Crop, Bock & Decoct

Smoked Bock Homebrew Recipe

After this blog I thought it might be a good idea to do a follow up once I had the time to plan and use some of the yeast I’d stored.

Following a truly life changing moment, the first time I tried Schlenkerla Helles  thanks to Phil Lowry and Beer Merchants (link to my clone recipe for this beer here) I’ve become even more obsessed with smoked beers leading me to brew a tribute to Schlenkerla Helles with Ayinger’s yeast strain.

Schlenkerla Beers

Some of my favourite German Smoked Beers from Schlenkerla in Bamberg

Not wanting to lose that strain (buy it again) I decided to crop and store it on the 23/9 last year, I was expecting to use it within a couple of weeks…unfortunately four months went by with other demands taking precedence and finally I got round to wanting to brew a lager again.

I wasn’t really keen on leaving the yeast that long before I used it and I didn’t have high hopes that any of it would be viable so I took a sample to check the viability and to my surprise there were some viable cells.

Yeast Starter

Yeast starter on stir plate

I quickly made up a starter opting for 1 litre initially (because the volume I had stored was quite large) to be stepped up to 2 litres if it was successful. The starter was a success with all wort fermented and the cell count looking healthy so I created a 2 litre starter by decanting the beer off the yeast cake and pitching it into a larger flask containing sterile wort the day before scheduled to brew.

What to brew? Something German, something smoked…Smoked Bock!

My recipe was:

7.8kg Weyermann Beech smoked malt

0.3kg Weyermann Carafa Special III

0.1kg Weyermann Caramunich II

1.077 OG

20g Herkules for 40ibu’s

WLP833 Ayinger Brau yeast second generation.

Mash Schedule:

Double decoction

Mash in 500C for 35 mins

Decoct part of the mash and heat to 650C for 15 mins then continue heating to boil for 15mins

Add back to main mash which raises the temperature to 640C and hold for 20mins

Decoct part of the mash and boil for 15mins

Add back to the main mash raising the temperature to 680C and hold for 20 mins

Heat to 750C and hold for 10 mins

Mash complete, runoff in the normal manner and boil for 90mins

Fermentation at 10C raised to 16C for two days at the end of fermentation for a diacetyl rest, transferred and then lagered. I’ve gone with the 1 week per degree of Plato rule of thumb for lagering time so 20 weeks total.

The brewday went well, my yeast starter however was at high Krausen at pitching time so rather than try to separate the beer from the yeast I pitched the entire starter in bringing my starting gravity down to 1072. The strain fermented really well coming down to 1017 over 14 days.

Homebrew Fermentation profile

Fermentation profile for Ayinger’s strain, working well despite being 4 months old!

The beer is tasting excellent and although I should wait till July for lagering to complete I probably won’t!

What’s the longest you’ve ever left your cropped & washed yeast before using it again and how did it perform?

Formerly of Fullers, Thornbridge and Buxton. Now a freelance Black IPA advocate, homebrew geezer and creator of Baby Back Bacon Black IPA™

Be first to comment