There are a few things which I don’t compromise on.
One is that I only ever use whole flower hops. I always have used them and I like the flavour you achieve with them. Personally I think the flavour from T90 pellets is coarse. I don’t know why the hops taste different when they are cut up to compact into pellets but they just do to me. I used to think it was because it was all the bits that used to fall out of the machines and get swept up and put into pellets – you know – all the bits that you couldn’t sell otherwise. That would make sense to me. I am assured by what I read that the process of pelletising is a major exercise and done specifically to preserve hop flavors. Good whole flower hops are pulverised on purpose. If this is the case then my hunch is the breaking down of a lot of cell walls must be the reason for the change in hop character. Most of the hop oils that are recognised as properly fruity or aromatic are in the lupulin glands anyway so by cutting up the hops I can see that you would probably mainly just release more herbal grassy compounds.
There is a big disadvantage in using whole flower hops. Because there is a lot more air between each flower, even in a vacuum packet(which is never a perfect vacuum) degradation of hop oils and alpha-acids (which give beer its bitterness during the boil) does occur.In a packet of hop pellets they are crammed so tightly there is far less chance of oxidation. However even in the absence of oxygen hops do degrade. Alpha acids still deteriorate like any complex molecular structure – they can and do break down slowly. This process starts the minute the hop is detached from the bine. Hop farmers make great efforts to get the hops packaged as soon as picked. If you love hoppy beers and all the great array of flavours they bring you have this ball-breaking effort of speed to thank for it.
Which brings me to the point of this blog. Recently I have brewed beer that for me was a little below the hoppiness I expect from the established recipe. So this really got me looking at hop storage and hop degradation. I don’t possess a cold store for hops. The way I choose to prevent hop degradation during storage is to vacpack all hops. In an ideal world you would just buy in the hops you need for the next month or so then all of the trouble keeping hops as fresh as possible is the hop merchants or wholesalers problem. Many breweries probably do exactly that. Unfortunately for a small 2.5bbl artisan small batch diverse brewery like Rammy Craft it is imperative to have a good variety of hops in store (at the last count I have over 40 different varieties). So a packet might last a year or more. After the packet is opened it gets re-vacpacked to preserve the hops. Despite this there appears to be a noticeable reduction in aroma over time.
Surprisingly this is a new phenomena in this brewery, which coincides with buying bigger packets of hops (for economy) than before. So I never had need to research it until now. I wonder how many other brewers have looked into this at all. Most small breweries don’t have their own lab analysis so they need to find some other way of monitoring degradation. My research led me to a recognised index of data called the Hop Storage Index. This is how quickly hops age when left to the elements. This is a measure of alpha-acid degradation principally but it would work as a good starting point to measure ageing of hop aromatics too even if in reality the aromatics go faster. Furthermore it is clear that hops still age in a vacuum packet and even at low temperatures. So it got me wondering about hops supplied by my merchant with a declared AA %. what about older hops I am forced to buy from a previous season. Often all the fresher hops are all reserved to breweries who have pre-ordered the stock. If hops arrive with a 12% AA label when does that pertain to? At the point of packing in say November 2014 or at the point of sale in Nov 2015? There would be a marked difference in AA% by November 15. So I rang my merchant to ask the nitty gritty questions. I was pretty amazed by what I was told:
And I double checked to be absolutely sure that this was exactly what they do.
They test the crop when harvested, label and then don’t ever check the batch again. Their view was that the hops were as good on despatch as the day they were packaged (lmfao).
Lets get this right. If every brewer in the USA – the master of hoppiness – knows hops degrade with time and every craft brewer with space freezes their hops in vac packs to preserve them, how is it a major hop merchant in the UK thinks completely differently? They don’t even freeze their hops in storage – its just cold storage.
So I calculated using Beersmith software (the most popular software for brewing in the world) exactly how much AA% was lost while this vac pack sat in the merchants cold store for 12 months after the crop was harvested.
You might be surprised.
2014 crop bought 12 months later – a typical 12% AA hop would be only 10.5% AA now
2013 crop bought 24 months later – ” ” ” ” ” ” ” ” 9.0% AA now
Its not going to ruin your recipes but it will make a different beer to the beer intended….
Once you get the hops into your brewery it gets worse. The speed of degradation will accelerate if the hops are stored warmer than cold store conditions (5 degrees C), even if vacpacked.
So in a way I see why brewers do use pellets. Anything to keep hold of as much freshness as possible. But I am going to press on with whole flower hops but with greater safeguards in place to ensure the hops I am using are the right hops for the recipe and the hops I thought I was buying! After all the better varieties cost enough and are difficult enough to get hold of.
The other thing I am reminded of is don’t believe everything you are told even by those who you would think would know the truth.
And because of all this when choosing the hops to put in “5” my 5th anniversary Imperial IPA I chose the very freshest American hops only just shipped in from the States. And boy can you smell the difference! It promises to be out of this world.
Oh and about that hop merchant – For the same price as a good bag of mid range UK hops my merchant sold me an old bag of Slovenian hops packaged in 2013 which now only has an AA of 1%. (I was swearing.)
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