Quick Sours with Kveik and L.plantarum

For a long time in brewing, the way to brew sour beers such as Berliner Weisse, Gose, Flanders Red and other beer styles was to brew with mixed cultures, which took its time to create the right level of sourness or flavour. Enter the modern Kettle Sour which aimed to do away with that, by having selected lactobacillus strains that could produce lactic acid in an anaerobic environment at the right temperature in a short amount of time.

Normally, the temperature for kettle souring strains such Lactobacillus Plantarum is between 30-40C or even higher. Which normally would be outside the desirable temperature range of Saccharomyces strains.

Thanks to the efforts of people like Lars Marius Garshol and the farmhouse brewers of Norway in keeping cultures alive, Kveik and other farmhouse yeasts like the Lithuanian Simonaitis can readily survive conditions between 30-40C and still produce good beer.

Putting this together is not my idea entirely, but it was something i stumbled upon after going looking for anything i could find about whether people had done this before. There was some information on Milk the Funk and the HomeBrewTalk forums about this which gave me more of the detail.

To break the method down simply: Pitch hot with kveik with L.plantarum with no hops, and then add hops when the target sourness is reached.

According to the spec sheets published by Lallemand about their Wild Pitch L.plantarum strain, souring is inhibited by as little as 4-5ppm of Beta Acid and Alpha Acid. That’s as little as 2-3g of hops in a 20L batch to reach 5ppm based on the hops being 5% beta acid, pretty standard for most hops.

To put this into practice, you can basically make unhopped wort, pH adjust after boil with acid to less than pH 4.5, chill to less than 40C, add L.plantarum (10g per hL or 2g for a standard 20L batch) and Kveik/Farmhouse yeast e.g. Voss, Simonaitis, Lutra, Hornindal, etc. The pH adjustment is to minimise the effect of the protease enzymes from the Lactobacillus on head retention like you would with a kettle sour. Monitor pH over the fermentation at least every 4 hours, as the souring process will happen very quickly. Normally between 12-16 hours I reach pH 3.7 which is where I like some of my sours to finish up, but go for longer if you want something very sour such as ph 3.2. Once that target is hit, dry hop or add hop tea with at least 5g or more of hops. pH may go down or up slightly after dry hopping as the pH stabilises. As it’s unhopped and may taste a little odd after fermentation completes you can add bitterness by boiling hops in water/wort, or add iso-hop extract to add some bitterness.

Another tip to improve head retention is a protein/foam rich grain in the grist such as Chit, Wheat Malt, Unmalted Wheat, Carapils or Oats.

Note that Lactobacillus Brevis or other lacto strains can be hop tolerant so I wouldn’t recommend this method with those strains. Stick to kettle souring with a boil after souring for those.

Below is a recipe for making 20L of Gose with this method. This is a sour with coriander seed and salt added. Leave the coriander and salt out if you want something more like a Berliner Weisse or a cleaner canvas for adding fruit to make a fruited sour.

Recipe

“The Quick and the Dead”
Style: Gose
OG 1.044 / ABV 4.5% / 0 IBU / 20 Litres
Grainbill:

  • 62.5% Pilsner or Pale malt (2.5kg)
  • 20% Wheat Malt or Unmalted/Flaked/Torrified Wheat (0.8kg)
  • 15% Vienna Malt (0.5kg)
  • 5% Chit Malt (substitute Carapils if you can’t find that) (0.2kg)

5grams Calcium Chloride added to mash
Single Infusion 67C for 60 mins
10g Salt added to boil
10g Crushed Coriander seed added to boil
60 min boil unless using Pilsner base malt – use 75 min boil.

There is no need to add whirlfloc unless you really want it – this style can be hazy
Add Phosphoric or Lactic acid to kettle post-boil to adjust pH to under 4.5

After boil. chill to under 35C
Pitch 2g Lallemand Wild Pitch plus Kveik such as Lalbrew Voss

Use a heat belt to keep temp above 30-32C

Once target sourness hit, dry hop with 30g Citra, Mosaic, Cascade, Amarillo or other citrusy-style US hop

Make up a hop tea by steeping 10g of hop pellets in boiling water for 10 mins, strain the result and add to the fermenter just before fermentation completes to add a little bitterness to balance the sweetness. Do not overdo the bitterness – bitter and sour don’t work that well together!

I’ve shared the recipe on Beersmith Recipes: https://beersmithrecipes.com/viewrecipe/3292087

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!

Kölsch yeast experiment

So one of my favourite beer styles is Kölsch. While I’ve never been to Cologne where the style originates, I’ve had a couple of them and brewed them to the best of my ability, doing reasonably well in competitions with them. The trick is to mash for dryness, either a step mash or a 62-63C single infusion, with a long mash of 75-90 mins, and get the yeast right.

This is where this experiment comes in. I’m trying to find the best yeast choice for both my homebrewed efforts and for when I eventually make the leap to going commercial, and there’s a multitude of options out there now.

The yeasts of choice for this experiment are the new Lalbrew Köln dry yeast, Gigayeast’s GY021 and White Labs WLP029. Before I’d started this I have also used Wyeast 2565, rumoured to be the Weihenstephan 177 strain, and the White Labs European Ale strain, as well as WLP036 Alt. 2565 and European Ale are good flavour wise but take forever to clear to brightness, and WLP036 isn’t a kölsch yeast, it makes alright beer but I left it out.

Yeasts… The WLP029 was probably 15mL of thick slurry. Gigayeast was split up into 4x vials so approximately 50+ billion cells pitched.

Recipe was simple – 94% Pils , 4.5% Wheat, 1.5% Acidulated. Mash and sparge water adjusted with Phosphoric acid to hit a theoretical 5.2pH in Bru’n water along with about 4g of CaCl2 and 1g CaSO4 in the 15L batch. OG 1044, and around 27 IBU’s with Perle for bittering and Perle + Huell Melon for flameout. Looking back over my notes the Pils was actually a 60/40 split of 60% Barrett Burston Pale and 40% Weyermann Bohemian Pilsner.

Mash temperature

3x 5L demijohns were used for the fermentation, splitting the cooled wort into these, aerating each for around 1-2 mins with an airstone + bubbler then pitching. WLP029 was fresh slurry from a starter, GY021 was split from a fresh pack, and Koln was approx 5g rehydrated from a pack.

The demijohns.

Fermentation temperature was around 17C for all 3, and fermentation continued for 2 weeks – around 4-6 days active ferment and then conditioning / maturation at the same temperature – no cold crashing. Each demijohn got a small amount of Gelatin, and 2mL of White Labs Clarity Ferm was added during maturation to each, for no real reason other than testing that out.

Lag Time

WLP029 fired up first. GY021 was second and Koln took longer than both to get started and show signs of fermentation.

The WLP029 on the left is fermenting, but nothing’s happening over in the Koln!

Krausen

WLP029 had a decent krausen, GY021’s krausen was highest and Koln did eventually get a decent krausen, probably in the middle.

Sulfur & Diacetyl during fermentation

With only a small amount of wort no real sulfur was noticed near my fermentation, but pulling a couple of samples with a pipette did show a little more in the GY021 compared to the others. None of it stuck around though by the time it came to bottling.

I didn’t have enough of a sample to detect much diacetyl or run a forced diacetyl test during ferment but nothing seemed to be overly buttery after active ferment.

Attenuation & pH

The Koln took a fair amount longer in active fermentation than the other two. WLP029 was mostly over in 3-4 days, GY021 a little longer and then Koln probably bubbled away for 6 days. All of them seemed to still generate CO2 for a couple of days afterwards very slowly.

The final beers ended up a little different in attenuation, Koln 1.007, WLP029 1.008 and GY021 1.006. pH was around 4.1 for the Gigayeast, 4.2 for both the WLP029 and Koln.

Final Results & Conclusion

All 3 produced great, crisp and bright beer that’s the hallmark of a kolsch.

I’d have no hesitation in using any of these yeasts again, especially the Gigayeast 021 which may have now become my new favourite kolsch yeast, but the dry version is also good to my palate.

EDIT: I’ve tasted all the beers further now they’re carbonated and the WLP029 is no slouch, it’s crisp and clean. GY021 has a little more roundness of flavour, but there’s maybe a little harshness in the finish, and the dry yeast has a little bit of extra fruitiness/esters on the palate maybe a little like an English or American ale yeast, it’s not an overpowering flavour but noticeable. With such a subtle style any flavour sticks out, so all of these still made good beer, but really it’s a matter of preference as to how much flavour you want or prefer.

Over the next little while I’ll try out the beer with some other people and see what they think, while I don’t have enough beer to go full Brulosophy style with 20 tasters, it’ll be interesting to see what happens. And i’ve also entered the Gigayeast and Dry versions into a local homebrewing competition, so we’ll see what happens there (Edit: see the final section below for how it went)

I’ll take a couple of pictures when I can to show you how bright it is…

A note on price though… here in Australia at least there’s little difference in price between a vial of White Labs or Gigayeast and the 2 packets of the dry Koln yeast required to obtain the correct pitch rate recommended by Lallemand. I can see that a few microbreweries may like to use the bricks of this yeast to make Kolsch, clean ales or pseudo-lagers.

Other Thoughts

After I started this experiment, I also found some new gene sequence evidence that WLP029 may actually be a lager yeast… stay tuned for that one. It’s the same data from the Hittinger lab that Suregork was able to identify the Muri Kveik as being identical to WLP351 – http://beer.suregork.com/?p=4094 . I guess that explains some of the clean-ness and its use for “pseudo lagers” or quickly brewed lager-tasting beer in a lot of breweries…

Also in the same set of sequencing it turns out that WLP800 most probably is and WLP838 may be actually ale/cerevisiae type yeasts – these could also be interesting targets for an upcoming experiment.

Followup

I did pretty well with the GY021 and Lalbrew Koln versions at the recent NSW State homebrewing competition. The Koln-fermented version scored 84 points and the GY021 scored 78 points ( a couple of points lost from sulfur as it was only 2 weeks in bottle before tasting), however at the mini-BOS round in the category the GY021 ended up taking 1st place in the Pale Ale category and the Koln, 2nd place in the category. I guess maybe the sulfur disappeared a little between the scoring round and the placing round.