >Jean-Xavier Guinard , [[Books#Classic_Beer_Styles:_Lambic\|Classic Beer Styles: Lambic]], 1990</ref>.		The synthesis of acetic acid can occur through direct oxidation of ethanol, though this process is very slow in anaerobic conditions [ref]. Some bacteria, notably Acetomonas and Acetobacter can catalyze the conversion of ethanol to acetic acid, greatly speeding up the process. The former can continue the oxidation process to fully convert ethanol to carbon dioxide and water, but the latter species is incapable of progressing beyond acetic acid. Both of these bacteria require oxygen for the reaction to take place, so the production of acetic acid occurs early in the fermentation process, when the wort is still well-oxygenated. After about 6 weeks, the production of acetic acid trails off and the concentration will remain the same until the end of fermentation <ref name=Oevelen77 >D. Van Oevelen, M. Spaepen, P. Timmermans and H. Verachtert, [http://onlinelibrary.wiley.com/doi/10.1002/j.2050-0416.1977.tb03825.x/abstract\|MICROBIOLOGICAL ASPECTS OF SPONTANEOUS WORT FERMENTATION IN THE PRODUCTION OF LAMBIC AND GUEUZE], 1977</ref>. As acetic acid bacteria are ever-present in the wort, exposure to excessive oxygen at any time during fermentation will lead to the formation of large amounts of acetic acid, sometimes up to 4 g/L <ref name=Oevelen77 >D. Van Oevelen, M. Spaepen, P. Timmermans and H. Verachtert, [http://onlinelibrary.wiley.com/doi/10.1002/j.2050-0416.1977.tb03825.x/abstract\|MICROBIOLOGICAL ASPECTS OF SPONTANEOUS WORT FERMENTATION IN THE PRODUCTION OF LAMBIC AND GUEUZE], 1977</ref>, at which point the lambic is referred to as "hard", though it is still useful for blending <ref name=Guinard >Jean-Xavier Guinard , [[Books#Classic_Beer_Styles:_Lambic\|Classic Beer Styles: Lambic]], 1990</ref>.

	==As a precursor to other molecules in Lambic==		==As a precursor to other molecules in Lambic==

Matthew: /* Chemical and physical properties */

2025-03-21T15:04:20Z

Chemical and physical properties

← Older revision		Revision as of 15:04, 21 March 2025
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	==Chemical and physical properties==		==Chemical and physical properties==
	Acetic acid is a low molecular-weight organic acid, with a lower acidity than lactic acid. It is the acid conjugate to ethanol and is often formed by the oxidation thereof. Along with water, it is the primary component in vinegar, and thus its flavor and odor are characteristic of vinegar. As a pure liquid, it has a boiling point of ~~~120~~ C and a vapor pressure at room temperature around 1000 Pa, indicating moderate volatility.		Acetic acid is a low molecular-weight organic acid, with a lower acidity than lactic acid. It is the acid conjugate to ethanol and is often formed by the oxidation thereof. Along with water, it is the primary component in vinegar, and thus its flavor and odor are characteristic of vinegar. As a pure liquid, it has a boiling point of ~120º C and a vapor pressure at room temperature around 1000 Pa, indicating moderate volatility.

	==In Lambic==		==In Lambic==

Matthew: /* As a precursor to other molecules in Lambic */

2025-03-21T14:49:25Z

As a precursor to other molecules in Lambic

← Older revision		Revision as of 14:49, 21 March 2025
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	Acetic acid can combine with ethanol to form the ester ethyl acetate, via the reaction:		Acetic acid can combine with ethanol to form the ester ethyl acetate, via the reaction:

	~~CH3COOH~~ + ~~CH3CH2OH~~ -> ~~CH3COOCH2CH3~~ + ~~H2O~~		CH₃COOH + CH₃CH₂OH -> CH₃COOCH₂CH₃ + H₂O

	Ethyl acetate has a green-apple ~~like scent~~ in the concentrations that are likely to be found in lambic.		Ethyl acetate has a scent reminiscent of green apple in the concentrations that are likely to be found in lambic.

	==References==		==References==

	<references />		<references />

Matt at 15:14, 8 June 2020

2020-06-08T15:14:47Z

← Older revision		Revision as of 15:14, 8 June 2020
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	==Chemical and physical properties==		==Chemical and physical properties==
	Acetic acid is a low molecular-weight organic acid, with a lower acidity than lactic acid. It is the acid conjugate to ethanol and is often formed by the oxidation ~~therof~~. Along with water, it is the primary component in vinegar, and thus its flavor and odor are characteristic of vinegar. As a pure liquid, it has a boiling point of ~120 C and a vapor pressure at room temperature around 1000 Pa, indicating moderate volatility.		Acetic acid is a low molecular-weight organic acid, with a lower acidity than lactic acid. It is the acid conjugate to ethanol and is often formed by the oxidation thereof. Along with water, it is the primary component in vinegar, and thus its flavor and odor are characteristic of vinegar. As a pure liquid, it has a boiling point of ~120 C and a vapor pressure at room temperature around 1000 Pa, indicating moderate volatility.

	==In Lambic==		==In Lambic==
	The synthesis of acetic acid can occur through direct oxidation of ethanol, though this process is very slow in anaerobic conditions [ref]. Some bacteria, ~~noteably~~ Acetomonas and Acetobacter can catalyze the conversion of ethanol to acetic acid, greatly speeding up the process. The former can continue the oxidation process to fully convert ethanol to carbon dioxide and water, but the latter species is incapable of progressing beyond acetic acid. Both of these bacteria require oxygen for the reaction to take place, so the production of acetic acid occurs early in the fermentation process, when the wort is still well-oxygenated. After about 6 weeks, the production of acetic acid trails off and the concentration will remain the same until the end of fermentation <ref name=Oevelen77 >D. Van Oevelen, M. Spaepen, P. Timmermans and H. Verachtert, [http://onlinelibrary.wiley.com/doi/10.1002/j.2050-0416.1977.tb03825.x/abstract\|MICROBIOLOGICAL ASPECTS OF SPONTANEOUS WORT FERMENTATION IN THE PRODUCTION OF LAMBIC AND GUEUZE], 1977</ref>. As acetic acid bacteria are ever-present in the wort, exposure to excessive oxygen at any time during fermentation will lead to the formation of large amounts of acetic acid, sometimes up to 4 g/l <ref name=Oevelen77 >D. Van Oevelen, M. Spaepen, P. Timmermans and H. Verachtert, [http://onlinelibrary.wiley.com/doi/10.1002/j.2050-0416.1977.tb03825.x/abstract\|MICROBIOLOGICAL ASPECTS OF SPONTANEOUS WORT FERMENTATION IN THE PRODUCTION OF LAMBIC AND GUEUZE], 1977</ref>, at which point the lambic is referred to as "hard", though it is still useful for blending <ref name=Guinard >Jean-Xavier Guinard , [[Books#Classic_Beer_Styles:_Lambic\|Classic Beer Styles: Lambic]], 1990</ref>.		The synthesis of acetic acid can occur through direct oxidation of ethanol, though this process is very slow in anaerobic conditions [ref]. Some bacteria, notably Acetomonas and Acetobacter can catalyze the conversion of ethanol to acetic acid, greatly speeding up the process. The former can continue the oxidation process to fully convert ethanol to carbon dioxide and water, but the latter species is incapable of progressing beyond acetic acid. Both of these bacteria require oxygen for the reaction to take place, so the production of acetic acid occurs early in the fermentation process, when the wort is still well-oxygenated. After about 6 weeks, the production of acetic acid trails off and the concentration will remain the same until the end of fermentation <ref name=Oevelen77 >D. Van Oevelen, M. Spaepen, P. Timmermans and H. Verachtert, [http://onlinelibrary.wiley.com/doi/10.1002/j.2050-0416.1977.tb03825.x/abstract\|MICROBIOLOGICAL ASPECTS OF SPONTANEOUS WORT FERMENTATION IN THE PRODUCTION OF LAMBIC AND GUEUZE], 1977</ref>. As acetic acid bacteria are ever-present in the wort, exposure to excessive oxygen at any time during fermentation will lead to the formation of large amounts of acetic acid, sometimes up to 4 g/l <ref name=Oevelen77 >D. Van Oevelen, M. Spaepen, P. Timmermans and H. Verachtert, [http://onlinelibrary.wiley.com/doi/10.1002/j.2050-0416.1977.tb03825.x/abstract\|MICROBIOLOGICAL ASPECTS OF SPONTANEOUS WORT FERMENTATION IN THE PRODUCTION OF LAMBIC AND GUEUZE], 1977</ref>, at which point the lambic is referred to as "hard", though it is still useful for blending <ref name=Guinard >Jean-Xavier Guinard , [[Books#Classic_Beer_Styles:_Lambic\|Classic Beer Styles: Lambic]], 1990</ref>.

	==As a precursor to other molecules in Lambic==		==As a precursor to other molecules in Lambic==

Matt: added return link

2020-06-08T15:13:22Z

added return link

← Older revision		Revision as of 15:13, 8 June 2020
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			[[Microbiology_and_Biochemistry\|← Microbiology and Biochemistry]]


	Acetic acid is an organic compound formed in lambic by the oxidation of ethanol. An organic acid, it is a colorless liquid in its pure state with a strong acidic odor. In more dilute solution, the odor can take on a smell of overripe fruit. Acetic acid is best known as the primary flavor component of vinegar.		Acetic acid is an organic compound formed in lambic by the oxidation of ethanol. An organic acid, it is a colorless liquid in its pure state with a strong acidic odor. In more dilute solution, the odor can take on a smell of overripe fruit. Acetic acid is best known as the primary flavor component of vinegar.

Nick: /* As a precursor to other molecules in Lambic */

2015-01-17T00:30:28Z

As a precursor to other molecules in Lambic

← Older revision		Revision as of 00:30, 17 January 2015
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	CH3COOH + CH3CH2OH -> CH3COOCH2CH3 + H2O		CH3COOH + CH3CH2OH -> CH3COOCH2CH3 + H2O

	Ethyl acetate has a green-apple like scent in the concentrations that are likely to be found in lambic ~~[ref]~~.		Ethyl acetate has a green-apple like scent in the concentrations that are likely to be found in lambic.

	~~[1] MICROBIOLOGICAL ASPECTS OF SPONTANEOUS WORT FERMENTATION~~

	==References==		==References==

	<references />		<references />

Nick: /* In Lambic */

2015-01-17T00:29:51Z

In Lambic

← Older revision		Revision as of 00:29, 17 January 2015
Line 5:		Line 5:

	==In Lambic==		==In Lambic==
	The synthesis of acetic acid can occur through direct oxidation of ethanol, though this process is very slow in anaerobic conditions [ref]. Some bacteria, noteably Acetomonas and Acetobacter can catalyze the conversion of ethanol to acetic acid, greatly speeding up the process. The former can continue the oxidation process to fully convert ethanol to carbon dioxide and water, but the latter species is incapable of progressing beyond acetic acid. Both of these bacteria require oxygen for the reaction to take place, so the production of acetic acid occurs early in the fermentation process, when the wort is still well-oxygenated. After about 6 weeks, the production of acetic acid trails off and the concentration will remain the same until the end of fermentation <ref name=Oevelen77 >D. Van Oevelen, M. Spaepen, P. Timmermans and H. Verachtert, [http://onlinelibrary.wiley.com/doi/10.1002/j.2050-0416.1977.tb03825.x/abstract\|MICROBIOLOGICAL ASPECTS OF SPONTANEOUS WORT FERMENTATION IN THE PRODUCTION OF LAMBIC AND GUEUZE], 1977</ref>. As acetic acid bacteria are ever-present in the wort, exposure to excessive oxygen at any time during fermentation will lead to the formation of large amounts of acetic acid, sometimes up to 4 g/l [1], at which point the lambic is referred to as "hard", though it is still useful for blending <ref name=Guinard >Jean-Xavier Guinard , [[Books#Classic_Beer_Styles:_Lambic\|Classic Beer Styles: Lambic]], 1990</ref>.		The synthesis of acetic acid can occur through direct oxidation of ethanol, though this process is very slow in anaerobic conditions [ref]. Some bacteria, noteably Acetomonas and Acetobacter can catalyze the conversion of ethanol to acetic acid, greatly speeding up the process. The former can continue the oxidation process to fully convert ethanol to carbon dioxide and water, but the latter species is incapable of progressing beyond acetic acid. Both of these bacteria require oxygen for the reaction to take place, so the production of acetic acid occurs early in the fermentation process, when the wort is still well-oxygenated. After about 6 weeks, the production of acetic acid trails off and the concentration will remain the same until the end of fermentation <ref name=Oevelen77 >D. Van Oevelen, M. Spaepen, P. Timmermans and H. Verachtert, [http://onlinelibrary.wiley.com/doi/10.1002/j.2050-0416.1977.tb03825.x/abstract\|MICROBIOLOGICAL ASPECTS OF SPONTANEOUS WORT FERMENTATION IN THE PRODUCTION OF LAMBIC AND GUEUZE], 1977</ref>. As acetic acid bacteria are ever-present in the wort, exposure to excessive oxygen at any time during fermentation will lead to the formation of large amounts of acetic acid, sometimes up to 4 g/l <ref name=Oevelen77 >D. Van Oevelen, M. Spaepen, P. Timmermans and H. Verachtert, [http://onlinelibrary.wiley.com/doi/10.1002/j.2050-0416.1977.tb03825.x/abstract\|MICROBIOLOGICAL ASPECTS OF SPONTANEOUS WORT FERMENTATION IN THE PRODUCTION OF LAMBIC AND GUEUZE], 1977</ref>, at which point the lambic is referred to as "hard", though it is still useful for blending <ref name=Guinard >Jean-Xavier Guinard , [[Books#Classic_Beer_Styles:_Lambic\|Classic Beer Styles: Lambic]], 1990</ref>.

	==As a precursor to other molecules in Lambic==		==As a precursor to other molecules in Lambic==

Nick: /* In Lambic */

2015-01-17T00:29:29Z

In Lambic

← Older revision		Revision as of 00:29, 17 January 2015
Line 5:		Line 5:

	==In Lambic==		==In Lambic==
	The synthesis of acetic acid can occur through direct oxidation of ethanol, though this process is very slow in anaerobic conditions [ref]. Some bacteria, noteably Acetomonas and Acetobacter can catalyze the conversion of ethanol to acetic acid, greatly speeding up the process. The former can continue the oxidation process to fully convert ethanol to carbon dioxide and water, but the latter species is incapable of progressing beyond acetic acid. Both of these bacteria require oxygen for the reaction to take place, so the production of acetic acid occurs early in the fermentation process, when the wort is still well-oxygenated. After about 6 weeks, the production of acetic acid trails off and the concentration will remain the same until the end of fermentation [1]. As acetic acid bacteria are ever-present in the wort, exposure to excessive oxygen at any time during fermentation will lead to the formation of large amounts of acetic acid, sometimes up to 4 g/l [1], at which point the lambic is referred to as "hard", though it is still useful for blending <ref name=Guinard >Jean-Xavier Guinard , [[Books#Classic_Beer_Styles:_Lambic\|Classic Beer Styles: Lambic]], 1990</ref>.		The synthesis of acetic acid can occur through direct oxidation of ethanol, though this process is very slow in anaerobic conditions [ref]. Some bacteria, noteably Acetomonas and Acetobacter can catalyze the conversion of ethanol to acetic acid, greatly speeding up the process. The former can continue the oxidation process to fully convert ethanol to carbon dioxide and water, but the latter species is incapable of progressing beyond acetic acid. Both of these bacteria require oxygen for the reaction to take place, so the production of acetic acid occurs early in the fermentation process, when the wort is still well-oxygenated. After about 6 weeks, the production of acetic acid trails off and the concentration will remain the same until the end of fermentation <ref name=Oevelen77 >D. Van Oevelen, M. Spaepen, P. Timmermans and H. Verachtert, [http://onlinelibrary.wiley.com/doi/10.1002/j.2050-0416.1977.tb03825.x/abstract\|MICROBIOLOGICAL ASPECTS OF SPONTANEOUS WORT FERMENTATION IN THE PRODUCTION OF LAMBIC AND GUEUZE], 1977</ref>. As acetic acid bacteria are ever-present in the wort, exposure to excessive oxygen at any time during fermentation will lead to the formation of large amounts of acetic acid, sometimes up to 4 g/l [1], at which point the lambic is referred to as "hard", though it is still useful for blending <ref name=Guinard >Jean-Xavier Guinard , [[Books#Classic_Beer_Styles:_Lambic\|Classic Beer Styles: Lambic]], 1990</ref>.

	==As a precursor to other molecules in Lambic==		==As a precursor to other molecules in Lambic==

Adam at 02:34, 10 January 2015

2015-01-10T02:34:00Z

← Older revision		Revision as of 02:34, 10 January 2015
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	[1] MICROBIOLOGICAL ASPECTS OF SPONTANEOUS WORT FERMENTATION		[1] MICROBIOLOGICAL ASPECTS OF SPONTANEOUS WORT FERMENTATION

			==References==

			<references />

Nick at 02:26, 10 January 2015

2015-01-10T02:26:05Z

← Older revision		Revision as of 02:26, 10 January 2015
Line 5:		Line 5:

	==In Lambic==		==In Lambic==
	The synthesis of acetic acid can occur through direct oxidation of ethanol, though this process is very slow in anaerobic conditions [ref]. Some bacteria, noteably Acetomonas and Acetobacter can catalyze the conversion of ethanol to acetic acid, greatly speeding up the process. The former can continue the oxidation process to fully convert ethanol to carbon dioxide and water, but the latter species is incapable of progressing beyond acetic acid. Both of these bacteria require oxygen for the reaction to take place, so the production of acetic acid occurs early in the fermentation process, when the wort is still well-oxygenated. After about 6 weeks, the production of acetic acid trails off and the concentration will remain the same until the end of fermentation [1]. As acetic acid bacteria are ever-present in the wort, exposure to excessive oxygen at any time during fermentation will lead to the formation of large amounts of acetic acid, sometimes up to 4 g/l [1], at which point the lambic is referred to as "hard", though it is still useful for blending [2].		The synthesis of acetic acid can occur through direct oxidation of ethanol, though this process is very slow in anaerobic conditions [ref]. Some bacteria, noteably Acetomonas and Acetobacter can catalyze the conversion of ethanol to acetic acid, greatly speeding up the process. The former can continue the oxidation process to fully convert ethanol to carbon dioxide and water, but the latter species is incapable of progressing beyond acetic acid. Both of these bacteria require oxygen for the reaction to take place, so the production of acetic acid occurs early in the fermentation process, when the wort is still well-oxygenated. After about 6 weeks, the production of acetic acid trails off and the concentration will remain the same until the end of fermentation [1]. As acetic acid bacteria are ever-present in the wort, exposure to excessive oxygen at any time during fermentation will lead to the formation of large amounts of acetic acid, sometimes up to 4 g/l [1], at which point the lambic is referred to as "hard", though it is still useful for blending <ref name=Guinard >Jean-Xavier Guinard , [[Books#Classic_Beer_Styles:_Lambic\|Classic Beer Styles: Lambic]], 1990</ref>.

	==As a precursor to other molecules in Lambic==		==As a precursor to other molecules in Lambic==
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	[1] MICROBIOLOGICAL ASPECTS OF SPONTANEOUS WORT FERMENTATION		[1] MICROBIOLOGICAL ASPECTS OF SPONTANEOUS WORT FERMENTATION
	~~[2] Guinard, "Lambic"~~