A few rambling thoughts and comments on this topic, and other posts so far in the thread:
I have mash hopped but only a couple of times just for fun and I didn't note anything outstanding in the results.
The recent Brew Strong podcast with Scott Janish was interesting - they mentioned that mash hopping might help to reduce metallic flavours in low gravity stouts. I'll be interested to try this as I sometimes detect a bit of metallic-i-ness in my 4.5%-ish porters & stouts. I like that this is a use for mash hopping that isn't really anything to do with hoppy beers.
Interesting that the pomegranate powder mentioned above by
@BasementArtie was also mentioned by Scott.
I've tried WHC Hop Unlock and was *very* unimpressed! I found the resulting beer tasted kind of "muddy" and I was puzzled by what the issue could be. I shared a couple of bottles with forum members though they didn't pick up any specific flaws.
I suspect WHC is an English and strain (possibly Fermentis S33, see below) judging by the low attenuation and the way it flocculates like egg drop soup! Similar to how WY1968 flocculates but I've used that so I don't think its WY1968.
There's a paper by Opstaele et al.
"An exploratory study on the impact of the
yeast strain on hop flavour expressions in
heavily hopped beers: New England IPA". They test a load of Fermentis strains and conclude that S33 & K97 give significantly more biotransformation than US-05.
I've tried both S33 & K97 and neither was a magic hoppy bullet. I wasn't impressed with the flavour of S33 and it was a poor attenuator, hence why I suspect WHC Hop Unlock *might* be the same strain. K97 didn't give me anything radically different to what I normally get from US05 or Lallemand Verdant IPA for example.
*IF* there is a magic hoppy bullet (in my brewery at least!) then it *might* be trub & crud...
Since very early in my brewing career I've let the crud settle to the bottom of the brew kettle for an hour at minimum, then transferred only the clear wort to the FV. My hoppy beers have been ok but always lacklustre, even as I've honed and improved my brewing process from end to end.
Recently I've been experimenting with transfering *ALL* the trub and crud to the FV. I don't have enough data yet to be conclusive but it seems like suddenly my hoppy beers have that extra fruity punch I've been missing. I'm also getting consistently 2-3 SG points more attenuation, and fermenting even quicker (and it's not like they were sluggish before!).
A link
@Sadfield shared recently
(here) might explain the extra attenuation & quicker fermentation, but I'm at a loss as to why trub should promote (I assume) biotransformation.
More data needed but if I can confirm I'm consistently getting improved hop flavour by fermenting with the trub then it puts me in a place to start experimenting with mash hopping to see what more it brings to this kind of beer.
