IPA with methanol aftertaste?

[Marky Mark]

Hi all I'm Mark, novice brewer from NZ. Just tasted a batch of IPA made from mangrove jacks pouch with added NZ hops. Looks great, getting citrus/ grapefruit taste as per IPA, but a definite initial methanol/gasoline fumes? hit on initial taste. Fermentation temp was kept constant at 20-23degrees Celsius throughout . What have I done wrong?

 

[azmark]

23c ambient temp could be quite warm. The internal temp of the beer could be quite a bit higher. Also, did you treat your water for chlorine?

 

[Marky Mark]

Thanks for that, chlorine could be a problem. Our town had an outbreak of campylobacter a year ago and have since chlorinated drinking water heavily. Should I preboil all water for my brew?

 

[Yooper]

23C is way too hot for most ale yeast, if it was room temperature. I've personally seen active fermentations be 10 degrees F above ambient temperatures, so during fermentation you could have had temperatures as high as 28 or 29C with the beer inside the fermenter.

That would cause higher-chain alcohols, called "fusels" which give headaches and smell very alcohol- like.

Chlorine causes "phenol" flavors- like clove or even wet bandaids, but generally not the "hot" flavors.

You should always treat your brewing water for chlorine- 1/2 of a campden tablet, crushed and dissolved in a little water, treats 10 gallons of brewing water instantly to get rid of chlorine, or the more stable form of chlorine often used by water companies, chloramine.