Friday, 28 July 2017

Böhmisches Doppelbier

Right. So we’ve already seen Světlý Ležák and Výčepní Pivo. Now we’re onto what is nowadays called Speciální Pivo in the modern Czech Republic.

Braník, my favourite of the Prague breweries, used to brew a cracking 14º Světlé. Which sometime in the later 1980’s was downgraded to 13º. A shame. Of course, nothing like as bad as when they totally shut the brewery. If you wanted to pigeonhole this in an “official” style, I suppose Helles Märzen would do at a pinch. Though Czech Speciální Pivo tends to hoppier than German Märzen.

Let’s crack on with the paraphrasing

Böhmisches Doppelbier is also pale, 14 to 14.5º Balling, highly carbonated beer with good head retention.

It’s brewed from well modified, highly dried pilsener malt. The colour of the beer is pale golden. The malt is prepared in the pilsener way, which is similar to the Dortmund method but is dried at a temperature 5º C higher.

The mashing scheme is a double thick mash where the temperature rises quickly from  50 to 65º C. Mashing in is at 35º C and the temperature rises, either through adding boiling water or fire, depending on whether you prefer to mash in thick or thin, to 50, 65 and 70º C at which last temperature saccharification takes place. Then the first thick mash is boiled for 10 minutes and raises the temperature of the total mash to 56º C when mixed back in. With the second thick mash, which boils for 15 minutes, mash out at 75º is achieved. The whole mash is then left to rest for 35 to 40 minutes and then the wort is run off. In order to create a fine flavour only mellow malt is used which means it lies loose in the tun with only being stirred twice.

The sparge water need to be hot enough so that when the wort is run off it is between 70 and 75º C, so must be not less than 75º C, but not more than 80º C, as this could lead to problems with clarity. Boiling only starts when the first sparge has already been run off. The wort is boiled for 2 hours and the hopping rate is 1.33 pounds of hops per 50 kg of malt. Preferably Saaz hops are used on account of their mild flavour and good aroma. The hop additions are performed like this: the first third are added as the copper is being filled, the other two thirds are blanched with hot water at 80º C and are added to the copper, along with the water, 45 minutes before the end of the boil. When the steam has died down, so 5 minutes before the wort is run off, 8% of the hops are added to the hot wort for the benefit of the aroma.

The yeast is pitched at 5º C and the fermentation temperature shouldn’t rise above 7.5º C. The apparent attenuation (14.5 to 6.5º Balling at time of transfer to lagering vessels) is 55%. The lagering vessels are left unbunged for two weeks then the bunging apparatus is put on. Lagering time is two months.
Source: Olberg, Johannes (1927) Bömisches Doppelbier in Moderne Braumethoden, pp 59-61, A. Hartleben, Wien & Leipzig.

From the description, it sounds as if the malt used for these beers is a bit darker than standard lager malt. Which is interesting.

The mashing description is a bit confusing. The first three temperatures of 50, 65 and 70º C  are just for the first thick mash. Not sure why this only has a double decoction when the weaker versions get a triple decoction.

I’m not totally sure what the hop tea technique of adding hops achieves. I’m sure that there must be some point to it. Is it to isomerise the hops without boiling them? The very late addition of 8% of the hops for aroma does make sense. It also sounds very modern.

55% attenuation is pretty poor, but that’s before lagering. I assume during that process it would rise to over 60%.

4 comments:

J. Karanka said...

Is that the way malt was prepared for this beer or all Pilsner? The text makes it sound the "Pilsner way", which is darker than Dortmund, which was darker than other pale lager malt. Very confusing.

Would be great to have better specs of the malts in a table! :D

Bill said...

I'm curious why metric and avoirdupois measurement systems are mixed. Is this a result of your translation or did the brewery add grain by the kilo and hops by the pound per kilo of grain?

Ron Pattinson said...

Bill,

that's a metric pound: half a kilo. The original text also says Zentner not 50 kg.

Brando V said...

I've observed in my professional career that further attenuation is hard to come by during lagering. And the larger the beer, the less movement occurs. Our Dopplebock doesn't really move at all, and we lager for over two months, sometimes three. Ttis isn't quite to that strength, but if yeast conks out at 55%, I wouldn't hold my breath thinking it would go much further...