Recent study found that very turbid wort carrying 50 times the normal amounts of solids both into the boil and into the fermenter, thus increasing the amount of both zinc and lipids, led to more rapid fermentation, healthier yeast, no need for zinc supplementation, and no need for aeration, as the lipids provided meant yeast could skip the aerobic phase and just take up sterols rather than synthesize them. Also surprisingly led to reduced esters and fusels. And note: this was done by – gasp – Germans! Recent MBAA podcast, and abstract here Technical Quarterly
Does not surprise me either, but now I have to re-think my clear wort transfers with yeast supplement added to the late boil. Everything old is new again!
Sounds interesting, although a single study is just that, a single study. I’d read the paper if it were free. Did the study also examine the effect on final clarity and shelf life?
I don’t know if it’s a contradiction so much as a balancing between competing goals.
For example, we know cloudy wort has a significantly higher concentration of unsaturated fatty acids. UFAs contribute to yeast viability and can inhibit potentially undesirable esters. On the other hand, they are detrimental to foam stability and can accelerate staling.
I too would read it if free. :) The researcher interviewed in the podcast indicated no downside. “I see no benefit from clear wort” or such words. I just assume that Germans would be sensitive to such issues. Maybe someone who has access to the paper will clarify (pun intended) this. FWIW in my experience, (slightly) cloudy wort seems (anecdotally) to give clearer, more stable beer. Experiments by Stone last year also initially yielded such a result, but they gave up because they were fouling their heat exchanger.
(I think on most homebrew systems it would be difficult to achieve the level of turbidity this new German system allows. But the old homebrew wisdom still holds true, a little trub is just yeast food.)
1 german is not all Germans. Selling brewing systems means nothing. Look how many subpar brewing systems we sell.
It’s been studied as nauseam that cloudy wort contains more “stuff”. Of course it does that’s literally why it’s cloudy. I am not going to debate which is better. There are tons of abstracts and full papers on it.
One tip though. When you are trying to follow professional german brewing tactics my first stop wouldn’t be MBAA (America’s) it should be the country of origin and in this case brewingscience.de. Conversely if I was looking to brew NEIPA I would not look at brewingscience.de. If it’s German and backed by BS, it’s legit. If it’s not… it’s fake news. Gotta understand the sources and the context, that’s all.
True, what’s good for German styles may not align with other styles. But beyond that, even within a style or tradition, I think the balancing of goals narcout brings up must be considered, and the type of brewery and market then comes into play. These new brewhouses, I gather, appeal to small craft and pub type brewers in Germany, who like elsewhere, want quick equipment turnaround because they are making smaller amounts of a large number of products, quickly sold on premises or locally. Most of the literature has addressed the needs of large scale producers with retail and export sales in mind, where long term stability becomes paramount. (And yet they still use green bottles… ??? ) Maybe on the homebrew level the question is, do you want today’s brew to survive in bottle until next year’s NHC, or are you trying to have a keg that will be entirely consumed at an event in two weeks? Or in between? It is a balancing act. But I think the risks and benefits all around can be overstated (especially for homebrewers) unless you are pushing your system to extremes. IMHO.
I have always wondered if it is better to allow the yeast to synthesize sterols rather than absorbing them up and skipping the aerobic phase. It seems to me that the yeast might be more robust if they went through the process of synthesizing sterols for stronger cell walls and better budding. But that is just me.
I used to give my chilled wort about 20 minutes to settle, then I would auto-siphon it to my fermenter, trying to get the clearest wort I could. But after seeing the Brulosophy experiment, and hearing about the Stone Brewing study, I put it to the test and tried just dumping the whole thing to the fermenter. I liked the results.
I dont dump the whole thing any more, but I also dont do the 20 minute settling wait, and I dont use an auto-siphon any more. Once I’ve whirlpool-chilled to pitching temp, I transfer via pump. My pickup tube leaves about a 1/2" in the kettle, which is mostly hops.
The Brulosophy experiment is just one data point. The Stone Study is just one data point. This new study is just one data point. My personal experience is just anecdotal. The nice thing though is that it’s less work, less time waiting, and I like the results.
Realize what? Homebrewers been pumping out cloudy wort since day 1. Which is a result of repurposed equipment that it’s original intent was not for brewing. Which in this case is good, bad or indifferent.
I dont know about all home brewers, but from my day 1 I was lead to believe, if not outright instructed, to try to get my transferred wort as clear as possible, leaving behind as much trub as possible.
In my brewery, I try to be mindful of quality gains vs effort to achieve them. So in this case, if I save 20 minutes (waiting for settling) and reduce equipment that needs cleaning (auto-siphon) and the end results are no change, or improved… it’s an easy decision. Even if its contrary to proven science or conventional wisdom.
This is one of the great things about home brewing. You can do what works for you. Be a Django Reinhardt!
Maybe this is where my laziness worked in my favor. Like you, I read and heard all the stuff about clear wort and that was my goal and method for quite a while. Then I stooped wprrying about it, based both on ly lack of caring and also some stuff I read. I found that the wort that was cloudy made beer at least as good as clear wort. I guess I’m surprised that more people haven’t gone through the discovery that you and I did.
I never discovered this myself because for the first 10-ish years I brewed I tipped the kettle and poured everything into the fermenter. I was way to cheap to leave liquid behind in the kettle. I definitely read about people doing otherwise, but, these debates always have folks on both sides, so, I never felt alone.
Now, for a few months I have had a Grainfather. GF wort has a lot less trub, but, a healthy amount still transfers to the fermenter. My friends and I like my beer before and after getting the GF.
I think you are mistaking the clarity of clear wort. Clear wort is actually measured in the professional brewery (Kuzne and ‘Narziß provide those numbers). If you are not recirculating for 120+ minutes you are not even close to clear wort. Grain and husk free wort sure, clear professionally clear brewery wort. No, and that makes a huge difference. I would go so far to say the bulk of normal homebrewers wort ( especially biab) would be above the unacceptable mark that brewers use as a “cloudy” wort.
For instance I for one strive for very clear wort. The bottom of my full kettle is easily seen, and during mashing my wort is brilliant. But I mash for 3hrs + and take other measures.
I personally can taste when cloudy wort gets boiled, the resulting wort tastes muddy. The fats and lipids make a difference for me. But then again I can also pick up too strong of a boil as well. So for me and my brewery this is the SOP.
The context here is that professional brewers can have the best of both worlds (potentially). The cloudy fatty wort can help them (potentially) in the fermenter, especially if single infusion, and coagulable nitrogen is down from too strong of a boil. This is also the reason it helps homebrewers, as they usually have more nutrient deficient wort. Then they can filter out the gunk of packaging so it’s not sticking around staling the beer. Homebrewers don’t have that option (usually) but have the benefit of not having to deliver, shake, sit on a shelf warm, and be consumed fast.
Either way it only matters to the person doing the brewing and consuming.
