Tetrahydropyridine: Difference between revisions
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Tetrahydropyridine (THP) and related compounds can give an "off flavor" that tastes grainy like Cheerios® or Cap'n Crunch® cereal, or at high levels sometimes "mousy" (like rodent urine).<ref>[https://www.lambic.info/Tetrahydropyridines "Tetrahydropyridines."] Lambic.info wiki. Accessed May 2020.</ref> However, not everyone can taste these compounds, and some people may enjoy a low amount of THP flavor.<ref>[https://www.homebrewtalk.com/threads/thp-tetrahydropyridines.661096/ "THP (Tetrahydropyridines)"] Forum thread. HomeBrewTalk. January 2019.</ref> | Tetrahydropyridine (THP) and related compounds can give an "off flavor" that tastes grainy like Cheerios® or Cap'n Crunch® cereal, or at high levels sometimes "mousy" (like rodent urine).<ref>[https://www.lambic.info/Tetrahydropyridines "Tetrahydropyridines."] Lambic.info wiki. Accessed May 2020.</ref> However, not everyone can taste these compounds, and some people may enjoy a low amount of THP flavor.<ref>[https://www.homebrewtalk.com/threads/thp-tetrahydropyridines.661096/ "THP (Tetrahydropyridines)"] Forum thread. HomeBrewTalk. January 2019.</ref> | ||
THP is | THP is produced by "wild" microbes like ''[[Brettanomyces]]'', lactic acid bacteria such as ''[[Lactobacillus]]'', and [[acetic acid bacteria]]. It most often forms around the time of packaging, when THP production is stimulated by the presence of oxygen +/- fermentable sugar.<ref>Tyers, B. [https://www.goodbeerhunting.com/blog/2018/12/18/cereal-killer-why-thp-is-bad-for-beer-and-what-you-can-do-about-it "Cereal Killer — Why THP is Bad for Beer and What You Can Do About It."] Good Beer Hunting. December 2018.</ref> THP is a significant concern in [[sour beer]], where these microbes are commonplace, but it may also occur in [[wine]], [[cider]], [[mead]], etc. if wild microbes are present. | ||
Best strategies to avoid THP: | Best strategies to avoid THP: | ||
Revision as of 15:53, 1 May 2020
Tetrahydropyridine (THP) and related compounds can give an "off flavor" that tastes grainy like Cheerios® or Cap'n Crunch® cereal, or at high levels sometimes "mousy" (like rodent urine).[1] However, not everyone can taste these compounds, and some people may enjoy a low amount of THP flavor.[2]
THP is produced by "wild" microbes like Brettanomyces, lactic acid bacteria such as Lactobacillus, and acetic acid bacteria. It most often forms around the time of packaging, when THP production is stimulated by the presence of oxygen +/- fermentable sugar.[3] THP is a significant concern in sour beer, where these microbes are commonplace, but it may also occur in wine, cider, mead, etc. if wild microbes are present.
Best strategies to avoid THP:
- Avoid excessive oxygen exposure prior to packaging and during packaging. (For beer, see low oxygen brewing cold-side methods)
- For carbonated beverages: Naturally carbonate rather than force carbonate, and add yeast from an acid tolerance starter at the time of packaging.
- Passivation of all stainless steel parts that come into contact with the wort, beer, wine, etc. would theoretically be helpful, along with the use of RO water in brewing. These measures help limit iron, which is required for THP production.[4]
- In wine, proper usage of sulfite should inhibit the wild microbes that would otherwise produce THP.
If THP forms, it typically ages out over a period of months, but it may take longer.
See also
Visit the Milk the Funk wiki for more information about THP.
References
- ↑ "Tetrahydropyridines." Lambic.info wiki. Accessed May 2020.
- ↑ "THP (Tetrahydropyridines)" Forum thread. HomeBrewTalk. January 2019.
- ↑ Tyers, B. "Cereal Killer — Why THP is Bad for Beer and What You Can Do About It." Good Beer Hunting. December 2018.
- ↑ Snowdon, EM., et al. "Mousy Off-Flavor: A Review." J. Agric. Food Chem, vol. 54, no. 18, 2006, pp. 6465-6474.