Anyone figured this out? I’ve heard it discussed many times and I hadn’t experienced it until my most recent batch with it. Right out of the keg when it’s cold it’s unreal how diesely it is. It goes away as it warms but it’s unreal. Does anyone know if it’s just batch dependent or if there is a certain process that magnifies these properties? Such as DH in high quantities? It was a Motueka + Nelson pale with higher quantities of Nelson in the DH vs. Motueka. Its an awesome beer once it warms but holy shitballs it’s all diesel out of the keg.
White wine grapes from cooler latitudes are known to be "petrol-y". Since NS was named because it exhibited similar flavors, don't be surprised. What was fermentation like? Any fusels will just exacerbate the problem.
Yeah never thought of it that way but it does have a diesel character that could be intense with a big Dryhop for sure
The short explanation of this is that Nelson is a varietal that is very high in certain volatile thiols/mercaptans. The compound involved with this character is a methylmercaptan/methanethiol. The good news is that thiols tend to have short half-lives so they will age out quickly. If you'd like the longer explanation, I can take a little more time and write it up, as it's not JUST the hop varietal involved, it's also the yeast strain.
S-04 was the yeast of choice for this batch. It was a Motueka/Nelson 4% Pale/ipa/blonde. .5 oz Mosaic FWH 1 oz Motueka @5 1 oz Motueka 2oz Nelson @ FO 4 oz Nelson 1 oz Motueka DH just before TG GP/Carafoam/Carahell Other than the diesel notes it turned out great. Water profile needs a little tweaking but man so I love this hop combo. I’ve used this hop combo a bunch but this is the first time I’ve got that strong diesel aroma. My o2 management and process is a little more dialed now so maybe that has something to do with it.
Don’t meant to hijack, but has anyone else ever accidentally brewed a dill gruit when using a large portion of sorachi ace? I swear, that hop can by so dilly sometimes...
I had an all Sorachi Ace 8.8% double IPA at a brewery a few years ago that was straight dill. Had never tasted anything like it. Had a cool name at least... Ace’s over Eight’s.
So . . . the "deal" with thiols/mercaptans is that some hops have more than others do and some thiols have good flavors and aromas (3MH and 3MHA, and sort of 4MMP) while others do not, like the one mentioned above. Some of those thiols are free and can be liberated easily, but most of them, however, are effectively trapped in aroma and flavor inactive forms via a bond with a sulfurous amino acid like cysteine or glutathoine. In order to liberate those inactive thiols, your yeast strain needs a specific group of enzymes called carbon sulfur lyases. The perform the first step needed in these reactions which is cleavage (hehehe) from the larger molecule. Also useful are powerful AAT enzymes (alcohol acetyl transferases) which all yeast have, but some are more active than others. Specifically the yeast strains that are high ester formers, because that's basically what those enzymes do. If you'd like more information on specific thiols and their hop related sources, I'd be happy to do some digging.
