I faced a couple of problems at the end of this years hop harvest: what to brew with them and how to store the hops.
I had tried drying my hops last year, but this wasn’t very successful. I had read some articles and forum posts on alternative storage methods and freezing seemed to provide the solution I was after.
I finally settled on brewing a Green Hopped Munich Dunkel – just as the temperature started to get into the perfect cellar range for brewing a lager.
I don’t really grow hops to replace the dried hops that I can readily get from the local homebrew shop or online (as I can’t dry or store them in quantity); nor do I grow multiple varieties to provide both bittering and flavour/aroma hops. I set out to grow hops to get access to green hops to get the freshest and unique hopped quality that only a green hopped beer is supposed to provide.
With that in mind I took the 2kg or so of hops that I had harvested and froze them in 1kg bags. Since I am growing Hallertauer Hersbrucker I needed an opportunity to brew a larger to see how a green hopped larger would work out.
I could have gone for the stock Kellerbier / Munich Helles recipe, but with the need for dark beers increasing with the decreasing temperatures, I thought a Munich Dunkel would be the way to go.
Green Hopped Munich Dunkel Recipe
Boil Size: 30.60 l
Post Boil Volume: 27.60 l
Batch Size (fermenter): 23.00 l
Bottling Volume: 21.00 l
Estimated OG: 1.061 SG
Estimated Color: 42.3 EBC
Estimated IBU: 28.6 IBUs
Brewhouse Efficiency: 74.00 %
Est Mash Efficiency: 85.3 %
Boil Time: 90 Minutes
3.50 kg Pilsner (2 Row) Ger (3.9 EBC) Grain 1 56.9 %
2.15 kg Munich Malt (17.7 EBC) Grain 2 34.9 %
0.25 kg Melanoidin (59.1 EBC) Grain 3 4.1 %
0.14 kg Black Malt (1160.0 EBC) Grain 4 2.3 %
0.11 kg Carafa I (663.9 EBC) Grain 5 1.9 %
80.00 g Saaz [3.30 %] – Boil 60.0 min Hop 6 22.3 IBUs
0.30 tsp Irish Moss (Boil 10.0 mins) Fining 7 –
400.00 g Hallertauer Hersbrucker [0.50 %] – Steep Hop 20 min 5.1 IBUs
18.00 g Hallertau [2.50 %] – Steep/Whirlpool 20 min 1.2 IBUs
1 pkg Saflager Lager (DCL/Fermentis #W-34/70)
Mash Schedule: Single Infusion, Medium Body, Batch Sparge
Total Grain Weight: 6.15 kg
Mash In Add 17.55 l of water at 72.6 C 66.7 C 60 min
Sparge: Batch sparge with 2 steps (4.67l, 16.05l) of 75.6 C water
I managed to hit my mash temperature at dough in bang on. Total mash time was close to the 60 minutes before sparging (twice in my case since my HLT only holds about 18 Ltrs) and I ended up with close to 29 Ltrs in the end with a pre boil gravity of 1.045 meaning I had undershot the expected pre boil gravity of 1.053. I’m starting to suspect that a 90 minutes mash and a better grain crush might be the way to go to get a better efficiency!
Since this was a 90 minutes boil the first 30 minutes are without any hop additions – just watching to avoid any boil overs!
The hops were some ‘old’ Saaz I had left over for the 90 minute addition and for flavour at the end, 18 g of Hersbrucker just to use them up.
Adding the Green Hops
I wanted to preserve as much of the green hop quality without extracting too much vegetal / chlorophyll so I opted for a large whirlpool addition at flame out.
I could not see any green hop additions in the BeerSmith brewing software that, I use so I ‘guestimated’ that since green hops can need anywhere between 4 – 8 times more to get the same Alpha Acids as dried hops – would calculate based on a quarter of a low alpha acid content for my home grown hops to account for this.
It was a large addition, and I was surprised how 400g of green hops wasn’t so ridiculous that it left too much wort back in the kettle after the end of the boil. Having said that, 400g might not have been enough – only time will tell. It certainly seemed to have a hoppy aroma and bitterness when I sampled some of the cooled wort.
I made a small 1 liter starter overnight from some of the cooled wort left in the kettle that didn’t get transferred via the plate chiller and added this back in the morning (I tend to leave the beer overnight with a lager to get it to a cooler temperature than I can presently work too with the plate chiller).
The finished beer is happily fermenting away in the cellar in the 10-12 centigrade range and has produced a nice krausen: not perhaps as thick and pillowy as I get with some of the light Helles largers.
Whilst it is a bit early to tell, the green hops were not too difficult to work with and freezing them seems to be a very viable way of keeping them for a (probably) short period after harvest to extend the period that you can brew green hopped beers from one harvest. The hops cones were still fresh and green, they had not broken down or imparted anything other than the hop qualities you expect. Having said that something is likely to be lost in storing them this way for an extended period and I might well have underplayed or overplayed the green hops in this beer.
But then that is what a green hopped beer is all about: unpredictability and seasonality producing a beer that is a bit outside of the norm.
Perhaps freezing green hops is also a way of extending the time you can get to enjoy these beers outside of what is otherwise a very narrow window of production normally.
Only time will tell.