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

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Sadfield

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A quick forum search reveals that discussions about mash hopping are rare and many are relatively old, with the odd fleeting reference in recent threads about new yeast products, or hazy oxidation. So, perhaps it's time for fresh discussion.

A better than expected harvest of Prima Donna (First Gold) hops has had me thinking of ways to use them, with the mash being a typical hop free place. Being vaguely aware of mash hopping aiding oxidative stability and recent discussions of biotransformation and thiol precursors, I decided to use a mash hop addition of Prima Donna in an West Coast IPA using Chinook, Citra Simcoe and verdant yeast. It could well be the flame out addition and yeast, but the gravity sample certainly has an aromatic punch that has me tempted not to dry hop. Could it be the mash addition?

I'm also intrigued by the notion of adding home grown hops to the mash as way of adding terroir in an unobtrusive way. Using up the years crop without brewing exclusively First Gold beers.

Are any of you mash hopping for these or any other reasons? Any good information to share?
 
Yes, I mash hop mostly to complex metal ions and reduce the level of these making it to the final product because metal ions are pro-oxidative. I tend to only do this though for very highly hopped beers.

I also have a suspicion that lemon grass finely chopped and added to the fermenter with the wort and yeast does a great job of preserving beer through it’s anti-oxidant qualities. I was at the time looking to use lemon grass as a rich source of Thiol precursors. The original intent didn’t yield the results I hoped for but that highly hopped beer did very well in a forum comp after about 8 months if I remember correctly.

Your mash hopping addition will have added precursors but I always got more from the hopstand.
 
You are right the idea is only discussed far and few between. I have bags of leaf hops in the freezer that I need to use up. So I will keep and eye on this discussion.

The few places I have heard about it didn't seem to contribute much.
 
When I tried it a few years ago, I didn't get what the fuss was about. Little or no gain. And to be honest lodo/minimizing oxidation /extended preservation etc etc have never had a problem. I brew to drink, not to look at. Plus I have some 5 year old bottles that are just starting to go over. That'll do.
 
…the gravity sample certainly has an aromatic punch that has me tempted not to dry hop. Could it be the mash addition?


I just searched for mash hopping against my own name to remind myself and found posts where I noted that dry hopping actually reduces thiols (they are absorbed by the vegetative material) and also found an experiment I did where I made a batch of beer that ONLY used mash hopping to see how aroma, flavour, and bitterness followed through. In my one trial I’m afraid flavour and aroma didn’t contribute much, bitterness was just as expected (about 1/8 - 1/10 of the IBUs from boiling the same quantity for the same time).
 
I made a batch of beer that ONLY used mash hopping to see how aroma, flavour, and bitterness followed through.
Can you remember which yeast you used. It does appear to be related to β-lyase. This is partly my reason for a reboot as I wonder if many of the older threads and posts like the one above from @MashBag relate to not using a yeast that will liberate thiol precursors.
 
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Can you remember which yeast you used. It does appear to be related to β-lyase. This is partly my reason for a reboot as I wonder if many of the older threads and posts like the one above from @MashBag relate to not using a yeast that will liberate thiol precursors.
I used a blend of Verdant and BRY-97 as each of these is good at the two main biotransformation processes. This post, and the ones above and below may apply…

This last slide is interesting because it’s published information from Lallemand on the amount of activity from these two enzymes across a range of yeasts. Now what if you fermented using a blend of BRY-97 and Verdant? 🤔

View attachment 50255
 
Chelating metals is a new one for me... Anyone got a 'for dummies' explanation of what it is and why I might want to do it?
Yes, it’s bonding molecules to metal ions. In the normal course of events metal ions from the brewing process bind with oxygen that then ends up in the finished beer. If you can bind something else to those metal ions first you have less oxygen in your finished beer and it stays fresh longer.
 

Generation of ROS​

Many of the reactions recognised to cause staling can be attributed to the action of reactive oxygen species (ROS) in beer. Molecular oxygen is relatively unreactive in its ground state and so must first be activated to form the ROS responsible for these reactions. This activation is catalysed by the transition metals Iron and Copper and is an example of a Redox reaction. The amount of ROS generated is dependent on the level of oxygen in the beer, the storage temperature, as well as the availability of Iron and Copper ions to catalyse the reaction (Vanderhaegen, 2006).
As @Hazelwood Brewery said, the idea is to bind the copper and iron to hop acids instead of oxygen. My understanding is this is best done at higher pH, which in brewing terms is at the start of mashing.
 
@Hazelwood Brewery did you happen to notice a change in the bitterness character from mash hopping?
Sorry @Pennine I can’t now remember. The degree of bitterness was as expected but I can’t remember, and didn’t note anywhere, whether the character of that bitterness was any different to the bitterness from regular boiling.
 
As @Hazelwood Brewery said, the idea is to bind the copper and iron to hop acids instead of oxygen. My understanding is this is best done at higher pH, which in brewing terms is at the start of mashing.
That’s right. You use high alpha-acid hops (for best effect) at 1-2g/litre. Make sure you use leaf hops that you can remove at the end of the mash, pellet hops disintegrate and end up in the boil where they can add bitterness.
 
I tried mash-hopping a few times without any notable differences in the finished beer. First Wort Hopping does make a difference, at least for me. Another down side to mash hopping is dumping the mash tun when the lauter and sparge is done. Hops are a bit rough on dogs who tend to get into the mash tailings so I wind up throwing the spent grist into the garbage instead of my mulch bed.
 
Did first mash hopping with Saaz then
Other hops at first wort, flameout, whirlpool'nd dry hop.
Listened to a good podcast on craft beer and brewing that explains the rationale and which hops to use.
I couldn't access a genetic thiol yeast or phantasm so went with verdant and an expressive kveik.
I do think it came out the best of my 3 brewed hazies.
 
Did first mash hopping with Saaz then
Other hops at first wort, flameout, whirlpool'nd dry hop.
Listened to a good podcast on craft beer and brewing that explains the rationale and which hops to use.
I couldn't access a genetic thiol yeast or phantasm so went with verdant and an expressive kveik.
I do think it came out the best of my 3 brewed hazies.

Don't suppose you happen to have a link to that podcast?
 
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