Tuesday, 8 September 2015

Beer Style Corner: German Pilsner

Mikko Pludra


German Pilsner is one of the few beer styles available to buy everywhere in Germany, and one of my favourite beers. Although the BJCP style guidelines list no fewer than 19 German beer styles, your typical supermarket or petrol station (yes, that’s where we buy our beer) will only have a selection of Pilsners and some regional specialties (in my home region of south-western Germany, you can always find several Hefeweizens and other wheat beers; in Munich you can of course grab a Helles anywhere; and if you buy anything else but a Kölsch in Cologne, you will certainly be outed as a tourist). Some regional specialties will only be available on draft, like Wiess, Kellerbier or Zwickelbier – the BJCP needs to catch up on those!

Pilsner was brought to Germany in the 1850s from Bohemia, where German brewers had pioneered the style and were very successful with it. It is a straw to light golden, bottom-fermented beer with noble hop aroma and flavour complementing the maltiness from lightly kilned Pilsner malt in perfect balance. The process of long cold storage before packaging is called “lagering” from the German word lagern, meaning storage. This allows the beer to clear, while slowly finishing fermentation and maturation. It is said to produce a rounded flavour and give the beer a longer shelf life. Today, Pilsner is one of the most popular beer styles in the world.

My journey to brew a good Pilsner beer began shortly after I first arrived in Australia, with my first Kit & Kilo brew – a can labelled Black Rock Pilsner Blonde. Not knowing anything about brewing except for the instructions on the can, I dutifully added a kilo of sugar to the water and can contents, gave it a stir, sprinkled the contents of the tiny yeast packet on top, and let her go, for a few weeks.
Suffice to say, the results were not what I expected and I didn’t do much homebrewing for a while! Fast forward about 7 years, and my (much improved) Pilsner wins Best of Show at our Oktoberfest! To say that I was stoked would be a vast understatement. This style of beer is so hard to get right, and to do it justice is a great achievement for me. In this article, I will detail my process and recipe for you – guaranteed no cans of extract or bags of sugar involved!

Recipe

OG 1.049                  FG 1.010                  IBU 30                                    3 SRM                                    5% ABV
To make 23 Litres at 70% efficiency:
92% Weyermann Premium Pilsner Malt (4.7 kg)
5% Weyermann Carahell (0.26 kg)
3% Weyermann Acidulated Malt (0.15 kg)
Mash times: 5 min @ 57°C, 40 min @ 61°C, 30 min @ 71°C, 10 min @ 78°C
Boil time: 80 minutes
29 IBU German Magnum @ 75 minutes
1 tsp yeast nutrient and 1/2 Whirlfloc tablet @ 15 minutes
20g German Hallertauer Mittelfrüh (3% AA) @ 5 minutes
WLP 838 Southern German Lager (420 billion cells)

Process

I use Beersmith 2 for recipe formulation and the Brunwater spreadsheet v1.16 for water calculations.
At least 3 days before brew day, make a starter big enough to create about 420 billion yeast cells. Using a stir plate, I use the following process:
-        Day 1:                  Make a 1.5L starter with 1 fresh yeast vial. Don’t forget yeast nutrient.
-        Day 2:                  Chill starter to settle yeast
-        Day 4:                  Decant spent beer and add 1.5L of fresh chilled wort with nutrient to yeast
-        Day 5:                  Chill until brew day
-        On brew day, decant spent beer off the yeast, and take 1 litre of wort from your boil (can be mid-boil) and chill it down in an ice bath. Add this to your yeast a few hours before pitching to wake up yeast. Make sure this final step is done at or close to fermentation temperature, about 10°C, e.g. by keeping the flask in your fermentation fridge. Now you can pitch your yeast at full kräusen, when the cells are in optimum condition. The yeast and a healthy fermentation make this beer!
Heat your strike water. In lighter coloured lagers, I aim for a water to grist ratio of 3.8 L/kg.
Add salts to your grain (not to your water!) for the following final water profile: Calcium 60 ppm, Magnesium 7 ppm, Sodium 5 ppm, Sulfate 75 ppm, Chloride 65 ppm. In my system using filtered soft Melbourne water, this is achieved with 2.2g of calcium sulfate (gypsum), 1.6g magnesium sulfate, and 3.3g calcium chloride in the mash; and later on 1.7g calcium sulfate, 1.3g magnesium sulfate and 2.6g calcium chloride into the boil kettle.
Dough in for a protein rest temperature of 57°C, and rest for 5 minutes. Ramp up your temperature to 61°C if you have a recirculated mash system. For non-recirculating mash systems, e.g. Esky cooler or similar, add enough boiling hot water to reach 63°C. (This is due to the increased enzyme degradation in recirculated mash systems.)
Check your mash pH and make sure it is at pH 5.4 in a cooled sample or pH 5.2 when measured at mash temperature.
Hold this beta-amylase rest for 40 minutes. Then increase to 71°C and hold there until starch conversion is complete, about 30 minutes. Finish with a mash-out step at 78°C for 10 minutes to halt enzyme activity.

Mash profile for light lagers
Acidify your sparge water to pH 6 if you can, and then slowly sparge at 78°C until kettle full. You can fire up the boiler at 1/3 kettle full to speed up the process.
You will have to adjust the sparge volume to your system and verify your pre-boil gravity according to your calculations. I get about 35.5 litres pre-boil at a gravity of 1.038. Ensure your runoff gravity does not drop below 1.012 to minimise tannin extraction from the grains. Add remaining salts to your boil kettle.
When the boil starts, let the hot break come up and subside, then add your bittering hops. This is your 75 minute mark! I aim for about 30 IBU (bitterness ratio 6.2 IBU/SG) in the finished beer, so calculate your bittering accordingly. This is on the low end of the BJCP range but I find it results in a much smoother and more balanced beer, more akin to German commercial examples.
15 minutes before the end of the boil, add yeast nutrient and Whirlfloc. 5 minutes before the end, add your flavour/aroma hops. At the end of the boil, stir gently to get a good whirlpool going and cover the boil kettle. Let stand for 15-30 minutes to settle hops and break material.
Chill wort and transfer into fermentor. If you can, remove your cold break material before pitching. My equipment (heat exchanger/plastic fermentor) does not allow this to be done easily without transferring to another vessel, but with an immersion chiller it should be as simple as leaving all break material behind. Clear wort makes clear beer!
A note on yeast: My favourite lager yeast is the Carlsberg strain, available as Wyeast 2124 Bohemian Lager or White Labs 830 German Lager. As this yeast was unavailable at the time, I used WLP 838 Southern German Lager. Fermentation and pitching temperatures are 1°C lower when using Wyeast 2124/WLP830 than the numbers given for WLP838.
Oxygenate wort thoroughly. I use a steady flow of pure oxygen for about 60 seconds. If you don’t have pure oxygen available, you must ensure enough available oxygen during the growth phase, by repeating your usual aeration regimen multiple times over the first 6-8 hours after pitching. Make sure you keep everything sanitary when opening the fermentation vessel!
It is normal to see little to no activity when fermenting lagers cold. Your airlock might not even bubble for the first week! This is due to the fact that colder liquids hold more dissolved gases, so the CO2 is not escaping as readily as with ale fermentations. The amount of kräusen on top of the fermenting beer is also much lower than with typical ale fermentations. If you want to make sure you are indeed fermenting, check your gravity with a hydrometer. The strong sulfur smell will also give it away – but don’t worry, this smell will disappear during fermentation.
I like to pitch my lager yeasts 2°C below fermentation temperature and let it rise over 48 hours to fermentation temperature. For WLP838, I pitch at 8°C and ferment at 10°C. Increase your temperature every 12 hours by 0.5°C, so that you are at fermentation temperature of 10°C after 2 days. Hold this temperature for 7-10 days or until you are within 5 points of your desired terminal gravity. Now you can increase the temperature slowly about 1°C per day, until you reach 16°C.
Check for diacetyl: get a small sample from the fermentor into a cup and heat it in the microwave. Smell it. Can you detect popcorn or buttery aromas? If you do, hold this diacetyl rest for 2 days and check again. When no more diacetyl is detected, slowly decrease by 1-2°C per day until you reach as close to 0°C without freezing the beer. I usually stop at 0.5°C, just to be sure I’m not making Eis-Pilsner…
When you are ready to package, take a tablespoon of powdered unflavoured gelatine (from the supermarket’s baking aisle) and add it to 150 ml of cooled, boiled or bottled water. With a sanitised spoon, stir gently and heat it in the microwave to 65°C, stir again to dissolve. You should have a clear, slightly yellowish liquid. Add this to your keg while transferring your beer at lagering temperature and it will speed up the clarification process. Lager your keg under serving pressure for at least 2 weeks, then draw off a glass or two of cloudy liquid. The remaining beer should be bright and clear. Remember to add your finings at below drinking temperature to eliminate chill haze. Flush all transfer lines and kegs with CO2 to keep oxygen away from the beer as much as possible.
To package from keg into bottles, ensure your beer is clear first. Then use a counter-pressure bottle filler or the Blichmann beer gun (which I use) and ensure the beer is as cold as possible while packaging to preserve carbonation.

Possible variations and tweaks

Feel free to use a different lager yeast, Chris White and others say favourable things about WLP940 Mexican Lager. Try a different aroma hop or first wort hopping, said to improve hop flavour from bittering additions. I would like to try one of the modern German hop varieties like Saphir or Mandarina Bavaria. Adjust the mash schedule to suit your system – a single infusion rest at 65°C could be a good compromise. But don’t skimp on the malt! This is the keystone of the beer. Without that typical grainy, graham-cracker-like flavour and aroma of continental Pilsner malt, it’s just another lager beer. But I could image using regular Weyermann Pilsner malt, or Best Malz, or even Dingemans Belgian Pilsner malt. For a northern German variation, substitute Vienna malt for Pilsner malt, increase beta-amylase rest to an hour, increase bittering to 40 IBU and the aroma addition to 25g.
Have fun brewing this challenging beer and enjoy drinking it. Nothing better than a crisp, refreshing Pilsner on a hot summer’s day. Make sure you save a few bottles for the next brewing competition and of course, one for me!

Cheers,
Mikko

No comments:

Post a Comment