First Brew of 2018 - Double-decocted Oktoberfest

[strange-steve]

Well after possibly the busiest two months of my life, I finally managed to squeeze in a brew today, an Oktoberfest lager.

I want a deep, rich, complex malt flavour in this so I followed some of the advice from "Brewing better beer". I used a sort of hochkurz mash schedule with two decoctions and I skipped the sparge (which apparently improves malt flavours). Took a bit of an efficiency hit, but I expected that and increased the grain bill a little to compensate.

Oktoberfest

Batch Size - 19 L
Original Gravity - 1.056
Final Gravity - 1.014
ABV - 5.5 %
Colour - 12 srm
Bitterness - 27 ibu
Boil Time - 75 mins

Grain Bill
2.2 kg Pilsner malt (38%)
1.3 kg Vienna malt (23%)
1.0 kg Munich I (17%)
0.75 kg Munich II (13%)
0.4 kg Caramunich II (7%)
0.08 kg Acid malt (2%)

Hop Bill
10 g Magnum for 60 mins
25 g Hallertau Mittlefrueh for 20 mins

Mash Schedule
20 min rest at 62°
Extract 5L decoction and boil for 15 mins
45 min rest at 68°
Extract 7L decoction and boil for 15 mins
10 min rest at 77°

Notes
Ferment at 10° with Wyeast 2633 Oktoberfest lager blend
2 day diacetyl rest at 19°
Lager for 4 weeks at 0°

 

[serum]

Nothing like a decoction to keep you even busier! Hope this one goes well

 

[BeerisGOD]

What does acid malt bring to the table?
Ive only noticed a couple of beers that use it. Adnams broadside for one

 

[IainM]

What does acid malt bring to the table?
Ive only noticed a couple of beers that use it. Adnams broadside for one

My understanding is that it lowers the ph without you needing to add acid, which would contravene the Reinheitsgebot.

 

[serum]

What does acid malt bring to the table?
Ive only noticed a couple of beers that use it. Adnams broadside for one

I saw that in the Graham Wheeler book. It's an odd one because it's effectively water treatment. You might need it, you might not depending on your water.

 

[strange-steve]

Nothing like a decoction to keep you even busier! Hope this one goes well

Yeah it was a long brewday alright, but good to get back on the horse

 

[BeerCat]

Nice one Steve. I have wanted to do a decotion mash for a while but i realised my pan is so thin it would probably scorch so i am putting it off for now.

 

[Simonh82]

Quick question. If your first mash rest is at 62°C for 20 minutes, do you wait until the end of that rest before removing the first decoction and heating it to a boil and boiling for 15 minutes? So in effect, the remainder of the mash might be at 62°C for say 40 minutes in total before the temperature is raised with the readdition of the decoction?

 

[strange-steve]

What does acid malt bring to the table?
Ive only noticed a couple of beers that use it. Adnams broadside for one

As above, it's for water treatment, a substitute for adding lactic acid directly. It can add a bit of tang, but only when used over 5% or so.

 

[strange-steve]

Nice one Steve. I have wanted to do a decotion mash for a while but i realised my pan is so thin it would probably scorch so i am putting it off for now.

Actually the SS pot I use has an incredibly thin base too, I just heat it gradually and stir constantly to avoid scorching.

 

[strange-steve]

Quick question. If your first mash rest is at 62°C for 20 minutes, do you wait until the end of that rest before removing the first decoction and heating it to a boil and boiling for 15 minutes? So in effect, the remainder of the mash might be at 62°C for say 40 minutes in total before the temperature is raised with the readdition of the decoction?

Yep exactly that. The entire mash was probably about 2 hrs 15 in total.

 

[strange-steve]

Well about a week in and gravity is down to 1.022 and I've started a slow ramp up to 19°. Very sulphury aroma (not unexpected with a lager) but otherwise tasting pretty good so far.

 

[strange-steve]

Finally got this bottled after 5 weeks lagering at 0°. The flavours seem pretty good at this point, although I thought I detected a little acetaldehyde which is odd. We'll see what a couple of weeks carbonating does.

 

[Clint]

Sounds interesting...ah acid malt. ..now I know why I bought it!

 

[Martybhoy]

Hi Steve, how thick did you make the decoction? I've read that they should be quite thick, but that worries me with regards to scorching .

 

[strange-steve]

Sounds interesting...ah acid malt. ..now I know why I bought it!

Yeah it's a bit easier to measure out than lactic acid, plus it feels a little more "authentic" for this style of beer.

Hi Steve, how thick did you make the decoction? I've read that they should be quite thick, but that worries me with regards to scorching .

The first was thick, mostly grain with just a little liquid but you do have to keep stirring throughout to avoid scorching. A gentle heat helps also, the temperature increase should be relatively slow. The second decoction was thin, mostly liquid, which helps lock in the profile by acting sort of like a pre-mashout.