I have almost no sensitivity to diacetyl but I am crazy sensitive to clove and similar spiciness. I have 20 gallons of German lager made for a Christmas party that I will do a D rest on this weekend just for safety sake, but I won’t be able to tell if it gets rid of it or just reduces it. I was at a club meeting at a regional brewpub and an accomplished judge told me to try a beer to be able to taste what diacetyl is and I told him that I perceived a little slickness on the tongue, but no discernible taste issue. He said I have much to learn, so I am signed up for his BJCP tasting class this winter. Call me palate deprived, but willing to learn.
A high % of the population is blind to diacetyl. That is due to genetics and you can’t learn to taste diaceyl if you can’t, it is like being color blind to some colors. My sensitivity is medium high to high. I have to use the slickness test for levels sensitive people call out Diacetyl! Sam Smiths beers, I get it. Ringwood breweries, I usually get it.
I heard of a few guys that either get it on the end of their nose, or as slickness or as a soapiness. Hopefully I will fall in there somewhere as I had a lager recently that a couple guys said was not great and as it was a step up lager, to just get enough yeast to do a full batch to pitch into, I wasn’t too worried, but I suspected diacetyl issues. Nobody could give me a good descriptor for the flaw, so I don’t know what the issue was for sure,but I suspect diacetyl. I tried my best to tell what they tasted, but at this point I guess I must admit my blind spot…
I should I say the % is around 20. I judge fairly often with a National Lever that is blind to diacetyl. We make a great pair! Another National Level judge is hyper sensitive to diacetyl, but readily admits he is blind to DMS.
We all have our palates and have to live/adapt to them.