Talk:Yeast/Archive 1

What does this sentence mean?
The Ecology section had the bold sentence in it:

An Indian study of seven bee species and 9 plant species found that 45 species from 16 genera colonise the nectaries of flowers and honey stomachs of bees. Most were members of the Candida genus; the most common species in honey stomachs was Dekkera intermedia and in flower nectaries, Candida blankii.[7] Flowers that are colonised by yeasts have less nectar to bees in them. Yeast colonising nectaries of the Stinking Hellebore have been found to raise the temperature of the flower, which may aid in attracting pollinators by increasing the evaporation of volatile organic compounds.[3][8]

Does anyone know what that was supposed to mean? It sounds like it's saying yeast inhibits nectar production, making flowers less attractive to bees, but that kind of goes against the next sentence. I've removed it for now since it was unintelligible, but someone who understands should rephrase and put it back... Personman (talk) 17:15, 19 June 2010 (UTC)

Kombucha vs Kvass
The page states that kombucha is known in Eastern Europe as kvass. In fact, these are two different things - kombucha is made from tea, kvass is made from bread. Avatariks (talk) 02:35, 2 May 2010 (UTC)

Intro
There is repeat of the same content of this page in topic " Yeast " and "Yeast_Cell" this may increase the data base volume the pages are,

http://en.wikipedia.org/wiki/Yeast_cell

http://en.wikipedia.org/wiki/Yeast

Introduction is way two complicated. Cut it down and just say what it is and were it is used. Be general! —Preceding unsigned comment added by 69.110.5.244 (talk) 21:56, 2 December 2007 (UTC)

Physiology of Yeast- Possible copyright issues
I have made some minor changes to the Physiology section of yeast. The tone sounds like it might have been copied from some sort of childrens website. I have removed the signature "by James Boyd Dunaway" for GFDL reasons and if this content requires this signature for copyright reasons I suggest a total re-write of this 1st paragraph of that section. Re-reading it, there would seem to be straying off topic of physiology and giving a full description of yeast. -alex- 15:25, 28 October 2006 (UTC)

"Facultatively fermentative" is not normally used to describe microbial physiology. Rather, the term employed is "facultatively anaerobic". This indicates that the organism is capable of generating metabolic energy through substrate level phosphorylation - generally known as glycolysis.

Yeast and light
Does yeast need light to carry out their life activities?
 * No. Yeasts are not photosynthetic.  They are saphrophytic.

How do I develop a hypothesis?
 * Start with observations - draw generalizations from the evidence that can be tested experimentally.


 * To the best of my knowledge, yeast does not photosynthesize, and does not require light. Bread will rise very happily in the dark.  If anything, direct sunlight is probably damaging to yeast.  --PJF (talk) 01:02, 8 Apr 2005 (UTC)
 * from baking bread as a child and brewing beer as an adult, i seem to remember that yeast is damaged by light.


 * Yeasts are loosely connected fungus colonies in which any individual cell has a natural tendency of "deconnecting" from the colony and float freely. This feature is very useful in winemaking/brewing, as the yeast colony will migrate and expand, processing the whole volume of liquid. Hugo Dufort 07:40, 27 September 2006 (UTC)

Wow nevermind, kinda a blow to my pride but Yeast are indeed part of kingdom fungi. Strange, I guess now that I think about it fungus-like protista and normal fungi are more similar that I stated.- Moshe Constantine Hassan Al-Silverburg 06:25, 17 November 2005 (UTC)

History and Nature?
This article should have more information on the history and natural condition of yeast because that is what I came here to find out about. I am surprised that such a major thing as yeast has such a small article. What does natural yeast look like, where and how does it grow/live? How was it originally "domesticated" and how has it been cultured over the ages?

i agree. Yeast is something that should have a lot of info on it and i am surprised that there is so little.

What about the evolution of yeast? This artical is sooo incomplete. —Preceding unsigned comment added by 69.110.5.244 (talk) 21:52, 2 December 2007 (UTC)

Cleanup
I have removed some unnecessary language info from this article. Ajfweb 10:30, 29 November 2006 (UTC)
 * This information was not unnecessary, and provided links to the same article in other languages. I have since restored the links. ◄  §ĉҺɑʀκs  ►  11:40, 29 November 2006 (UTC)

Merge
Please discuss whether to merge Yeast and Yeast (baking) at Talk:Yeast (baking). Thanks. —Quarl (talk) 2006-12-18 02:27Z 

These should also be merged somehow: —Quarl (talk) 2006-12-19 00:50Z 
 * Brewer's yeast (to which Bottom and top fermenting yeast should be merged)
 * Nutritional yeast
 * Yeast extract


 * Yes, all should be merged. If it gets too long, we can always summarize and spin off new articles, but for now the Yeast page is sufficiently small that adding the others in would help rather than hurt. Coemg e nus 14:19, 20 December 2006 (UTC)


 * Oppose merge. Yeast is an organism and yeast extract is a specific food ingredient.  We don't merge catsup into Tomato.  The merge, which seems already to have been performed, is thus premature.  Badagnani 02:03, 23 December 2006 (UTC)
 * How long are you meant to wait before a merge is performed? Also you have not provided comments why we should not merge Brewer's yeast and Nutritional yeast into Yeast. ◄ §ĉҺɑʀκs  ►  02:46, 23 December 2006 (UTC)

I see the point about Yeast extract. Let's hold off on that one for now but merge the others. —Quarl (talk) 2006-12-23 03:26Z 


 * Yeast is about the organism and the other three articles are about very specific foods, additives, or ingredients made from specific strains/species of yeast and used for specific purposes. I believe all three merit consideration on their own.  Badagnani 09:12, 23 December 2006 (UTC)
 * Brewer's yeast and Nutritional yeast are also about the organism, and there isn't enough content for separate articles yet. —Quarl (talk) 2006-12-23 09:20Z 
 * I find the Brewer's yeast article a combination of the content from Nutritional yeast and Bottom and top fermenting yeast. I have already merged the entire content from this article into the brewing and nutritional supplement sections of the Yeast article, and think that this article could now be a redirect to Yeast because it is a mixture of topics. The Nutritional yeast article is a small article that talks about the nutritional benefits of yeast, which I have already incorporated the entire content into the nutritional supplement section of the Yeast article. I do not see a need to have this split from the main topic. I do however concede that Yeast extract as an ingredient should stay as its own article, as Badagnani has made a good point. ◄  §ĉҺɑʀκs  ►  10:40, 23 December 2006 (UTC)

Improvement Drive
I nominated this article for the improvement drive and i just want to thank everyone who voted for it and has contributed, this article is really looking very very good now. Thanks so much! Benbread 13:24, 27 December 2006 (UTC)
 * I had this article on my "things to do list" for quite some time so it was great to have an excuse to get it up to scratch! I'm hoping to have it to GA status soon. ◄  §ĉҺɑʀκs  ►  13:36, 27 December 2006 (UTC)

Further improvement
Yeast genetics and cell biology as ways to investigate eukaryotic cells isn't really dealt with. Both S cerevisiae and S pombe have fully-sequenced genomes, these aren't discussed. Vaginal yeast infections aren't discussed. Mention of conversion of sugars into ethanol as well as carbon dioxide in 'Baking' section, which affecs the flavour of bread.

Overall, excellent. TimVickers 05:17, 9 January 2007 (UTC)
 * The reference to Fleischmann’s Yeast is a bit US-centric (IMO). 20.133.0.14 09:06, 5 March 2007 (UTC)

There's some contradictory information in this and related articles, or at the very least a lack of detail. Specifically this phrase: "Many types of yeasts are used for making many foods: Baker's yeast in bread production, brewer's yeast in beer fermentation, yeast in wine fermentation and for xylitol[18] production."

According to the article on Saccharomyces cerevisiae, the term "baker's yest" and "brewer's yeast" both refer to S. cerevisiae (Although it mentions vaguely that other yeasts are used in brewing, without mentioning which ones). Josh 03:25, 31 August 2007 (UTC)

Cite needed
There should be a cite that yeast are "the worlds most primitive form of the reptilian genera." —The preceding unsigned comment was added by 69.231.75.66 (talk) 19:17, 24 January 2007 (UTC).
 * This was vandalism and has since been reverted. ◄  §ĉҺɑʀκs  ►  02:08, 25 January 2007 (UTC)

Pictures floated right
I've noticed all the pictures in this article are floated right making it seems a little bit crowded, would it not be better to alternate left and right?--Grimboy 20:58, 31 January 2007 (UTC)
 * I prefer it this way as it makes the article easier to read and provides visual coherence, however I'm open to it alternating if it doesn't break the sections. ◄  §ĉҺɑʀκs  ►  01:26, 1 February 2007 (UTC)
 * I don't suppose it particularly matters on further reflection. --Grimboy 20:58, 2 February 2007 (UTC)

Grammar check
In the second paragraph there is this confusing sentence: It is also extremely important as a model organism in modern cell biology research, and is the most thoroughly researched eukaryotic microorganism, which gathers information into the biology of the eukaryotic cell and ultimately human biology.  My suggestion is to eliminate the dangling modifier like so: It is an important model organism, and is the most thoroughly researched eukaryotic microorganism in cell biology research, which gathers information into the biology of the eukaryotic cell and ultimately human biology. Jaco66 01:05, 8 March 2007 (UTC)
 * Wow, where did you get the blue from? The second sentence is better English but I think both sentences are too long, how about splitting them up with a ;? Maikel 01:05, 18 September 2007 (UTC)

Yeast (3 votes, stays until May 1st)
Support:
 * 1) Peter G Werner 00:37, 13 January 2007 (UTC)
 * 2) Cas Liber 01:34, 13 January 2007 (UTC)
 * 3) M&amp;NCenarius 04:29, 16 January 2007 (UTC)

Comments:


 * Lets not forget the "lower" fungi, and this is certainly a very important group. "Yeast" is already at GA status and is long enough to potentially be a Feature Article. Needs a little more on yeast taxonomy, IMO, but otherwise its in really good shape. Peter G Werner 00:37, 13 January 2007 (UTC)


 * I have to agree, this one is not far off FA candidacy I think. Depending on people's energy levels might be a good one to get over the line...Cas Liber 01:34, 13 January 2007 (UTC)

Answers
1. Baker's yeast? 15-20° C (but what do you mean by "in any situation"?). Maikel 01:02, 18 September 2007 (UTC)

2. Does the ethonol that yeast produces kill it? —Preceding unsigned comment added by 80.148.27.246 (talk) 00:12, 22 April 2009 (UTC)

Contrast yeast and mold
I am not a mycologist, but I suggest that the sentence "By contrast, microscopic fungi that grow as multicellular filaments are called molds" be added somewhere in the first paragraph. Bayle Shanks 08:00, 14 July 2007 (UTC)

Photo of grapes is misleading
The caption on the photograph of grapes claims that the blush on the berries is yeast. It is not. The blush is wax on the grape surface. Yeast may be there also, but you can't see it. I think this photo and its caption should be removed. There are many opportunities to show pictures of bona fide interactions of yeast and grapes. Phytism 18:29, 6 August 2007 (UTC)
 * In vinum veritas, eh? Maikel 01:00, 18 September 2007 (UTC)
 * The main article developer is not active on Wikipedia at present, I may have a look at it soon when I clear some other stuff.cheers, Casliber (talk · contribs) 01:08, 18 September 2007 (UTC)

Just say no to eggs and sugar
Quote: The use of potatoes, water from potato boiling, eggs, or sugar in a bread dough accelerates the growth of yeasts. ... this is not true to my knowledge for eggs and household sugar (succrose). The fat from the yolk inhbits the yeast growth, and the household sugar does likewise by binding essential water to itself. So in fact eggs and household sugar inhibit the growth of yeasts. Maikel 01:00, 18 September 2007 (UTC)


 * The main article developer is not active on Wikipedia at present, I may have a look at it soon when I clear some other stuff.cheers, Casliber (talk · contribs) 01:09, 18 September 2007 (UTC)


 * It would take a lot of sugar to inhibit yeast by reducing water availability, somewhere around 40%. Small amounts, say a few tablespoons per loaf, really make the yeast in the dough grow faster. The statement seems to be accurate as written; bakers do add sugar to dough to accelerate the growth of yeast.Phytism 02:17, 20 October 2007 (UTC)


 * Maikel: How do you know that about the eggs and the sugar? — Bigwyrm watch me wake me 06:21, 20 October 2007 (UTC)

POV issue
"The resulting bread would have been lighter and more tasty than the normal flat, hard cake."

The bolded bit is POV in my opinion. lol!! Jake the Editor Man  ( talk  ) 17:00, 13 December 2007 (UTC)
 * The article refers to leavened bread being "more tasty" than unleavened bread. Considering the impact of leavening bread on the human diet, I think there is ample historical evidence for people finding it more tasty. It sounds a bit colloquial, but I don't see a POV problem. Phytism (talk) 01:16, 29 January 2008 (UTC)

Taste
i looked through quickly and I saw no mention of yeast's taste —Preceding unsigned comment added by Phil Ian Manning (talk • contribs) 12:32, 2 January 2008 (UTC)
 * It tastes yeasty. Gigs (talk) 08:35, 10 June 2008 (UTC)

Your more than welcome to go taste some... People don't normally eat plain yeast though... so I'm not sure it matters. —Preceding unsigned comment added by Frupert (talk • contribs) 09:53, 10 June 2008 (UTC) The taste is important for beer and wine brewers. Over-fermented wine tastes, well, yeasty. — Preceding unsigned comment added by Dnlprck (talk • contribs) 07:07, 20 April 2011 (UTC)

Food spoilage section>--- low ph (5.0 or lower)
I found part of this part quite confusing to read, esp the "low ph (5.0 or lower)" which is at the first sentence.

Now I do realize what it means now, but I still suggest a rephrase of the phrase in the bracket...

How about (Numerically 5.0 or higher) —Preceding unsigned comment added by Wiknerd (talk • contribs) 17:49, 6 May 2008 (UTC)

Useless Bit at Bottom
I've removed "Yeast is ver important to everyday life, men need it for beer and woen need it for wine, children need it to do experiments and it can be v" As it sounds like it was written by a two year old, makes no sense, and is most likely vandalism : D ~Frupert —Preceding unsigned comment added by Frupert (talk • contribs) 09:11, 10 June 2008 (UTC)

Question-- what defines a yeast?
Does yeasts have some intrinsic trait that qualifies a particular species as being a "yeast" rather than just generically being a "fungus"? What is special about all (or most) of the species of yeast that qualifies them as yeasts? --Alecmconroy (talk) 15:05, 2 July 2008 (UTC)

I believe that the term yeast is given to any fungus that exhibits a unicellular nonfilamentous (or nonmycelial) growth form. There are fungi that can grow unicellularly or as a mycelium, and they are usually referred to as dimorphic. Woodlore (talk) —Preceding comment was added at 23:32, 9 July 2008 (UTC)


 * This definitely needs to be clarified, this paper written in 1992 says: "The current definition of yeasts may be taken as that adopted in the latest edition of the leading monograph on yeasts (Kreger van Rij, 1984): 'unicellular fungi reproducing by budding or fission'. Accordingly, only organisms with colourless cells, or producing red, orange, and yellow pigments are included; whilst fungi characterized by yeast phases only under specific conditions, such as Ajellomyces, Histoplasma and Aureobasidium, are not considered."


 * It would be good to know if this is still the accepted definition or not, the article really isn't clear as to what is and what isn't a yeast which is a pretty big omission. We should really have a whole section on taxonomy I guess. Smartse (talk) 20:13, 14 February 2010 (UTC)

Kefir
In the interest of fairness, if there is a section on kombucha, there should be one on kefir as well. elpincha (talk) 17:30, 26 September 2008 (UTC)
 * I've added a mention of kefir to the article now in the non-alcoholic beverage section. Smartse (talk) 20:10, 14 February 2010 (UTC)

Identification codes of the topic for .....????
food safety, to distiguish its alternatives

--222.67.217.239 (talk) 10:21, 18 March 2010 (UTC) Let the topic Ω — Yeast --222.64.27.154 (talk) 02:06, 20 March 2010 (UTC)

--222.64.27.154 (talk) 02:13, 20 March 2010 (UTC)

Additional info --222.67.217.239 (talk) 10:30, 18 March 2010 (UTC)
 * http://scholar.google.com/scholar?as_q=yeast+leavening+dough&num=10&btnG=Search+Scholar&as_epq=&as_oq=&as_eq=&as_occt=title&as_sauthors=&as_publication=&as_ylo=&as_yhi=&as_sdt=1.&as_sdtp=on&as_sdts=5&hl=en

--222.67.217.239 (talk) 10:38, 18 March 2010 (UTC)
 * http://scholar.google.com/scholar?hl=en&q=allintitle%3A+yeast+type+dough&btnG=Search&as_sdt=2000&as_ylo=&as_vis=0

--222.67.217.239 (talk) 10:43, 18 March 2010 (UTC)
 * http://www.bri.com.au/

Info about the topics of yeast and fungal infections.....

 * http://scholar.google.com/scholar?as_q=yeast+infection&num=10&btnG=Search+Scholar&as_epq=&as_oq=&as_eq=&as_occt=title&as_sauthors=&as_publication=&as_ylo=&as_yhi=&as_sdt=1.&as_sdtp=on&as_sdts=5&hl=en

--222.64.27.154 (talk) 02:23, 20 March 2010 (UTC)
 * http://scholar.google.com/scholar?hl=en&q=allintitle%3A+fungal+infection&btnG=Search&as_sdt=2000&as_ylo=&as_vis=0

It looks that few of the publications are there probably due to the fact that baker's yeast is heat resistant --124.78.215.31 (talk) 08:19, 20 March 2010 (UTC)
 * http://www.google.com/search?num=10&hl=en&q=allintitle%3A%20yeast%20infection%20microwave&sa=N&tab=sw

Yeast - Glycogen Or Starch?
Does Yeast contain Starch or Glycogen? Interesting Question. —Preceding unsigned comment added by 86.152.45.91 (talk) 14:34, 21 January 2011 (UTC)
 * Certainly glycogen, I'm not sure about starch, and searching for information is difficult due to the abundance of sources discussing yeast eating starch. I'd hazard a guess that they don't, since AFAIK, only plants (broadly construed) have starch, but I may be wrong. SmartSE (talk) 15:08, 21 January 2011 (UTC)

"The company created yeast that would rise twice as fast, reducing baking time."
I have to question the logic and accuracy of this statement. I think the author meant to say that rising time was cut in half. Baking time would remain the same. — Preceding unsigned comment added by VaxAlpha (talk • contribs) 18:53, 19 November 2011 (UTC)
 * Thanks for pointing that out. I've changed the section, merging the "rising twice as fast" part into the sentence before. SmartSE (talk) 20:32, 19 November 2011 (UTC)

Bloom
The article refers in yeast and the caption to the figure to yeasts on the surface of grapes forming a visible bloom. This is incorrect, although it may be a common misconception. The bloom has nothing whatsoever to do with yeast - it is caused by epicuticular wax crystals that are naturally secreted by the epidermis of the grape. Yeast is naturally present on the surfaces of grapes but not in sufficient numbers to form a visible coating. I suggest the article should be modified to remove this error. see e.g. Koch, K. and Ensikat, H.-J. The hydrophobic coatings of plant surfaces: epicuticular wax crystals and their morphologies, crystallinity and molecular self-assembly. Micron, 39, 759-772. Plantsurfer (talk) 11:01, 6 April 2012 (UTC)
 * The error has been excised ... thanks for the note. Sasata (talk) 21:03, 6 April 2012 (UTC)
 * Thanks. Plantsurfer (talk) 21:45, 6 April 2012 (UTC)

Two questions
"A weak solution of water and sugar." Solution of what in what? Should mean a small amount of yeast and undefined amount of sugar dissolved in water? Does yeast dissolve or rather disperge in water?

"... and then left to rise, sometimes until it has doubled in size." Linearly, means to the 8-fold volume? --Helium4 (talk) 17:21, 29 July 2012 (UTC)

Photos
See http://www.flickr.com/search/?q=yeast&l=cc

Questions
1. What is the most ideal temperature for yeast to rise in any situation?