AG56 - Freeze Concentrated Eisbock

[strange-steve]

This is tomorrow's brewday, something a bit different. Bock isn't a style I'm too familiar with, but essentially it's a strong, malty, German lager. This is going to be an eisbock, which is a dopplebock which is freeze concentrated after fermentation to increase the alcohol content and enhance flavours. I've never tasted one, but I've heard a good eisbock is about the finest beer you can find. I'm also going to do a single decoction mash to try to enhance the malt flavours. It's been a couple of years since I've done a decoction mash so it could be a disaster.

This has been on my brew list for a long time and I've just got the brew fridge up and running after moving house so decided it was time to get this done. This will be another long term beer, about 3 months in the FVs then 6-12 months in the bottle before it's ready.

AG 56 - Eisbock

Recipe Specs
----------------
Batch Size (L): 20
Total Grain (kg): 9.08
Total Hops (g): 30
Original Gravity (OG): 1.092
Final Gravity (FG): 1.023
Alcohol by Volume (ABV): 11.3% (after freeze concentration)
Colour (SRM): 12
Bitterness (IBU): 27
Brewhouse Efficiency (%): 65
Boil Time (Minutes): 60

Grain Bill
----------------
5.0 kg Pilsner (55%)
3.5 kg Vienna (38%)
250 g Caramunich II (3%)
180 g Acidulated Malt (2%)
150 g Caramunich III (2%)

Hop Bill
----------------
15.0 g Magnum Pellet (12.5% AA) @ 60 Minutes
15.0 g Hallertau Mittlefrueh Pellet (6.3% AA) @ 30 Minutes

Water Treatment
----------------
RO water with 0.2g/L calcium chloride

Mash Schedule
----------------
Mash in 55° for 15 mins
68° for 45 mins then remove 6.6L of mash for decoction
Bring it to the boil and simmer gently for 30 mins
Add back to mash aiming for 75° and hold for 15 mins

Notes
----------------
Ferment at 10°C with Saflager W-34/70.
After fermentation is complete, lager at 0°c for 4 weeks.
Then rack to secondary and set fermentation fridge to -15°c, remove 20% of volume as ice when it begins to freeze.
Lager at 0°c for 4 more weeks.
Reseed with US-05 when bottling.

Pics to follow...

 

[Sbond10]

Wow that sounds amazing

 

[YeastFace]

Sounds like a fantastic challenge, good luck!

Think I've only tried Schneider Weisse Aventinus, probably the benchmark of the style. A wonderful beer.

 

[IainM]

You don't go for the easy ones do you!

 

[serum]

Now this sounds awesome!

 

[strange-steve]

First things first, the essential brewday morning coffee

The Grainfather instructions say it can take up to 9kg of grain, this is what that looks like. I actually held back a couple of litres of mash water and as you can see it's still to the brim.

The decoction.

Starter which has been going since yesterday.

 

[Leon103]

Sounds amazing. WIll a fridge go down to -15???

 

[strange-steve]

Sounds amazing. WIll a fridge go down to -15???

I've bypassed the thermostat but I'm still not sure tbh. It doesn't actually need to get that cold though, -4° is cold enough to freeze a 10% abv solution apparently.

 

[peebee]

I'm surprised the moderators have let this thread run?

Freeze concentrating your beer (even for home use) requires a distillers license from HM Revenue and Customs. Boring isn't it.

 

[strange-steve]

I'm surprised the moderators have let this thread run?

Freeze concentrating your beer (even for home use) requires a distillers license from HM Revenue and Customs. Boring isn't it.

This has been debated for years on the various brewing fora, but someone on JBK contacted Brewdog to ask if they had to get a distillers licence to brew their eisbock and they said no, it still counts as beer (see here).

 

[Alside101]

This has been debated for years on the various brewing fora, but someone on JBK contacted Brewdog to ask if they had to get a distillers licence to brew their eisbock and they said no, it still counts as beer (see here).

didnt thay do it in a icecream warehouse the first time? cant see them having a licence

 

[strange-steve]

It's in the fridge now cooling to 10° before I pitch. Hit OG spot on but was a little under volume, so got 19L @ 1.092.

 

[serum]

It's in the fridge now cooling to 10° before I pitch. Hit OG spot on but was a little under volume, so got 19L @ 1.092.

You won't be getting through 19L of that in a hurry!

 

[BeerCat]

I'm surprised the moderators have let this thread run?

Freeze concentrating your beer (even for home use) requires a distillers license from HM Revenue and Customs. Boring isn't it.

I dont think that is correct. There is a big secue video where he goes to brewdog and they discuss this very thing.

 

[strange-steve]

You won't be getting through 19L of that in a hurry!

You're not wrong, this'll definitely be a sipper. The jacking will concentrate that down to 15L which is equivalent to an OG of 1.117 :shock:

 

[peebee]

This has been debated for years on the various brewing fora, but someone on JBK contacted Brewdog to ask if they had to get a distillers licence to brew their eisbock and they said no, it still counts as beer (see here).

Thanks for that. I had just assumed Brewdog was licenced. This caper has passed me by somewhat.

 

[Badseed1974]

I've just done this by accident!

My cold crash got a little too cold and froze 2-3 litres (guessing here) and I'd already bottled 20 before I noticed!

I let the rest thaw out and bottled it later, the first batch is noticeably darker, nice to get 2 different beers out of it even if I didn't mean it :)

 

[Cwrw666]

Maybe you don't need a licence because you're not extracting alcohol, you're just extracting water.

 

[strange-steve]

Took a gravity reading this morning, one week in and it's down to 1.046 and still going strong, so well on track. There's a rather unpleasant sulphur smell coming from it, which isn't unusual for a lager, but the flavours seem pretty good.

 

[MyQul]

I'm surprised the moderators have let this thread run?

Freeze concentrating your beer (even for home use) requires a distillers license from HM Revenue and Customs. Boring isn't it.

Yup, we've had this discussion before. Freeze distilling isnt true distilling (and not against the law to do so) so it's ok as far as we're concerned