Light Struck

Comments from NHC judges regarding my Kolsch. Both stated it to have a light struck aroma that dissipated as it warmed. Is this yeast related?  I know I’ve been having oxidation issues. I believe I have this issue figured out. I wondered because it didn’t see any type of light. Pitched plenty of healthy Giga021 yeast.  Controlled the temps, and all aspects I thought. Scored 37.5, 36 and 39. Just wondering…

What is the aroma you get from “light struck” beer?  I always thought it was what folks called “skunked”, but I didn’t think that character dissipated as it’s warmed.

In my experience, beer is either skunked (light struck) or not. Pure binary, no going back.

Maybe there was a sulfurous quality that dissipated? I could possibly see that being mistaken for a skunk stink.

Yeah, I have never had skunk dissipate as the beer warmed.

Much like sulfur, I find minor skunking can dissipate.  I’ve made a farty beer before (many years ago) where I recall telling my friends “pour it into your glass, then walk away for 5 minutes, then come back and enjoy”.  Mercaptan compounds are of course volatile so it makes sense to me that in some cases you could do the same thing to a slightly skunked beer – pour, walk away, come back and enjoy.  Or, just embrace the skunk.

I’m a huge fan of Heineken, but only from a can/draft.

Skunked beer is awful.

The mercaptans that are responsible for skunking are highly volatile. Perhaps a small amount could dissipate.
On a similar note, I’ve never worried about light exposure during the brewing process. And mercaptans generated should blow off during fermentation

I seem to remember that mercaptans can only be produced after fermentation…though perhaps it was boiling?

I’ve never worried about it during the boil, and my wort is often in direct sunlight. No skunk.

The boil would drive it off.  I’m sure if you left a glass carboy fermenting in broad daylight, you could pick up some skunk.  However, the action of CO2 production would likely scrub most of it out until towards the end of fermentation.  In similar fashion, I think CO2 from fizz can drive things out when poured into a glass or pitcher.  But if that same glass or pitcher is left in the sunlight, skunk city.

Riboflavin is involved in the skunking mechanism. It is a product of fermentation.

Hey, a few years back I bottled in the garage, and some sun was shining in through the window in the pedestrian door. Not a lot of time or sun. The sheets said light struck. The control bottle confirmed it.

My primary racking/bottling space has direct sunlight for most of the day…I rack/bottle after dark.

I now cover the door’s window if bottling during the day.

THIS^^^^^^^

I’ll have to look that up. I know it didn’t see light. I figured it was yeast related. How, I’ll look that up, thanks. Jeff actually judged it in Indy. [emoji106]

I remebered getting one there. Sorry it was yours, seemed good othwise from what I recall.

It wasn’t terrible, not a big deal. Finished at 37.5,  so not horrendous. If you don’t want feedback, don’t enter right?  I didn’t pick that flavor up, and both of you did. I guess I need to learn more on that end to know what is wrong with my beers. Now to figure how to correct it.

Could something have happening in handling/transit?

About 5-6 years ago I got a double IPA through to the final round judging of NHC. Comments came back that it was skunked even though it never saw any light whatsoever. Brewed in a garage, fermented in a fridge, then kegged.
I am guessing that the judges were picking up on some catty aromas from the dank"ish" hops I used.

Some will say this for sulfur perception. I like to think I have sulfur compounds categorized, and can tell skunk from cabbage from burnt match from rotten egg, from catty. Some can’t.

I’m with Dave.  I’ve also had many cases where some very light skunkiness up front would dissipate, but it was always faint to begin with.  I find sulphury notes to dissipate quite often, while esters, oxidation, and phenolics tend to intensify over time.

I always make it a point to revisit aroma after evaluating flavor and before recording overall impression to check out whether the aromas lingered, dissipated, or intensified.  I’ll often add a note on what changed (or didn’t).

<Hint to prospective BJCP examinees -  GRADERS LOVE TO SEE THIS ON AN EXAM (and on competition score sheets)>