In July of last year, we noticed that something had gone wrong with the house culture of yeast and bacteria that we used to ferment our beers. I wrote about the issue at the time (here) without knowing what had caused the it.
What did become clear straight away, however, was that we had hit a fork in the road. It was no longer possible for us to use the culture of brewers yeast, wild yeast and bacteria that we had foraged for, built up and worked with for the past 5 years. In the work of tracing back where things started to 'go wrong' in the ferments, it was evident that we would continue coming up with the same problem, and problematic fermentations = dumped beer, if we simply continued to use the same house culture.
So in the first part of this post I'm going to write about our new culture and our decision to restart our brewing with a culture of yeast and bacteria that derives wholly from native flowers, a rededication to the microflora of NSW done wholeheartedly with the benefit of 5 years of experience behind us.
In the second part of this post, I'll address, to the best of our knowledge, what happened to our culture and how we tracked that down. I'd like to put up front that this tracing and identification work was mainly the work of Chase Saraiva and I'll acknowledge and thank him for this work straight away.
A new community
But as promised, I'll put where we are first, then talk about where we were.
The biggest problem we had to immediately overcome as a brewery was not addressing what happened to our culture, it was instead not being able to successfully ferment any beer. Sure, they are tied to one another, but for a brewery such as ours (well any brewery really), not having anything in tank is a really bad look. The complication to our predicament, however, was that we did not have the option to simply ring the yeast lab for a fresh pitch to start over.
In the past, I had spoken of this moment, spoken of how we would be able to re-build the culture from our barrel stock and continue. Which, if you read back through my blog post from back then, I did do... however, to jump to a later stage, this 'rescue' culture developed the same acetic, hyper sulphur off-flavours that had been the initial problem after a handful of generations.
But, something else was roaming in the water as well, a desire to address something that had been a source of confusion for some, even consternation for others, the pitch of brewer's yeast that was added to our first ferment and continued to live in our original house culture for the first 5 years (2016-2021) of brewing at Wildflower.
Since we have opened Wildflower, we have learned many things. (<- huge understatement) Most pertinent to this conversation is the leanings we have learned from straight native ferments from flowers, which I'll just loosely define as ferments which are derived wholly from foraged blossoms without introduction of any yeast or bacteria grown in a laboratory environment. Lesson #1 in this volume is that these ferments can be surprisingly clean... and lovely. Lesson #2 is that to successfully work with them, one does not need to ring in the aid of a clean saccharomyces strain, they have that all by themselves. When we started, however, I will be honest and admit that while I may have known lesson #2, I did not wholly trust it. Having a pure-culture strain of saison yeast in amongst the culture provided a solid backbone for the wholly foraged, captured, borrowed 'bugs' (Brett, lacto, pedio, wild yeast, others) to build upon. But, I thank beers such as Waratah and Wattle drops which have encouraged me to change my thinking on something through my lived experience, a wonderful part of keeping an open approach. These two beers year after year remained unique, yet wonderful while utilising wholly flower-derived microflora for fermentation from start to finish.
I might take this moment to make a case that although this is the path we have decided to walk on next, making beer without the introduction of lab-propagated yeasts or bacterias, by no means does this place our beer in some different realm, an upper hierarchy of fermentations. There does seem to be out there in the market, amongst the consumer rhetoric, an idea that the closer to 'natural' or wild the better. I can happily admit that I would much rather consume a well farmed, certified organic wine that uses an inoculated yeast, than a conventionally farmed product which is made rarefied by being fermented with airborne or otherwise yeasts. I think this is another point where my personal approach may have shifted over the years, my concern lies far less with the methods of fermentation, rather far more with the methods of agriculture. Inoculating or not-inoculating your ferment has exactly zero impact on anything other than the flavour profile and market perception of your product. Through both methods you produce CO2, alcohol and a symphony of byproducts and compounds which make fermented foods and drinks so fantastic. The farming of the raw materials, on the other hand, has a far more profound impact... on carbon sequestration, the health of an ecosystem, the health of your ferment alone, and the list goes on.
Personally, I adore the nuanced, idiosyncratic flavours of products that are fermented with microflora that is introduced in other ways than lab-propogaged inoculations. Of course I do, it's literally my job. However, in no way do I place these products on a pedestal, exuding superiority over makers of products who do not practice similar methods. I also adore well made lager, soft cask ales and bright IPAs. I deeply respect the persons who are able to craft these beers and do not assume that ours possess a differing level of sophistication than these. In fact, our method of fermentation in some ways is far more forgiving than an exacting practice such as crisp lager. One could certainly argue that our process is far easier actually. Allowing for and baking in, a margin for error that we can call acceptable.
At any rate, though, this new house culture that we started to use confidently in December of 2021 was built just the same as the culture we started with back in 2016. This 2021 culture was built from ferments originating from three blossoms, a wattle from Murrumbateman courtesy of Bryan Martin combined with a white blossoming melaleuca shrub and wattle blossom again both gifts from Dan McCullough in the Southern Highlands of NSW.
Upon receiving each of these three blossoms, amongst others, they were covered in wort and left to commence fermentation on their own. Once fermentation had begun, we typically step-up the volume of the ferment by adding more wort to encourage additional growth of the saccharomyces strains driving the initial fermentations in their exponential growth phase. We may do this even one more time while these fermentations remain in contact with their inoculants, their flowers. Usually at this stage, these ferments sat around 250-300 litres which is enough to fill a barrel, so if they are tasting nice, as these three did, we would fill an oak barrel with this fermented beer of around 4 weeks old, collect the yeast slurry and pitch that into another new fermentation in a seperate vessel which no longer contains the original flowers.
This is a slow, iterative process. We started building this new culture almost as soon as we started having problems with the old one in July 2021. However we waited until December to be confident, really, with the beer these seperate yeast cultures made. We wanted to see them age out and develop a little bit before jumping in and brewing ~3000 litre batches. The process I describe above took these four months, during which we made little to no beer, as we didn't have yeast to do it.
It was tough to keep motivated at times and the joy of this work was at probably an all time low for me. It was quite difficult to stay positive when you had little to no idea if the time and grown materials you had just put into making wort were going to be rewarded with a successful fermentation, or if they like so many others were destined for dumping. Further diminishing the enjoyment of the job was the fact that the initial problem we found in the old culture kept bugging us and leeching its way into even these attempts to restart the culture. I can't pinpoint exactly when, but at some stage on this journey we came to realise, and acknowledge that the undesirable flavours and aromas which we had identified as problematic in our old house culture, were in fact not in the culture, not a part of it, instead something exterior that was being introduced to it. It turns out it was via the wort we were using to feed it, I'll explain.
The cause of concern
Ideologically, I find it very hard to use the word infection when it comes to what happened to our culture. In many ways the yeast and bacteria that we employ to make our beers in the first place represent an infection. The connotation with the word is certainly negative, yet we know that 'infecting' wort with wild yeasts, bacterias and other organisms can in fact produce something wonderful... which is not negative. Furthermore I have difficulty agreeing that there is anything such as a failed, or bad fermentation. The organisms that produce flavours humans may not agree with are not doing anything wrong... you're alright I guess acetobacter... they are doing just exactly what they need and want to do, reproduce and keep living. Thus just because their fermentative byproducts are not agreeable to the human palate does not mean they are bad, it just means as practitioners of fermentation, maybe we shouldn't sell that to a customer.
So that being said, what we did have on our hands was an external and unwelcome introduction of pectinatus into our fermentations. I'll leave it to you to read about this organism but to note are that it thrives in anaerobic, moderate-low pH and alcohol ranges, pretty much our beer was an ideal breeding ground.
Chase was the one who identified it, off taste and research. Once we had a name, and a target as to what the problem with our fermentations had been, we were able to start addressing it. The organism reproduces extremely quickly and it has been said that even a single cell can grow to alter the flavour profile of a large batch of beer in a matter of hours. We figured it must have been living somewhere we hadn't considered, somewhere between the start of the heat exchange and the addition of yeast.
So we hit all those pressure points hard. We developed tests and process flow changes to see where it developed, or not. The primary fermentation vessels and SS IBC transfer totes were cleaned over and over, we replaced all our hosing at the brewery along with seals and pump impellers, we analysed oxygenation levels in our wort and our yeast collection/pitching practices. This was constant work and while we had wins along the way there were also setbacks.
One major win, though, was when we found what I believe was the source of the organism in the brewery, of course a completely obvious thing that we had just overlooked, a ball valve at the bottom of one of the totes we used for wort transfer. When we were really hitting our heads against the wall, we decided to fully take them apart and boil them in pieces. It was in taking them apart that we of course realised/remembered that when a ball valve is partially-open or partially-closed, there is a very small cavity inside the valve which is exposed, and then hidden away again when the valve is fully open or fully closed. It was in taking this apart that we saw the bio-film and realised our mistake.
This is kind or hard to admit and talk about but I share it so that others might not do the same. As brewers, particularly in making clean beers, cleanliness and sound process flow is extremely valued. It is crucial to the job and we should have seen this earlier, we should have addressed it. When cleaning the vessel, the valve should be allowed to sit halfway between open and closed to allow for the cleaning of this little cavity, you know we do that now!
The other thing we did to completely eliminate the even slightest chance of this organism continuing to take unwelcome occupancy in our transfer totes was to heat them up, fully, to an extreme temperature. So for two batches of beer in mid-December we bypassed the heat exchange at Batch (where we make wort) and filled the IBCs each with near-boiling wort and left it there for about 30 minutes before casting that wort into our coolship for an overnight cool and inoculation. It actually worked really well and those batches were combined in foudre and are showing promise, even for young coolship beers made on a 14deg overnight low summer evening.
Another side bar that I really do love that one of the solutions here was to go a ways back and consider the benefits of a technique used before the modern era of brewing with knowledge and detection of microbes.
But in order to know that we were really hitting the right nail, or addressing the right microbe we do owe a huge deal of thanks to both our neighbour Rene at Young Henry's Brewery in Newton and Graeme at Tooheys in Lidcome. Rene ran close to 30 samples for us through PCR testing over multiple months in order to help us detect and investigate the microbe itself and its source. This simply would not have been possible without Rene's help. Thank you.
Also, a massive, massive word of thanks to the Graeme Gibson, Head Brewer at Tooheys in Lidcome for not only your words of empathy and friendship at a pretty crappy time to be a brewer, but also for the enriched PCR we received to confirm that there was no pectinatus present in our ferments (new culture, post heavy cleans and new SOP). Hooray! Honestly it was the Christmas present I wanted the most.
Following those results we brewed 12 times in 4 weeks, thats a lot for us... we are nearly caught up to where we should have been. Although that was the reason for the pause in availability of our Organic Table Beer. But even that will return next month and I hope to never run dry on it ever again!
In the aftermath of this, we have had a good deal to think about why the organism had taken hold... there is obviously the ball valve, but also pectinatus loathes oxygen so why had oxygenated wort not killed it almost instantly during transfers. Well, we recalled that for some time earlier this year we lowered the oxygenation level of our wort at knockout and sometimes not at all. The reason to do so was to address the level of enterobacter we were seeing in some of our ferments. These organisms also hate oxygen and while quite important for the initial stages of lambic beers, create some pretty strong cooked vegetable/baked beans aromas that take huge levels of brett (something our culture is not heavy in) to clear up. So it is also interesting to me that in trying to minimise the impacts of one organism we may have upset some intricate balance that we operate within. It's not a rule or anything, just a thought for pondering.
A New Beginning
To finish this rather long story I suppose I will finish back where we started, and that's where we are at as of now. So since December last year, well even a little before, we have been making beer exclusively with a house culture of yeast derived wholly from flowers foraged here in NSW. It will take some time, likely a couple of years for this primary fermentation yeast to be the bedrock for all our ferments and until that time, we will not change our labels. Currently there is a note that our beer contains 'brewer's yeast' which was that initial lab-propagated saison strain we pitched into our first ever ferment in December 2016.
You will notice, however within the year changes to our ingredient list as now all our beer in barrel is made exclusively with certified organic grains and we will make note of this on Gold, Amber and Good as Gold labels as we have with the 2021 'St' fruit beers. I'm extremely proud that every kilogram of grain we have used in the past two years has come from predominantly Sam and Chris Greenwood's farm or otherwise from the Woodstock farm 'around the corner'. Both certified organic and farming grain in such clever, soil first methods. I am very much looking forward to acknowledging their work on our labels.
Dec 2016-Dec 2021, five years with the old culture. A good innings for sure. There are things already that I have missed about what it could do... we do feel like we were just starting to know it... but I'm happier and more excited about the shift it allowed us to take and where we are now. This new culture is bright and spicy while still maintaining a lovely softness and full-body mouthfeel with age... it is kicking goals with our saison-inspired beers and that is a major win for sure.
If you have made it this far, thank you for your interest in what happens here at Wildflower. I really do appreciate how forgiving so many of you are of us while we still learn our trade. It makes this job quite exciting and enjoyable at the same time. If you are a fellow fermenter, hopefully you may find this helpful... either as a roadmap of what not to do or an empathetic embrace that even when its your full time job, things happen.
-topher
