The Pilsner Urquell Showdown: Decoction vs. Single Infusion… was it worth it?

Standing over my temperature controlled chest freezer, looking down at my 2 kegs of fully carbonated Bohemian Pilsner, is a very pleasant sight indeed. I used the exact same recipe and maintained the same fermentation schedule for both a single infusion and a decoction version to see what differences could be had. (See original post: Pilsner Urquell: Decoction mash or Single Infusion?) It’s been a long time in the making. Two separate brew days, with the decoction taking me a whopping 11.5 hours (!), 14 days in primary, and another 40 days of lagering. The fact that it is ready to bottle this week, lines up perfectly with us being at the height of summer.

So was it worth it?

The Short Answer:


The Long Answer:

The Water:

To make a true pilsner, there is one thing you cannot skimp on; the water. Plzeň is famous for it’s soft water, and is one of the reasons it was able to brew a pale lager to begin with, when so many others could not. Although Lake Ontario water (Toronto’s water source) is very good, it is still too high in minerals and residual alkalinity. In order to get as close to Plzeň’s water profile as possible, I had to use 20% filtered water (for chloramine removal), and 80% reverse osmosis water. My final concentrations in ppm were:

Ca :7.9   Mg:1.8   Na:9.2   SO4:6.5   Cl:8.4   CO3:14.8

The Fermentation:

Single Infusion



O.G. – 1.050

O.G. – 1.056

O.G. – 1.048

F.G. – 1.019

F.G. – 1.015

F.G. – 1.015

Brewhouse Efficiency: 81%

Brewhouse Efficiency: 91%

It came as no surprise to me that my brewhouse efficiency was higher in the decocted version (91%) than in the single infusion version (81%) It’s one of the reasons decoctions were used in the first place.

One of the most significant differences I noticed in this experiment was in the quality of the fermentation. With the mineral concentration in the brewing water being so low, the yeast in the single infusion really struggled to take hold. The krausen barely formed and I wasn’t sure if it was even going to ferment at all. In the end, it did, but stopped 0.004 gravity points short of it’s estimated final gravity. On the other hand, the decoction took off like a rocket forming a thick blanket of krausen rather quickly. The reason for this is that during the boiling of the mash in the decoction, more minerals and amino acids are released from the grain into the wort, thus giving the yeast more nutrients to absorb.

You may be thinking;

“Couldn’t you just use slightly harder water to supply the yeast with enough nutrients and skip the decoction?”

Yes, you could, but then you’re missing the whole value of what makes a true Bohemian Pilsner so special, the soft water.

“Wouldn’t it still be good?”

Probably, but it wouldn’t be a true Bohemian Pilsner.

The Taste:

The single infusion was lighter in colour, had almost no lasting head, and was thin tasting. The flavours didn’t seem to blend together very well. It was almost as if the ingredients were just mixed together. If it was all you were drinking, it might not be as noticeable, but when compared to the original and the decocted version, it becomes quite apparent. It also tasted slightly sweeter due to the higher final gravity, and had more of an apple, or ‘young’ taste to it.

In the decoction, the final results were definitely greater than just the sum of its parts. It had a much more rich, complex malt character to it. As you can see, the quality of the foam was also much better. The hop aroma in particular really blossomed into something special.

I’m still amazed to think that this recipe is just pilsner malt and Saaz hops.

I will say, I am getting slightly more fruitiness coming from the Saflager S-23 yeast than in the original. It is a German lager strain, and “has been reported to produce some fruity, estery notes” in a beer. I should have used White Labs #WLP800 or Wyeast #2001, which are the Urquell strains. I just thought the dry yeast would be easier to use for this experiment. It would have been a bit much building up 2 starters large enough to provide the appropriate amount of yeast for these 2 brews. Next time I certainly will.

The Carbonation:

Traditionally, as a means to carbonate their beer, lager brewers would capture the natural CO2 being produced during fermentation and allow it to dissolve back into the beer. It is also the more environmentally friendly way to do it, and is also very cost effective because it eliminates the need for expensive forced carbonation equipment as well as the  CO2 itself. There is an ongoing debate among brewers whether the CO2 produced during fermentation, or the CO2 you force into your beer is better. CO2 is CO2 right? Well, yes, but each does seem to provide a different quality of bubble. Natural carbonation, be it from bottle conditioning, or from fermentation, seems to have a softer feel to it. Don’t ask me why, I have no idea of the reasons. Personally, I force carbonate my beers. I find it easier, faster, and generally gives me greater control over the volume of CO2 in my beer. Plus it allows me to keep my beer clearer than when I bottle condition it.

On the negative side, I have found when my beer is over forced carbonated, it becomes ‘sharp’ on the tongue (think soda pop sharpness). To compensate for this, I usually carbonate slightly under the point at which this develops, regardless of style.

I was able to capture some CO2 during lagering, but did have to top it up when it came time to bottle. Because of this, I can notice a slight difference between my pilsners and the original. The original is very soft and smooth, whereas mine has the slightest bit of sharpness to it, but it is very minimal. Next time, I will try to capture more natural CO2 during fermentation.

My Conclusion:

For me, this experiment answers the whole decoction vs. no decoction debate. It definitely makes a difference in the final beer, and for the better. I wish doing a decoction mash didn’t take so long, but from now on, this is the only way I will ever brew a Bohemian Pilsner.

You may be thinking, “Does it really need to be a true Bohemian Pilsner?” Of course not. Your beer can be whatever you want it to be. I personally like the unique quality of Pilsner Urquell, and hold a deep respect for it’s history and it’s artistry. So if I’m aiming to replicate it as best I can, then this is the way to do it.

Try it for yourself!

See the final recipes here:

Hoptomology’s Pilsner Urquell Clone – Single Infusion

Hoptomology’s Pilsner Urquell Clone – Enhanced Double Decoction

Previous posts:

Pilsner Urquell – Decoction mash or single infusion?

The Pilsner Urquell Showdown: Decoction Day…



8 Responses to The Pilsner Urquell Showdown: Decoction vs. Single Infusion… was it worth it?

  1. Interesting experiment. Good for you for having the patience to pull it off!

    I wonder if you had done two single-infusions, using more malt for a higher OG for one of them, and were able to get a lower FG for that beer… I assume you would notice a difference b/w beers there as well. Mind you, you DID say the higher-FG beer (single infusion) was thinner than the decoction, and lower-FG, beer. Interesting.

    When you say 20% filtered water, do you mean a carbon-filter? I was under the impression that filtering water didn’t remove chloramine. You’ve said you use metabisulfate… did you do that here as well?

    • Cheers, it was a long one, but a good learning experiment.
      Good point on the filter, you’re right, a carbon filter wouldn’t remove the chloramines. I must have had that written from before I actually did it. I used a tiny bit of meta bisulphite like I mentioned to you before. (I’ll correct it in the post)

      Yeah, it was strange, maybe if you compared 2 single infusions, one with a lower and one with a higher gravity, you might notice the difference, because higher FG usually equates to a fuller body, but when compared to the decoction version, any difference just pales in comparison. Not like the decoction is heavy or thick, just way more ‘rich’ tasting if that makes sense. Something seems to happen that brings everything together more. maybe the extra nutrients brought out in the boiling of the grains? not sure…

      Next time it will be a little shorter of a brew day, plus I’m getting some of the Urquell strain from White Labs this week, so I’m looking forward to brewing it again…
      Cheers Shawn!

  2. Did you brew this for the Pilsener Urquell contest? If so hpw did you do?

    • I actually found out about the contest after it was lagering ,but unfortunately it was only open to residents of the US, of which I’m not, so I couldn’t enter it.
      I wish I could have though!!
      Not that I would have expected to win it, but what a great prize to actually get to go to Plzen!

  3. I drank Urquell all weekend camping in honour of your blog post. Nicely done! Not sure I could do it.

    • nice! and thanks!
      Was a long process, but a great learning experience and with decent results.
      It’s honestly a lot more complicated on paper than it is in practice. Once you map it out and actually get to doing it, it’s pretty straight forward, just longer.
      If you ever wanted to try it, I’m sure you could do it.
      btw, looks like you’ve got some great homebrews on the go as well! nice job!

    • btw, thanks for the link to my site! I appreciate it, just added yours to mine….

  4. Awesome! Thanks!

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