Lauter clarity and complete hot break removal don't seem to matter for quality

While browsing the "Weihenstephan brewing school" server (again) I came accross a dissertaion that investigated the affect of lauter clarity and hot break removal on the beer quality. Here is the conclusion:

Finally, the investigations presented in this paper
showed that a variation of lauter parameters, particularly
permanent raking in the deep position, caused an increase
of average lauter turbidity, in this case from around 40
EBC to 80 EBC units, which is far above most of today’s
lauter performance specifications. The conclusion was
that not only the raw material quality, but also the applied
lauter techniques and procedures, have an important impact
on the quantity of lauter turbidity. Here, the upper
value of 80 EBC units represents a "worst case" scenario.
This covers all cases that may occur in large-scale production,
even under extreme conditions. Despite the great
increase in lauter turbidity, it may be concluded that the
wort qualities were quite similar, except for a slight but
significant increase of linoleic acid concentration in the
turbid worts. Considering the variation in turbidity, the
differences in wort quality would be expected to be much
greater than what was actually detected by the analytical
methods applied. It appears that particularly the boiling
step, followed by an extensive wort clarification, has an
attemperating effect on differences in wort quality caused
by lauter variations. Neither insufficient spent grain extraction
nor higher iodine values were observed due to
turbid lautering. The fermentation performance, expressed
as extract degradation, pH decrease and ethanol formation,
was increased by turbid lautering as applied, and
yeast vitality appeared to be improved by applying turbid
lautering, even in the 6th fermentation cycle, probably due
to better yeast nutrition. Despite a high lauter turbidity,
the resulting beers did not show filtration problems. In
terms of staling, only a small and insignificant increase of
staling compounds was detected, which is in agreement
with the small increase of linoleic acid in wort due to turbid
lautering. The beers were evaluated as being quite
similar in taste, and for both fresh and forced aged beers,
neither a professional nor a non-professional panel was
able to significantly distinguish "turbid" from standard
beers. The improvement of foam stability for most of the
beers indicates better yeast nutrition due to turbid worts.
In conclusion, not only may fermentation performance
be improved by more turbid lautering but, additionally,
the negative consequences of such a production practice
may be exaggerated, since none of the quality parameters
of the final beers were significantly compromised in this
study. If and when fermentation problems occur in a brewery,
particularly when yeast has already been repitched
several times, a moderate increase in lautering turbidity
should be preferred, since excessively bright worts may
be detrimental to yeast nutrition. When higher lauter turbidities
are occasionally observed due to changes in the
lauter procedure, the risk of decreased beer quality appears
to be minimal.

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Looks like not much, if any, is gained by recirculating until the lauter runs fully clear. And if you get some hot break into the fermenter, no problem, it's even good for the yeast.

Most of this is new to me as well and I can now be less obsessed with these things.
Kai

Interesting.... my first couple AG batches I didn't re-circulate until it ran clear and I never noticed anything horrible, they both cleared up real nice to so no clarity issues IME. I do it now, but if it doesn't matter hey why bother?

Now I can't claim to 100% understand everything in that, I think I missed the part about removing hot break... and further on that subject how would you do so even if you wanted to? Skim it off the top? Guess that's something I don't do.

Kaiser, love the stuff your posting recently... the decoction vid and this. Gets more into the science of it even if I don't change what I'm doing... I like to read about it.

z987k said:

Now I can't claim to 100% understand everything in that, I think I missed the part about removing hot break... and further on that subject how would you do so even if you wanted to? Skim it off the top? Guess that's something I don't do.

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Hot break is the trub you have at the bottom of the kettle at the end of the boil. The flaky stuff that floats around in the wort during the boil.

Kaiser, love the stuff your posting recently... the decoction vid and this. Gets more into the science of it even if I don't change what I'm doing... I like to read about it.

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There is only so much I can do with actually brewing since it takes 4-6 hrs and money for me to brew a batch. I only do this every other week. But I like reading about the science of it and once in a while I come across something that is actually applicable to home breweing.

Kai

so basically, going against conventional wisdom, don't re-circulate and dump the whole pot into the primary, trub and all is a good thing.

z987k said:

so basically, going against conventional wisdom, don't re-circulate and dump the whole pot into the primary, trub and all is a good thing.

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I don't think that to much would be a good thing either. The experiments were done on the order of 5-8 g wet trub to one liter of wort. I think a typical boil yields more on the order of 30 - 50 g/l. It basically means that you can suck in a little of the trub during whirlpooling. If there is to much trub, it will get in the way of the yeast (gumming it up) and the yeast performance should start to suffer.

Kai

The beer is now close to be moved to lagering. It has a very nice noble hop aroma and falvor. Looks like its going to be more of a Pils than a Helles, but that's fine with me. All hops were added before the boil and the beer has an aroma/flavor as if there were any late hop additions.

I do now believe that FWH works.

Kai

For the homebrewer who reads this and considers not performing a vorlauf, whirlpool, and/or other means of clarifying the runnings from the MLT to the kettle, or from the kettle to the fermenter - consider the increased volume loss as a result. Though perfectly clear runnings may not be entirely necessary, and a little hot break in the fermenter won't hurt a thing, I'd hate to lose another few bottles of beer due to trub. Also, more trub means more gunk in the yeast that I may want to save.

This article won't change my procedures, but it adds yet another reason to RDWHAHB.

I am thankful to have the information for my arsenal, but I won't be changing my ways except maybe on the vorlauf. I might just use a colander to catch the big stuff, but I would let the milky stuff come on through for the "yeast nutrition." I will still filter the wort as I am chilling by running through the hopsack (which I have to get a coarser one before next batch due to clogging) so any significantly sized stuff would be removed. I am really looking for clarity into my plate chiller so it doesn't get clogged up. I think since I have taken the hops out of the equation the break isn't going to worry me going through my Therminator. Last time it didn't have any problems... but, that little jewel is a B!TCH to clean if anything gets in it, like hops that won't come out even after 5 cleanings.

I am happy to know about the extra nutritional value of the turbid lauter, and I have never worried about scraping/removing the hot-break like I have heard some do. I was so worried about hop debris, after clogging my Therminator that, I have been focused on preventing that again here of late. Now, I am fighting hop utilization loss due to the hopsack. I have to try the bigger weave bag and then maybe use the smaller weave as a pre-filter for the chiller. I don't know, I have a lot more to try before I am completely happy. Hopefully a larger sack will work and I won't worry again. It is just nice to know if I miss this stuff it doesn't matter other than fermenter space like Yuri said. Thanks Kai, I really like your provided knowledge.:rockin:

Kaiser said:

I don't think that to much would be a good thing either. The experiments were done on the order of 5-8 g wet trub to one liter of wort. I think a typical boil yields more on the order of 30 - 50 g/l. It basically means that you can suck in a little of the trub during whirlpooling. If there is to much trub, it will get in the way of the yeast (gumming it up) and the yeast performance should start to suffer.

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Have you read this article?
http://www.bodensatz.com/homebrew/columns/jirvine/trub.html
Basically it's an experiment with brewing the same beers with varying levels of cold break allowed into the fermenter, and comparing the end result. Since it's cold break, it should contain all the hot break material as well.

I'd be interested to hear your take on that article, especially if you have come across any other references (like the Weihenstephan stuff) that offer more info on the matter. The article was enough to convince me to go ahead and let all the cold break reach the fermenter, so if there is a strong counter-argument I'd certainly like to hear it.

Excellent! So, I'm not being lazy, just using higher lauter turbidities.

If the yeast ain't happy, nobody's happy.