Recipe: All-Strata New-World Pilsner

One thing I’ve always liked doing is trying out some new hop varieties. Thanks to a heap of research by the hop breeders, they come up with new and exciting varieties all the time. One of these is Strata, previously known as X331, bred by the Indie Hops company. Here’s what they have to say:

“Strata, formally known as X-331, is Indie Hops’ first hop variety to be released out of our breeding program. Born in 2009, Strata is the progeny of an open pollinated Perle located at an Oregon State University experimental field in Corvallis, Oregon. From the get-go, this hop was out to impress. Between its strong disease resistance, vigorous growing habit, and complex layers of aroma, x331 rose to the top of an impressive group of competitors”

It has been described as passionfruit-meets-pot, I’d say that description is pretty much what you get in the aroma. Think of Galaxy or Mosaic but without that grassy/catty background you sometimes get.

With thanks to Dermott at Beerco, I got my hands on some to sample, and reading through the descriptions they mentioned it also works as a lager hop, so I got to it!

Brewing Process

The recipe was pretty simple:
75% Weyermann Premium Pilsner malt (4kg)
18.9% Gladfield Vienna Malt (1kg)
3.8% Best Chit Malt (200g)
1.9% Weyermann Caramunich II (100g)

I added 0.1 tsp of Sodium Metabisuphite, 2g of Brewtan B to the mash as anti-oxidants along with 4g of Calcium chloride to my filtered strike water. Mash temp was 67C.

Hopping schedule:
3g Strata First Wort Hop
10g Strata 20mins
20g Strata 10mins
20g Strata 5min
30g Strata Hopstand – 20 mins at 80C

I also added 2g of Brewtan B at 20 mins, 1 whirlfloc tab at 10mins and another 0.1tsp Sodium Metabisulphite to the boil.

I fermented with a healthy 1L starter of WLP860 Munich Helles – my current favourite lager yeast.
I added a further 60g of dry hops while fermenting, first addition of 20g was at about 3 days in, 2nd was 5 days in and the 3rd at 6 days.

With a 75 minute boil I ended up with 20 litres at an OG of 1.059 or so, and a calculated IBU of 43.

After fermentation finished, I had an FG of 1.014 or so, making this about the 6% ABV mark, probably on the strong side for a Pilsener but probably about right for an India Pale Lager (IPL), and with a lager like this, it’s debatable as to what it becomes classified as between what you’d call an IPL and New-World Pils.

Results

Just, WOW! Everyone I’ve given this to has loved it. It’s a great malty lager thanks to the Vienna, German Pils malt, and the WLP860, along with a really great passionfruit note from the Strata. It’s not just straight passionfruit either, there’s a complex profile with dank and tropical fruit flavour, you’d swear it had actual passionfruit and pineapple in it.

There’s an amazing lacing all the way down the glass thanks to the copious amounts of hop oil in the Strata plus the chit malt.

At a brew club meeting last week we tried this and then had a beer that was done with 2kg of passionfruit pulp, and the difference between the beers’ passionfruit flavour was surprisingly not that large, going to show that Strata has that flavour in spades.

I’d definitely brew this again. The only adjustment I might make is to back off the Vienna and Caramunich a little as it turned out a really small amount darker than I would have liked, and maybe lower the mash temperature a little to get some more attenuation out of the yeast. The WLP860 yeast tastes great but does leave a lot of residual sugar behind, so if you want it to attenuate more than 75% you need to mash low + long (say 63C for 90 mins) or use a step mash for fermentability.

Yeasts Aint Yeasts

Lately I’ve been reading about how some recent discoveries have shown that some yeasts we thought were hybrids aren’t and some we thought we’re aren’t.

Now I’m just a brewing guy who studied biochemistry a while ago so I am going to probably stuff some of this up compared to people more well-versed in this topic than I am, but here goes…

What I mean by hybrids is that brewing yeasts in the Saccharomyces species fall into two main categories – “Lager” or pastorianus yeast, or “Ale”, cerevisiae yeast. Pastorianus is actually a hybrid of Cerevisiae with another yeast, Eubayanus, that gives it is low temperature and other characteristics that set it apart from the normal Ale type yeasts.

With recent advances in biotechnology including the practicality of PCR and gene sequencing it’s been shown that at least two yeasts and probably more used for a long time as lager / ale brewing yeasts aren’t actually what they seem. WLP800, which is a single strain isolate purportedly from Pilsner Urquell has been shown to be an ale yeast, and WLP051 California V Ale yeast has been shown to be a pastorianus yeast.

There’s still some debate out there about WLP800 which led me to search out for some extra data, as well as working out how else we could get some additional evidence. I jumped onto the NCBI SRA site and searched for WLP800, hoping to at least find some extra data that I could point someone at, and I must have got lucky as there was a huge collection of SRA data uploaded around 31st August to the NCBI site, from a whole number of commercial yeasts.

Turns out it’s for an upcoming study by Hittinger Lab, one of the world’s foremost yeast genomics labs into hybridisation of brewing yeasts, the paper is yet to be released but they have done a huge favour to everyone by releasing this data. From the descriptions of the short reads I could see a hybrid species identification had already been done – showing WLP800 was plain Cerevisiae, WLP029 was Cerevisiae x Eubayanus hybrid, as well as a couple of other interesting categorisations that go against common knowledge. E.g. WY1187 Ringwood being a lager, WLP838 S.German lager being an ale!

Now I don’t really have that much background in these matters so I reached out to a couple of people who I thought might help. One was Suregork, aka Kristoffer Krogerus, yeast researcher at VTT Finland, who’s got a heap of knowledge in the area for sure, even knowing how to make hybrids and study them, and the other was the owner of the data, Quinn Langdon.

That led to two things… Kristoffer agreed with me about how interesting it was, told me a little about how the identification would work and then wrote up this article where he found the WLP351 sequencing matched the sequencing they did on the Muri Kveik.

The owner of the data then got back to me and explained a couple of things… one was that the paper I thought the data was from wasn’t that, and this was for an upcoming paper, and the other thing was that the identifications came from a tool they developed called sppIDer run over the short sequences.

So this tool they released last year known as sppIDer is for analysing genomic content of short read gene sequence data. There’s a paper over here explaining the program: https://www.ncbi.nlm.nih.gov/pubmed/30184140

It takes short read data, and analyses its fit to a reference set of genomic data. You can then set up different genomic data to refence with, and the typical example with this would be S cerevisiae, S uvarum and S eubayanus to determine fit to the different hybrid genomes you’d find in a saccharomyces’ gene sequence. It can then also determine some level of ploidy by interpreting the data to see how much material maps to the different genomes, so this would be useful for identifying Frohberg (ie German) lager strains vs Saaz (ie Bohemian / Danish) lager strains.

I managed to the sppIDer program running. Being Docker makes it easy for me as I work with Docker containers constantly as part of my job at work, the program is based on R, Python and a number of bioinformatics programs such as bwa to process the short read data.

I don’t want to say too much about the results so as not to tarnish the full result release contained in that upcoming paper, but here’s an example of WLP029 short read data being fed into it, the analysis shows there’s plenty of Eubayanus DNA in there.


Once the paper’s released I will do some more analysis, and also Suregork is working on an updated yeast family tree. It’s going to be very interesting seeing where WLP838, 800 and some of these other strains end up in the tree!