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Traditionally, the mousy/Cheerios® flavor from THP is considered an off flavor in both wine and sour beer. There is some debate and differing opinions as to whether or not a small amount of THP flavor is allowable (or even enjoyable) in sour beers, however most consider any level to be an off flavor <ref>[https://www.facebook.com/groups/MilkTheFunk/permalink/1864484553579750/ MTF discussion on whether or not THP should always be considered an off-flavor. 10/27/2017.]</ref>. In wine, THP is also generally considered an off-flavor, although to some people a small amount of THP is acceptable in natural wine. It has greatly been eliminated as a problem in wine making due to sulfite sulphite usage and better controlled fermentations. However, in recent years there has been an increase in the popularity of natural wine which has a higher chance of being affected by THP. There has therefore also been a recent increased attention to THP in wine due to the increased popularity of natural wine <ref>[https://www.sfchronicle.com/wine/article/There-s-a-mouse-in-your-wine-14465005.php Esther Mobley. San Francisco Chronicle. 09/24/2019. Retrieved 09/25/2019.]</ref>.
In food, Tetrahydropyridines are associated with the aroma of baked goods such as white bread, popcorn, and tortillas, and is formed by Maillard reactions during heating. These versions of THP have a different chemical form than the forms produced by microbes, but they can have a similar flavor.
Tempère et al. (2019) developed what they suggest is a better way to test for mousy off-flavor in wine via oral sensory, specifically as a way to enable panelists who are not as sensitive to THP to detect it during sensory testing. They compared the alkaline strips method to a method where the wine's pH is increased by adding sodium bicarbonate to a pH of 5 and a pH of 7. This mild base is contained in human saliva. At a pH of 5, sensory panelists were more easily able to detect APY and to correctly order the intensity of APY in wine than when they used alkaline strips. For example, the range of detection level for all panelists went from a range of 15 - 300 µg/L to a range of 0.3 - 30 µg/L. At a pH of 7, panelists were not as easily able to detect the aroma of APY. Keep in mind that this test does not reflect the real world tasting of wine since the pH would never be raised during normal consumption, but it could be used by a sensory program as a way to more reliably detect smaller amounts of APY in wine <ref name="Tempère_2019">[https://oeno-one.eu/article/view/2350 Comparison between standardized sensory methods used to evaluate the mousy off-flavor in red wine. Tempère, S., Chatelet, B., de Revel, G., Dufoir, M., Denat, M., Ramonet, P.-Y., Marchand, S., Sadoudi, M., Richard, N., Lucas, P., Miot-Sertier, C., Claisse, O., Riquier, L., Perello, M.-C., & Ballestra, P. 2019. DOI: https://doi.org/10.20870/oeno-one.2019.53.2.2350.]</ref>.
Other techniques for detected THP in food have been developed, which might be applicable to wine or beer. For example, Grimm et al. (2001) developed a technique for detecting 2-acetyl pyrroline (APY or 2AP) in rice. The rice samples had to be heated to 80-85°C in order to extract the volatile APY, and then APY levels in the headspace of the rice container could be detected using solid phase microextraction (SPME) with fibers that operate at the higher temperatures <ref>[https://www.ncbi.nlm.nih.gov/pubmed/11170584 Screening for 2-acetyl-1-pyrroline in the headspace of rice using SPME/GC-MS. Grimm CC, Bergman C, Delgado JT, Bryant R. 2001.]</ref>. It isn't known if such methods would also work for measuring THP compounds in beer or wine, but they could provide a potential option for beer and wine researchers. Cider makers have used a baking soda in water solution to help detect THP. Dissolve a small amount of baking soda in water, swish the solution in your mouth for a few seconds, and then spit it out. While the pH of the saliva in your mouth is raised from the baking soda solution, taste the beer/wine/cider to more easily detect THP <ref>[https://groups.google.com/g/cider-workshop/c/a9JcCERQTYk?pli=1 "testing for mouse". Testing for Mouse. Retrieved 04/06/2021.]</ref>.
The effectiveness of these methods in beer has not been reported to our knowledge (please report any research or anecdotes in the [https://www.facebook.com/groups/MilkTheFunk/ MTF Facebook group]).
===APY===
2-acetyl pyrroline (abbreviated: APY, ACPY, or AP) is a more volatile but more potent form of THP. It has a significantly stronger odor and lower odor threshold in wine than ATHP. It can also be found in damp pearl millet, toasted bread, taco shells, tortilla chips, boiled potatoes, cooked sweet corn products, roasted sesame seeds, pan-fired green teas, cured tobacco leaves, peanut and pumpkin seed oils, honey, several soy-based products, and more aromatic rice such as Indian Basmati, as well as many other foods. APY has also been detected in a pale lager beer from Bavaria <ref>[https://link.springer.com/article/10.1007/BF01190873 Primary odorants of pale lager beer. Peter Schieberle. 1991.]</ref>. APY from microbial metabolism is primarily produced by heterofermentative LAB (see [[Tetrahydropyridine#Lactic_Acid_Bacteria|below]]). In food, APY formation is due to cooking and thought to be associated with Maillard reactions, and its presence ages out quickly in food. For example, Schieberle (1989) showed that heating up yeast and sucrose produced APY, simulating how APY could be produced during baking bread <ref><[https://pubs.acs.org/doi/10.1021/bk-1989-0409.ch025 Formation of 2-Acetyl-l-pyrroline and Other Important Flavor Compounds in Wheat Bread Crust. Peter Schieberle. 1989. DOI: 10.1021/bk-1989-0409.ch025.]</ref>. It is extremely volatile; so much so that the food industry has created powdered forms of APY to increase the flavor stability of some foods associated with it. Some plants such as rice crops, Pandan leaves (''Pandanus amaryllifolius''), "bread flowers" (''Vallaris glabra''), Myabi muskmelon fruit, chempedak fruit and jackfruit contain varying levels of APY naturally <ref name="Snowdon"></ref><ref name="Grbin_1996" /><ref name="Adams_2005">[http://pubs.acs.org/doi/abs/10.1021/cr040097y Chemistry of 2-Acetyl-1-pyrroline, 6-Acetyl-1,2,3,4-tetrahydropyridine, 2-Acetyl-2-thiazoline, and 5-Acetyl-2,3-dihydro-4H-thiazine: Extraordinary Maillard Flavor Compounds. An Adams and Norbert De Kimpe. 2005.]</ref><ref>[https://www.sciencedirect.com/science/article/pii/S1672630823001105 Abiotic and Biotic Factors Controlling Grain Aroma along the Value Chain of Fragrant Rice: A Review. Ayut Kongpun, Tonapha Pusadee, Pennapa Jaksomsak, Kawiporn chinachanta, Patcharin Tuiwong, Phukjira Chan-In, Sawika Konsaeng, Wasu Pathom-Aree, Suchila Utasee, Benjamapohn Wangkaew, Chanakan Prom-U-Thai. Rice Science. 2023. https://doi.org/10.1016/j.rsci.2023.11.004.]</ref>.
===Unidentified "Transient" Forms===
[[File:THP Pathway.JPG|thumb|400|Proposed pathway for THP production by ''Brettanomyces'' <ref name="Elsevier">[https://books.google.com/books?hl=en&lr=&id=KJJwAgAAQBAJ&oi=fnd&pg=PA346&dq=brettanomyces+Tetrahydropyridine&ots=ktbn8PR_fF&sig=r3lkcV-gBa-pK86HSOgFDVIJVDk#v=onepage&q=brettanomyces%20Tetrahydropyridine&f=false Managing Wine Quality: Oenology and Wine Quality. A Reynolds Elsevier, Sep 30, 2010. Pg 359.]</ref>]]
It is thought that THP in mousy wines/beers is mostly produced by microorganisms. All species of ''[[Brettanomyces]] '' can produce forms of tetrahydropyridine in varying amounts, although some below threshold. Additionally, Lactic Acid Bacteria (LAB) including ''[[Lactobacillus]] '' and ''[[Pediococcus]] '' can produce forms of THP. Acetic Acid Bactera (AAB) has also been demonstrated to produce forms of THP <ref name="Snowdon"></ref><ref name="Grbin_2000" />.
Moulis et al. (2023) studied THP production by 22 strains of ''Brettanomyces bruxellensis'', 20 strains of ''Oenococcus oeni'' and 10 strains of ''Lentilactobacillus hilgardii'' (formerly classified as ''Lactobacillus hilgardii''), all of which have been reported to produce THP compounds. They found that all strains could produce ATHP, but not all strains could produce ETHP or APY. This variability was determined mostly by species, but also by strain. for example, all of the 22 ''B. bruxellensis'' strains only produced ATHP and ETHP and not APY. Variability between strains was less pronounced for the species ''L. hilgardii'' compared to the ''B. bruxellensis'' and ''O. oeni'' strains (different strains of ''B. bruxellensis'', for example, produced much different levels of ATHP/ETHP, where as every strain of ''L. hilgardii'' produced relatively the same amount of APY). The researchers also noted that repeatability of THP levels was difficult to achieve, and they owed this to unknown variables such as the physiological state of the cells at time of inoculation into the test media. Interestingly, there was no correlation between strain genealogy and how much THP they produced. The researchers also isolated other species from 25 French wines with mouse taint, including ''S. cerevisiae'', ''Pichia manshurica'', ''Priceomyces carsonii'', ''Pediococcus parvulus'', but none of these strains produced THP in the test growth media <ref name="Moulis_2023" />. ===''Brettanomyces''===
Although the exact pathway is not known for ''Brettanomyces'' (several are proposed), the conditions for THP production are well documented. ATHP is produced by metabolizing the amino acid L-lysine or D-lysine <ref name="Grbin_2007" />, along with ethanol and a glucose or fructose molecule. Iron is also needed for THP production, although its exact role in biosynthesis is not known <ref name="Snowdon"></ref>. As with other amino acids, lysine is taken up by ''Saccharomyces'' during fermentation and then released after fermentation. Levels of lysine fluctuate slightly throughout fermentation but are generally high throughout a beer's lifetime (including after fermentation) <ref>[http://link.springer.com/article/10.1385/CBB:46:1:43 The α-aminoadipate pathway for lysine biosynthesis in fungi. Hengyu Xu, Babak Andi, Jinghua Qian, Ann H. West , Paul F. Cook. Sept 2006.]</ref><ref>[http://pubs.acs.org/doi/abs/10.1021/bi9829940 Lysine Biosynthesis in Saccharomyces cerevisiae: Mechanism of α-Aminoadipate Reductase (Lys2) Involves Posttranslational Phosphopantetheinylation by Lys5. David E. Ehmann , Amy M. Gehring , and Christopher T. Walsh. 1999.]</ref><ref>[http://onlinelibrary.wiley.com/doi/10.1002/j.2050-0416.2007.tb00249.x/abstract Elucidation of the Role of Nitrogenous Wort Components in Yeast Fermentation. C. Lekkas, G.G. Stewart, A.E. Hill, B. Taidi and J. Hodgson. May 2012.]</ref><ref>[http://www.sciencedirect.com/science/article/pii/S0308814699000710 Proteins and amino acids in beers, their contents and relationships with other analytical data. S. Gorinstein, M. Zemsera, F. Vargas-Albores, J-L. Ochoa, O. Paredes-Lopez, Ch. Scheler, J. Salnikow, O. Martin-Belloso, S. Trakhtenberg. 1999.]</ref>. Wheat generally has a slightly lower amount of lysine than barley, and oats have a slightly higher amount of lysine than barley <ref>[http://www.aaccnet.org/publications/cc/backissues/1983/Documents/chem60_461.pdf Amino Acid Composition of Six Grains and Winter Wheat Forage. Morey, D.D. 1983.]</ref><ref>[https://diy.soylent.com/ingredients/oats "Oats". DIY Soylent website. Retrieved 02/07/2017.]</ref><ref>[https://diy.soylent.com/ingredients/barley-malt-flour "Barley malt flour". DIY Soylent website. Retrieved 02/07/2017.]</ref><ref>[https://diy.soylent.com/ingredients/wheat-flour-wholegrain "Wheat flour, whole-grain". DIY Soylent website. Retrieved 02/07/2017.]</ref>. In red wine, yeast autolysis releases many amino acids including lysine <ref>[https://pubs.acs.org/doi/abs/10.1021/jf9803381 Changes in the Amino Acid Composition of the Different Nitrogenous Fractions during the Aging of Wine with Yeasts. Victoria Moreno-Arribas, Encarnación Pueyo, M. Carmen Polo, and Pedro J. Martín-Álvarez. 1998. DOI: 10.1021/jf9803381.]</ref><ref>[https://www.ncbi.nlm.nih.gov/pubmed/12483471 Influence of the yeast strain on the changes of the amino acids, peptides and proteins during sparkling wine production by the traditional method. Martínez-Rodríguez AJ, Carrascosa AV, Martín-Alvarez PJ, Moreno-Arribas V, Polo MC. 2002. DOI: 10.1038/sj.jim.7000323.]</ref><ref>[http://oeno-one.eu/article/view/974 New trends on yeast autolysis and wine ageing on lees: a bibliographic review. Caroline Fornairon-Bonnefond, Carole Camarasa, Michel Moutounet, Jean-Michel Salmon. 2002.]</ref>. Aging beer on trub and its effects on THP production has not been studied, but it might not be a factor in beer since lysine levels are high in beer regardless of yeast autolysis <ref>[https://www.facebook.com/groups/MilkTheFunk/permalink/2054994917862045/?comment_id=2055489394479264&reply_comment_id=2055715194456684&comment_tracking=%7B%22tn%22%3A%22R%22%7D Richard Preiss. Milk The Funk Facebook group thread on on yeast autolysis impact on THP. 04/10/2018.]</ref>.
The production of ATHP is not efficient, meaning that the amount of ATHP produced is not proportional to the amount of L-lysine consumed. Therefore, the production of ATHP appears to be a byproduct (secondary metabolite) of L-lysine catabolism <ref name="Snowdon"></ref>. ATHP is further metabolized into ETHP by ''Brettanomyces'', although not much is known about this metabolic process <ref>[http://ucce.ucdavis.edu/files/repositoryfiles/Joseph_5_Aromatic_Diverswity_of_Brettanomyces-82350.ppt Joseph, C.M. Lucy. ''Aromatic Diversity of Brettanomyces''. U.C. Davis. Retrieved 3/10/2015.]</ref><ref name="Snowdon"></ref>. ETHP has a significantly higher taste threshold, and is often not detected in contaminated wine <ref name="Oelofse"></ref>.
Although ''Brettanomyces'' is capable of producing APY from L-ornithine <ref name="Grbin_2007" />, the amount produced is much less than that of LAB and high amounts of L-ornithine are required. In wine, there isn't enough L-ornithine present to production significant amounts of APY from L-ornithine. Therefore, the presence of APY (which is much easier to detect aromatically than ATHP) indicates a bacterial contamination in wine (it is unknown if this applies to beer) <ref name="Snowdon"></ref>. Additionally, Moulis et al. (2023) found that out of 25 French wines with THP, only 20% of them had ''B. bruxellensis'' in them, indicating that THP is mostly produced by bacteria or chemically in wine <ref name="Moulis_2023" />.
The presence of the "mousy off-flavor" caused by forms of THP appears to be temporary in beer. Although not much is known about the degradation or metabolic breakdown of ATHP/ETHP, it tends to age out of beer after 2-6 months. Since the odor/taste threshold for ETHP is much higher than ATHP, and ATHP appears to be metabolized into ETHP by ''Brettanomyces'' over time, this may be one of the mechanisms by which the mousy off-flavor ages out of beer. The possibility of ETHP breakdown is not mentioned in any studies that we know of, although Moulis et al. (2023) reported that for organisms that produced ETHP, there was always a 1:10 ratio between ETHP/ATHP or ETHP/APY, suggesting that this ratio might be governed by the chemistry of the media used and/or the [https://en.wikipedia.org/wiki/Reduction_potential reduction potential] <ref name="Moulis_2023" />. Another unknown is why does ''Brettanomyces'' produce ATHP shortly after kegging and force carbonating a beer that has reached final gravity. The most likely cause is oxygen pick up during the kegging process. Pitching fresh ''Saccharomyces'' at bottling/kegging time and naturally carbonating the beer with sugar has reportedly reduced mousy off-flavor detection, perhaps because ''Saccharomyces'' metabolizes both the oxygen and sugar faster than ''Brettanomyces''.
===Lactic Acid Bacteria===
[[File:THP path bacteria.JPG|thumbnail|right|[http://pubs.acs.org/doi/abs/10.1021/jf020341r Proposed pathway of APY and ATHP by ''L. hilgardii'' by Costello and Henschke (2002).]]]
Heterofermentative [[Lactobacillus]] spp., particularly ''L. hilgardii'' (reclassified as ''Lentilactobacillus hilgardii'') and ''L. brevis''(reclassified as ''Levilactobacillus brevis''), as well as ''Leuconostoc oeni'' <ref name="Grbin_1996" />, can also produce high levels of ATHP, and to a lesser extent APY and ETHP from L-lysine/L-ornithine, ethanol (must be present), and iron. Although many strains of heterofermentative lactic acid bacteria can produce THP, not all do. For example, Costello et al (2008) found that all strains tested of ''L. brevis'' (3 strains tested), ''L. bucherni'' (3 strains tested), and ''L.hilgardii'' (8 strains tested) produced THP, several heterofermentative species did not produce any detectable levels of THP in a grape-based media (one strain each of ''L. fermentum'' and ''L. cellobiosus''). Some strains within a species produce high amounts while others produce low amounts, for example Costell et al. (2008) found that some strains of ''O. oeni'' produced very high amounts between 50-150 µg/L while others produced very little between 5-20 µg/L in a grape-based media <ref name="Costello_2008">[http://onlinelibrary.wiley.com/doi/10.1111/j.1755-0238.2001.tb00205.x/abstract Ability of lactic acid bacteria to produce N-heterocycles causing mousy off-flavour in wine. PETER J. COSTELLO1, TERRY H. LEE1, and PAULA. HENSCHKE. 2008.]</ref>. A strain of ''L. plantarum'' (L11a) was shown to produce relatively low amounts. L-lysine stimulates production of ATHP, and L-ornithine stimulates the production of APY <ref name="Costello">[http://pubs.acs.org/doi/abs/10.1021/jf020341r Mousy Off-Flavor of Wine: Precursors and Biosynthesis of the Causative N-Heterocycles 2-Ethyltetrahydropyridine, 2-Acetyltetrahydropyridine, and 2-Acetyl-1-pyrroline by Lactobacillus hilgardii DSM 20176. Peter J. Costello and Paul A. Henschke. 2002.]</ref><ref>[http://www.ajevonline.org/content/37/2/127.abstract Formation of Substituted Tetrahydropyridines by Species of Brettanomyces and Lactobacillus Isolated from Mousy Wines. Tamila Heresztyn. 1986.]</ref><ref name="Costello_2008" /><ref>Sparrows, Jeff. ''Wild Brews''. Brewers Publications. 2005. Pg. 112.</ref><ref>[https://books.google.com/books?id=tFjsAuo5WocC&pg=PA348&lpg=PA348&dq=lactobacillus+Tetrahydropyridine&source=bl&ots=QUVyoFtIwK&sig=h1cdjB0r1pIRX2Bms8wVA0UiLk4&hl=en&sa=X&ei=4DX_VPz5CsH6oQSAzoGgBA&ved=0CEwQ6AEwCQ#v=onepage&q=lactobacillus%20Tetrahydropyridine&f=false Lahtinen, Ouwehand, Salminen, von Wright. Lactic Acid Bacteria: Microbiological and Functional Aspects, Fourth Edition. Pg 348.]</ref><ref>[http://ajevonline.org/content/37/2/127.short Heresztyn, Tamila. Formation of Substituted Tetrahydropyridines by Species of Brettanomyces and Lactobacillus Isolated from Mousy Wines.]</ref>. Acetaldehyde has a stimulatory effect on ATHP and APY production, but is not required. No studies have been done to show whether or not oxygen plays a role in ATHP/APY production in LAB <ref name="Snowdon"></ref>. Most species of [[Pediococcus]] do not create forms of THP, although a few species do produce relatively small amounts. In particular, these include ''P. pentosaceus'' <ref>[http://www.uniprot.org/uniprot/Q03HT0 UniProt article. Retrieved 3/10/2015.]</ref><ref>[http://www.uniprot.org/uniprot/U5ZF76 UniProt article. Retrieved 3/10/2015.]</ref>, and ''P. clausenii'' <ref>[http://www.uniprot.org/uniprot/G8PEU4 UniProt article. Retrieved 3/10/2015.]</ref>, although one study found no THP in two strains of ''P. pentocaseus'' and only transient/occasional THP production in one out of five strains of ''P. parvulus'' <ref name="Costello" />. ''Oenococcus oeni'' and ''Leuconostoc mesenteroides'' have also been associated with creating ATHP, APY, and ETHP all above threshold amounts. Since only heterofermentative species produce significant amounts of THP, it is thought that its production is linked to the heterolactic pathway, and thus the metabolism of sugars in LAB <ref name="Costello"></ref>. A pathway for APY and ATHP production in ''Lactobacillus hilgardii'' was proposed by Costello and Henschke, which involves the intake of lysine or ornithine, along with ethanol (which is broken down into acetaldehyde) to produce APY and ATHP <ref name="Costello" />. ''Lactobacillus pontis'' has been shown to break down proteins via proteolysis, yielding free amino acids such as ornithine which could serve as precursors to THP formation, and it might be [[Lactobacillus#Foam_Degradation|reasonable to presume]] that other species of ''Lactobacillus'' could also free up ornithine as a precursor to THP <ref name="Adams_2005" />.
===Acetic Acid Bacteria and Mould===
Although research is limited, acetic acid bacteria (''Gluconobacter'' sp. and many strains of ''Acetobacter aceti'') have been shown to produce forms of THP <ref name="Snowdon"></ref>. Mediterranean dried sauses covered in [[Mold|mould]] have been characterized as having APY as a flavor contributor. The source of the APY was identified with a mould that grows on the surface called ''Peniciilium nalgiovense'' <ref name="Adams_2005" />. Moulis et al. (2023) identified several strains of acetic acid bacteria in 32% of selected French wines with mouse taint, but none of the strains produced THP when tested individually in model medium <ref name="Moulis_2023" />.
===Maillard Reactions===
# Does the release of lysine from yeast autolysis when aging on trub increase THP potential (some say it does in wine and cider <ref>[https://www.facebook.com/groups/MilkTheFunk/permalink/1852891514739054/ Tariq Ahmed of Revel Cider. Milk The Funk Facebook thread on THP in wines/ciders aged on lees. 10/16/2017.]</ref>)?
# Are other species of yeast such as wild ''S. cerevisiae'' capable of producing THP <ref>[https://www.facebook.com/groups/MilkTheFunk/permalink/2069944559700414/ Zach Taggart. Milk The Funk Facebook group thread on other yeast species producing THP. 04/24/2018.]</ref>?
# Do sulfites sulphites bind to THP molecules, rendering them unperceivable <ref>[https://www.facebook.com/groups/MilkTheFunk/permalink/2069944559700414/?comment_id=2070023539692516&reply_comment_id=2074259392602264&comment_tracking=%7B%22tn%22%3A%22R%22%7D Otto Forsberg. Milk The Funk Post discussion on THP and sulfites. 04/27/2018.]</ref>?
<nowiki>*</nowiki> Due to the specialized GC/MS equipment needed for measuring forms of THP that most labs do not have, certain answers will be difficult to obtain. Some studies have used alkaline strips as a way to smell the aroma of THP, and while not as precise as the specialized GC/MS lab equipment, could still help further the understanding of THP. These strips were prepared in the following way: knowing that mousy off-flavour has a lingering sensory impact, the technique of alkaline paper strip assessment was adapted from Heresztyn (1986a). Paper strips (Whatman No. 1, 4–5 mm × 50 mm) were prepared by soaking in NaOH (0.1M) and drying overnight at room temperature. The alkaline paper strips were then briefly dipped into cell-free samples (centrifuged) and immediately assessed for the mouse-like odour by sniffing <ref>Private correspondence with Dr.
* [https://www.facebook.com/groups/MilkTheFunk/permalink/1967129246648613/ Milk The Funk thread on THP flavor spikes and other sensory testing approaches.]
* [https://www.facebook.com/groups/MilkTheFunk/permalink/2015071285187742/ Milk The Funk thread on anecdotal experiences of THP forming in beer lines.]
* [https://www.facebook.com/groups/MilkTheFunk/posts/7626497387378409/ Milk The Funk thread reporting an anecdote by Henrik Ventzel that adding some DME and fresh Nottingham yeast to a sour with THP and cleared up THP after 2 months.]
* [https://www.facebook.com/groups/MilkTheFunk/permalink/1034461653248715/ General Milk The Funk Thread on March 10, 2015.]
* [https://www.facebook.com/groups/MilkTheFunk/permalink/1134644959897050/ General Milk The Funk Thread on Aug 25, 2015.]
* [https://www.facebook.com/groups/MilkTheFunk/permalink/1149568535071359/ General Milk The Funk Thread on 09/17/2015.]
* [https://www.facebook.com/groups/MilkTheFunk/permalink/2934892606538934/ MTF thread on THP in natural wine, and increased awareness of THP in wine. as a result.]
* [https://www.facebook.com/groups/MilkTheFunk/permalink/4042481855779998/ MTF thread on removing THP from wine made with low or no sulfitesulphite.]
* [https://www.masterbrewerspodcast.com/237 MBAA Podcast 237: David Fuhrer on bottle conditioning using the German speise method (similar to krausening) reduces THP.]
* [http://www.homebrewtalk.com/f127/brett-strain-production-athp-449852/#post6752813 Homebrewtalk thread started by "ne0t0ky0".]
===External Resources===
* [https://www.youtube.com/watch?v=U-7IDTlg23o THP overview presentation by Richard Preiss at Escarpment Laboratories.]
* [https://punchdrink.com/articles/natural-wine-flaw-mouse/ "The Wine Flaw of Our Times," by John McCarroll.]
==References==