Mash hopping, are you doing it? - Thiols, chelating metals, aroma, habit.....

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I'm just starting to look into this as I'm 'Thiols Curious' and in this context the only point of mash hopping is to get some of the compounds needed to access thiols in fermentation out into the wort to make them accessible. However it requires certain yeasts to enable this so wont work with normal yeasts. The GM yeasts are not available in this country but WHC have a 'Thiol Producing Liquid Yeast' that has been genetically 'tinkered with' rather than full on modified so is available in the UK. So I'm jus planning a future batch to give this a whirl.

Again you need to choose your hops carefully too as you need a certain type of hop that is 'long lasting', specifically at the mash hop and whirlpool/hopstand and biotransformation dry hop during active fermentation, so their compounds survive through into the fermenter so they can be made available to the yeast. Hops that are not 'long lasting' the compounds will diminish quickly and wont be available for the yeast to work on.

I've tried 'biotransformation' many times and its just not happened, but this now makes sense according to the latest understandings on Thiols.
 

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I guess this is yet another example of the pervasiveness of Hazy's and the quest for in your face aromas and flavours. That thiols are only of importance to juice bombs. I suspect brewers of lager, bitter or porter have known about the subtle layered contribution of thiols for centuries.

I think I'm looking at the long game with mash hopping, looking for the advantages that won't necessarily be apparent with a one off experiment. The Sir Dave Brailsford school of marginal gains.
 
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The GM yeasts are not available in this country but WHC have a 'Thiol Producing Liquid Yeast' that has been genetically 'tinkered with' rather than full on modified so is available in the UK.
Well any kind of "tinkering" without a licence is very very illegal in the UK (and in most of the rest of Europe). My understanding is that WHC claim theirs is a "natural" selection of high-glucosidase yeasts like White Labs' WLP077 Tropicale, but I must admit I don't *quite* trust WHC, without knowing exactly what they've done. To get an idea of how White Labs did it, see this screen of their yeasts - the "best" was WLP300 Hefeweizen, followed by WLP830 (their version of 34/70), WLP400 Belgian Wit, WLP565 Belgian Saison I, WLP519 Stranda Kveik, WLP037 Yorkshire Square, WLP540 Abbey IV (~BE-256?), WLP410 Belgian Wit II and WLP039 (Nottingham).
https://www.whitelabs.com/news-update-detail?id=74
1684183840781.png

Compare that with Lallemand's equivalent, where Wit, their Hefe yeast and Notty all score highly, along with Verdant (1318 derivative) and BRY-97 (Chico family). There does seem to be a bit of a theme emerging.
1684184032458.png

Molitor's Master's thesis funded by Lallemand is interesting for those who want to go into the Lallemand stuff in more depth, he also uses transgenic yeast from Berkeley to explore the effect of really ramping up thiols. Not all thiols are good! Also spare a thought for the brewery whose IPA was used as a sensory standard for "sweaty"....
https://ir.library.oregonstate.edu/concern/graduate_thesis_or_dissertations/0k225k30rThe sensory panel found beers with higher levels of 3M4MPol, 4MMP, and 3MH to be associated with sweaty, vegetal, and overripe fruit, while the beers that were more closely related with 3MHA were associated with floral and tropical in their attributes.
 
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Currently drinking a NE Pale brewed with Hop Unlock yeast, releasing extra flavour potential from a mash addition of Chinook. I have to say it's remarkable. It doesn't matter what they do to NE pales, they're all indistinguishable in taste in the same one dimensional way. Dry hopped with Simcoe, El Dorado and Ekuanot, not seen that combination a thousand times before. Meh.
 
Currently drinking a NE Pale brewed with Hop Unlock yeast, releasing extra flavour potential from a mash addition of Chinook. I have to say it's remarkable. It doesn't matter what they do to NE pales, they're all indistinguishable in taste in the same one dimensional way. Dry hopped with Simcoe, El Dorado and Ekuanot, not seen that combination a thousand times before. Meh.
Agreed there is only so much juice or flavour you can get in the can.
 
I'm currently trialling using freeze dried passionfruit, pineapple, papaya, grape and spinach powders to increase beta-lyase activity as well as cys- glut-3mh & 3mhs precursors in addition to a non GM high beta-lyase activity yeast. Hoping to see improvements with either cascade or saaz mash hopping additions as well. I'm removing the biotransformation hops as the bound thiols from the hopstand hops should be enough alone.
 
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.
 
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.
There are Thiol precursors in both malt and hops so if you do find transferring the trub into your fermenter helps it might just be because you’ve brought more of the raw materials to the table?

In my mind though mash hopping is more about reducing the level of dissolved oxygen in your finished beer to maintain whatever hoppiness you have for longer (reducing oxidation) and generally slowing down the stalling process.
 
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.
The healthier, more vigorous fermentation, giving fruity esters from yeast growth and less subthreshold off flavours, might give the impression of hoppier beer, just through it being a better beer generally.
 

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