What does genetics have to do with IPAs?

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ryanmetcalf
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What does genetics have to do with IPAs?

#1 Post by ryanmetcalf » Sun Jun 28, 2020 12:20 pm

https://homebrewacademy.com/genetics-ipa/
Our BJCP study group was holding one of its bi-weekly meetings. Studying for the exam means refining your tasting abilities. Ideally, you and the other judges are in agreement on what you smell and taste in a beer. The first thing you do after a round of scoring is compare your score to that of your cohorts and hope you’re not too far off.

Yet this particular night, we were about to prove that no matter how hard we studied, mother nature has ensured that we’ll never taste things exactly the same.
Possession of TAS2R38, aka the PTC gene, codes for a bitter taste receptor on the tongue. In beer-drinker language, if you have the tasting form of this gene then you can taste the chemical known as PTC, which tastes bitter.

You can determine whether or not you have the gene by using PTC paper. Depending on the person, the paper is revoltingly bitter, slightly bitter, or tasteless.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2721271/
Individual humans differ in bitter taste perception, and some of this variation has a genetic component (140). Human TAS2R genes have substantial diversity of coding sequence (87, 122, 161, 167), which suggests that TAS2R polymorphisms may be responsible for the genetic component of individual differences in bitter taste.

However, this relationship has been demonstrated only for one gene, TAS2R38. It is located on chromosome 7, where linkages for PTC and PROP taste sensitivity have been detected (40, 41, 50, 135, 139). Allelic variants of TAS2R38 explain more than 50% of phenotypical variation in PTC sensitivity (88) and are also associated with human perception of PROP bitterness
https://www.craftbeer.com/craft-beer-mu ... hoppy-beer
So there you have it, IPA-haters: It’s not your fault. Dr. Garneau said that humans were never supposed to like bitter beer in the first place, and we can’t do anything about our genes, right?
Not so fast …
If humans are naturally averse to bitter tastes, why are coffee, tea and brussels sprouts so popular? And why are so many people crazy about hops in craft beer?
The answer Garneau revealed is that the environment is to blame. Outside influences can teach your brain to override its genetic predilection and aversions.
https://www.huffpost.com/entry/bitter-b ... 0e27428adb

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Re: What does genetics have to do with IPAs?

#2 Post by ryanmetcalf » Sun Jun 28, 2020 12:36 pm

Has anyone ever tested out the PTC paper? Has anyone tried any of the home DNA tests that offer analysis of TAS2R38 gene? I did 23andMe years ago, and they report that I have the GC variant, but I've not had issues with IPAs in general, though I did not start my craft beer journey with them. Reading seems to indicate exposure can easily override bitterness aversion. I am curious to give the PTC papers a try though.

Image

https://www.bonappetit.com/entertaining ... nges-aging
"The big predictor of whether someone will like something like bitter melon or hoppy beer isn't their sensitivity to bitterness," Marcia Pelchat, a sensory psychologist at the Monell Chemical Senses Center. "It's their exposure to it, their motivation, their interest. It's all cultural stuff."
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4106902/
Age-Related Differences in Bitter Taste and Efficacy of Bitter Blockers
The blockers reduced bitterness in 7 of 10 bitter-blocker combinations for adults but only 3 of 10 for children, suggesting that efficacy depends on age and is also specific to each bitter-blocker combination. Only the bitterness of urea was reduced by both blockers in both age groups, whereas the bitterness of PROP was not reduced by either blocker in either age group regardless of TAS2R38 genotype.

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