Dorst
Well-Known Member
It all started with a topic on Reddit about Japanese lagers... The topic starter linked to a page and Youtube video with some guys making an absolute mess of a Japanes lager. I never brewed a Japanese lager before but I had to imagine I could do better. It kickstarted me into drafting my own recipe.
I remembered from reading Mark Dredge's A brief history of Lager (Goodreads link) that Japanese lagers use an enzyme that ferments down the beer further than other lagers. Asahi even markets itself a super dry. After some research I decided that the most likely enzyme to use is glucoamylase - most commonly used in distilling. The satchet was pretty cheap and costed about the same as dry yeast.
To start drafting I took Asahi super dry as my target beer: 5 percent ABV, IBU 20, SRM 4.
Base assumptions:
- Malt base is rougly 1/3 rice and 2/3 barley (pilsner) as is customary for Japanese lager. Colour is slightly below Asahi spec, so I could use a darker base pilsner or add some grams of melanoidin to compensate for colour. I decided to keep it nice and pale
- Use a neutral yeast (W34/70 is a good choice) x 2pkgs
- Use Sorachi ace for 20 IBU (60 and 10 minute additions). Sorachi Ace hops were grown for Sapporo beer and not Asahi but make an excellent choice for a Japenese lager I feel
So I first drafted a recipe without enzyme usage and trying to maximise fermentability to get a base recipe:
Stats
Original Gravity: 1.043
Final Gravity (Adv): 1.004
IBU (Tinseth): 20
BU/GU: 0.46
Colour: 5.5 EBC
Mash
Temperature — 60 °C — 30 min
Temperature — 70 °C — 30 min
Temperature — 78 °C — 1 min
Malts (4.2 kg)
2.8 kg (66.7%) — Weyermann Barke Pilsner — Grain — 3.5 EBC
1.4 kg (33.3%) — Rice, Flaked — Grain — 2 EBC
Hops (23 g)
5 g (9 IBU) — Sorachi Ace 13% — Boil — 60 min
18 g (11 IBU) — Sorachi Ace 13% — Boil — 10 min
Yeast
2 pkg — Fermentis W-34/70 Saflager Lager 83%
So the next step was to guess what adding the enzyme was going to do to this beer. My assumption was that it would simply make the wort more fermentable and potentially take the beer all the way down to 1.000 FG. That would take the beer from 5.1 ABV to 5.6 ABV. These are quite small margins in my opinion so I decided to not alter the recipe and only make a small adjustment to the mash to accomodate the enzyme.
I added 6 grams (half the satchet) of glucoamylase to the mash. On the instructions it said that you should leave the mash between the optimal temperature range (50C to 60C) for an hour. I decided to alter my mash schedule as follows:
Mash
Temperature — 50 °C — 15 min
Temperature — 60 °C — 45 min
Temperature — 70 °C — 30 min
Temperature — 78 °C — 1 min
Last Sunday I got to brew this bad boy. It was a pretty relaxed brewday with a longer than ussual mash. Luckily I have a Braumeister brew kettle that allows me to program mashing steps. I tend to get quite reliable results so I dropped measurement after mash and went straight to boil. When I cooled down the wort I was in for a bit of a surprise; the wort ended up at 1.050 instead of 1.043.
The glucoamylase apparently pushed up my normal 76 percent efficiency to a pretty amazing 86 percent efficiency. A bit of an oversight on my end but it makes sense looking back. It's only a good experiment when you learn something right? ;-)
If the beer is indeed as fermentable as I think it is (fermenting down to 1.000 FG) it will end up 0,9 percent higher ABV (6,5 percent). I will keep a close eye on how far down this beer will ferment and if my assumptions on this end are correct.
I'm quite excited to see how this ends up. Does the glucoamylase have impact on the flavour of the beer? Perhaps some other unknown effects? Did I even choose the right enzyme for the job? I fairly confident that I'm on the right track and will just need to tweak down the recipe for my next brew to hit the targeted 5 percent ABV.
I remembered from reading Mark Dredge's A brief history of Lager (Goodreads link) that Japanese lagers use an enzyme that ferments down the beer further than other lagers. Asahi even markets itself a super dry. After some research I decided that the most likely enzyme to use is glucoamylase - most commonly used in distilling. The satchet was pretty cheap and costed about the same as dry yeast.
To start drafting I took Asahi super dry as my target beer: 5 percent ABV, IBU 20, SRM 4.
Base assumptions:
- Malt base is rougly 1/3 rice and 2/3 barley (pilsner) as is customary for Japanese lager. Colour is slightly below Asahi spec, so I could use a darker base pilsner or add some grams of melanoidin to compensate for colour. I decided to keep it nice and pale
- Use a neutral yeast (W34/70 is a good choice) x 2pkgs
- Use Sorachi ace for 20 IBU (60 and 10 minute additions). Sorachi Ace hops were grown for Sapporo beer and not Asahi but make an excellent choice for a Japenese lager I feel
So I first drafted a recipe without enzyme usage and trying to maximise fermentability to get a base recipe:
Stats
Original Gravity: 1.043
Final Gravity (Adv): 1.004
IBU (Tinseth): 20
BU/GU: 0.46
Colour: 5.5 EBC
Mash
Temperature — 60 °C — 30 min
Temperature — 70 °C — 30 min
Temperature — 78 °C — 1 min
Malts (4.2 kg)
2.8 kg (66.7%) — Weyermann Barke Pilsner — Grain — 3.5 EBC
1.4 kg (33.3%) — Rice, Flaked — Grain — 2 EBC
Hops (23 g)
5 g (9 IBU) — Sorachi Ace 13% — Boil — 60 min
18 g (11 IBU) — Sorachi Ace 13% — Boil — 10 min
Yeast
2 pkg — Fermentis W-34/70 Saflager Lager 83%
So the next step was to guess what adding the enzyme was going to do to this beer. My assumption was that it would simply make the wort more fermentable and potentially take the beer all the way down to 1.000 FG. That would take the beer from 5.1 ABV to 5.6 ABV. These are quite small margins in my opinion so I decided to not alter the recipe and only make a small adjustment to the mash to accomodate the enzyme.
I added 6 grams (half the satchet) of glucoamylase to the mash. On the instructions it said that you should leave the mash between the optimal temperature range (50C to 60C) for an hour. I decided to alter my mash schedule as follows:
Mash
Temperature — 50 °C — 15 min
Temperature — 60 °C — 45 min
Temperature — 70 °C — 30 min
Temperature — 78 °C — 1 min
Last Sunday I got to brew this bad boy. It was a pretty relaxed brewday with a longer than ussual mash. Luckily I have a Braumeister brew kettle that allows me to program mashing steps. I tend to get quite reliable results so I dropped measurement after mash and went straight to boil. When I cooled down the wort I was in for a bit of a surprise; the wort ended up at 1.050 instead of 1.043.
The glucoamylase apparently pushed up my normal 76 percent efficiency to a pretty amazing 86 percent efficiency. A bit of an oversight on my end but it makes sense looking back. It's only a good experiment when you learn something right? ;-)
If the beer is indeed as fermentable as I think it is (fermenting down to 1.000 FG) it will end up 0,9 percent higher ABV (6,5 percent). I will keep a close eye on how far down this beer will ferment and if my assumptions on this end are correct.
I'm quite excited to see how this ends up. Does the glucoamylase have impact on the flavour of the beer? Perhaps some other unknown effects? Did I even choose the right enzyme for the job? I fairly confident that I'm on the right track and will just need to tweak down the recipe for my next brew to hit the targeted 5 percent ABV.
