oxidising hops

[robsan77]

I've heard a lot about oxidising your aroma hops before use for the best results. Does anyone have any views / protocols for this?

 

[graysalchemy]

Surely that is what we spend all our efforts avoiding with freezing and vacuum packing :wha: :wha:

 

[alanywiseman.]

I have heard of using oxidised hops for belgum beers but that is it.

 

[cnelsonplumber]

I threw a load of different types of oxidised hops away a while ago. These were all ones that I kept in the freezer but bought from a LHBS in clear bags.

The hops had all gone brown which is a sure fire indicator, but most noticably they had almost no aroma. I certainly wouldn't recommend using them in a beer.

Vacuum packed ones are the way to go, I open them carefully use what I need, squeeze the excess air and re-seal with duct tape, then put them back in the freezer. Waste is virtually nil. I think it is to do with the way that the hops are vacuum packed as it reduces the surface area significantly until they are used.

 

[LeedsBrewer]

Out of interest, if the hops are vacuum packed in the silver packs and haven't been opened do they need to be in a freezer or fridge? I was surprised to see them just out on racks in my LHBS.

 

[cnelsonplumber]

Out of interest, if the hops are vacuum packed in the silver packs and haven't been opened do they need to be in a freezer or fridge? I was surprised to see them just out on racks in my LHBS.

Good question. I keep mine in the freezer as they are out of the way

 

[RobWalker]

i'd consider them basically frozen in time if they're vac packed

 

[Aleman]

I've heard a lot about oxidising your aroma hops before use for the best results. Does anyone have any views / protocols for this?

It's a technique worth trying to see if it makes any difference to your beers.

Basically take your aroma hops and rub them hard between your hands to break the lupulin glands . . . if they have been vac packed then they may well have ruptured anyway.

While the boil is underway, put them in a bowl covered with 75C water

Add them to the boil at the appropriate point.

Now for the theory . . . which is in no way my responsibility

In home brewed beers, hop aroma and flavour does seem to diminish with age, probably due to the volatility of the components.

It said that it is the oxidised components of some of the oils in hops that provide the finest flavours and aromas, and that the oxidised components are less volatile and have more stickability in the beer than non-oxidised equivalents. I think that there are two reasons for poor aroma in some home brewed beers:- one is that the hops do not get a chance to oxidise and the second is the habit of home brewers keeping whole hops in the freezer.

Absolutely fresh hops do not display good aroma characteristics; some oxidation is necessary. A little bit of oxidation does occur during the boil, but whole hops stored in the freezer may well have had their resin glands ruptured by the freezing, and thus the essential oils are volatilised before they have a chance to oxidise, so losing lots of potential flavour; this is a similar problem to the one mentioned in the second reference given below regarding hop pellets. Hop pellets have had their glands ruptured by the pelletisation process.

In earlier times commercial brewers used old hops as a deliberate part of their hop charge; this may well have had something to do with flavour. I have seen references from the 1830s of British commercial brewers soaking their hops in water for some hours before using them; this was certainly to do with improved hop character. One assumes that well-oxygenated water would fairly speedily oxidise the hop oils. This is not that different to the process of adding hops to the wort while the boiler is filling, as chiller mentioned; a technique that the Yanks euphemistically call First Wort Hopping. The only way that I can imagine that this works is if it somehow pre-oxidises the hops prior to the boil. It is counter-intuitive otherwise.

Go here: http://www.charlesfaram.co.uk/Technical.htm. And read the Storageability paragraph for a brief mention of oxidation and aroma and the importance of "Controlled Ageing".

Go here: http://www.hopunion.com/education/hopsu ... ml#pellets and read the penultimate paragraph under the heading "Hop Powder Pellets and Hop Pellets" for a bit more on oxidation and aroma and the issue with ruptured glands. Ouch!

 

[soupdragon]

Graham never did follow up on that post, I wonder if he's done any trials?

I had a go some while ago but lost the brew due to not flushing my barrel out properly after cleaning with bleach
Not got around to trying it again but I've got a run of Cascade smashes lined up to experiment with flavour hop additions so may add an extra one. They'll only be 12 ltrs each. Same grist, same yeast, same amount of hops just different late/post boil additions :)

Cheers Tom