[gogreen437]

Still relatively new to all grain brewing, but I have been reading all I can about all grain long before I ever took the plunge and this one caught me off guard.  I apologize if this is a rehash of things that have come up before, but there is a post that I came across on the Northern Brewer Blog called "2 Things Literature Says You Should Do That You Shouldn't."  The second one down says that you should not do a vorlauf as this strips your wort of fatty acids needed for a healthy fermentation.  He elaborates on the point two posts under the initial entry and maintains that the benefits do not outweigh the cons. This is the first time I've read someone advocating not doing a volrauf.  Has anybody experimented with the differences between doing a vorlauf and not doing one and the results?  I'm interested to know if this has any traction, or is a bit of a fringe opinion?  Thanks for any insight.

http://northernbrewer.blogspot.com/2010/03/2-things-literature-says-you-should-do.html

[narvin]

I'm not sure what evidence he has that this could actually have a noticeable effect on beer, but it's definitely a fringe opinion.

Also, in regards to rehydrating yeast, I'd trust Dr. Clayton Cone from Danstar who says that you should rehydrate in water over some guy who works at a homebrew store.

[denny]

I've read that thread on NB and my experience completely disagrees with it.  I've done a vorlauf on every one of my 404 batches and it has caused no problems.

As to rehydration, I know it's the best thing to do but I never do it any more.  I've had no problems from not rehydrationg.

[redzim]

OK so I'm sure a vorlauf doesn't hurt anything... but what does it help? (playing devil's advocate here) Yes I have read in all the literature that it helps settle the grain bed for lautering, keeps chunks of grain out of the kettle, etc.... but I have forgotten it on brew days occasionally, when I was in a hurry and can't say I tasted a noticeable difference later... yes maybe more stuff in the kettle but I leave most hot break in there anyways...  just interested to know why it is so strongly recommended in all the basic all-grain primers.  it's got to be for more than just ease of lautering.

-red

[nateo]

I had a run of 6 very astringent batches. I was able to trace them back to too fine of a crush on my grain, which led to too much draff getting into my boil kettle. After that, I've vorlaufed until my wort was reasonably clear and I've not had the same astringency issues. I've tried vorlaufing until the wort was crystal clear, but didn't notice a difference between "pretty clear" and "really clear" wort in the finished beer.

[tubercle]

Call them up and tell them I said this is just crazy.

 During volrauf I pour back into the mash tun like everybody else. Any fatty acids "stripped" out is going right back in and will be drained during run off. Like it makes a difference. Crazy, just plain crazy.

 I don't rehydrate because I'm too lazy pragmatic and can tell no difference either way.

And as far as HSA during mashing, read up on the amount of O2 a liquid can hold at certain temps. Very soon after volrauf you will be boiling the wort for an hour or so. There is a reason we aerate so our yeast friends can have O2 to reproduce. <sigh>

[tygo]

I return a good amount of grain particles back to the mash tun during vorlauf.  I'm happy I'm not boiling those.  And, as Tubercle said, it's all going back into the mashtun anyway, so I can't really see how I'd  be losing anything important. 

I do rehydrate on the rare occasions I use dry yeast because the stated reasons to do so make sense to me and it's really easy.  If it wasn't really easy I probably wouldn't do it either.

[The Professor]

I've read that thread on NB and my experience completely disagrees with it.  I've done a vorlauf on every one of my 404 batches and it has caused no problems.

As to rehydration, I know it's the best thing to do but I never do it any more.  I've had no problems from not rehydrationg.

I can't comment on the dry yeast issues since I very rarely use it (FWIW, in the very rare instances I do use it ,  I don't rehydrate, and it works just  fine)

As far as volauf goes, I never skip that step and have always done it since I switched to all grain 21 years ago.  I want clear wort going into the kettle, and the vorlauf is the way to achieve that.   I don't put any stock in in the hot side aeration issue mentioned in the page that was linked in the original post.   I'm not saying the guy's science is necessarily incorrect, it's just not the issue he's making it out to be.

I mean, jeez...The hands down best German style lager I EVER tasted (from a pioneering NJ micro in the early/mid 1980's) was made on a practically 19th century  styled system whose wort chiller consisted of cascading the hot wort over a radiator like cooler.  If THAT didn't create aeration issues, then I doubt sincerely that doing a vorlauf is going to cause a problem (especially since the wort is then boiled afterwards).   The beers they made were incredible  (Unfortunately, as is often the case, they were a bit ahead of their time and folded in the early 90's after at least one management/ownership change).

The whole HSA thing is overblown.  I'm not saying that it doesn't have detrimental effect in some circumstances, but as far as vorlauf goes it's  definitely "relax don't worry"   thing...   doing a vorlauf is  not going to harm your beer and it  will more than likely help it..

[tomsawyer]

Its more important to rehydrate the yeast when you are pitching it into a really high sugar wort.  I don't think a yeast is too stressed going into a 1.050 wort dry, its internal salt concentration can compete with that kind of osmotic gradient.  When you get to 1.100, its more difficult for them to pull adequate water and they can sort of partially re-inflate.  They can still do their thing but you are making it hard on them right off the bat.  This is why most winemakers rehydrate their yeast.  They also use a nutrient during rehydration, then feed the yeast some must to acclimate them to the sugar and the temperature.

As for vorlaufing stripping fatty acids, I think they are somewhat soluble in the wort so you wouldn't strip them to an extent that would have an effect on yeast health.

Maybe its just me but I don't ever really get a lot of draff through when I vorlauf.  I'm using Denny's batch sparge setup and I only ever see less than 1/4 cup of solids settling out of the bottom of the pitcher I drain into for vorlaufing.  I've skipped it a time or two and didn't notice any effect, although I do vorlauf as a rule.  I suppose it depends on your lauter tun and crush.

[Kit B]

And as far as HSA during mashing, read up on the amount of O2 a liquid can hold at certain temps. Very soon after volrauf you will be boiling the wort for an hour or so. There is a reason we aerate so our yeast friends can have O2 to reproduce. <sigh>

If HSA was a real problem, most recirculating systems would make bad beer.

[richardt]

I do perform a vorlauf on every batch.  No one likes astringent beer.

Think about it:  why bother keeping your sparge water temps at or below 170F and your pH < 6 during lautering if you're just going to run chunky wort into the boil kettle and let 'er rip at 212 F for an hour or more?  Take the time to set the grain bed by vorlaufing.

I haven't used dry yeast in a while, but I would always rehydrate the batch with pre-boiled water.

[bo]

I do perform a vorlauf on every batch.  No one likes astringent beer.

Think about it:  why bother keeping your sparge water temps at or below 170F and your pH < 6 during lautering if you're just going to run chunky wort into the boil kettle and let 'er rip at 212 F for an hour or more?  Take the time to set the grain bed by vorlaufing.

I haven't used dry yeast in a while, but I would always rehydrate the batch with pre-boiled water.

^^^^^^^^ I agree

[redzim]

Think about it:  why bother keeping your sparge water temps at or below 170F and your pH < 6 during lautering if you're just going to run chunky wort into the boil kettle and let 'er rip at 212 F for an hour or more?  Take the time to set the grain bed by vorlaufing.

Very good point. I'm going to have to do better to remember, and not rush my brew days.

[gimmeales]

Saw this episode too and while a great, entertaining video (as usual), I too, thought the pandering these 'radical' procedures to be silly, unless it was just meant to get a rise out of people.

You can choose to rehydrate dry yeast or not and will make excellent beer either way (I have), but stating the manufacturer is wrong by suggesting hydrating as preferable seems a bit foolish coming from a (admittedly passionate) hobbyist.

HSA does happen, Charlie Bamforth says so, he also says there are so many other factors (namely packaging conditions and storage temps) that contribute to detectable oxidative effects in finished beer, that HSA should not trouble homebrewers or even probrewers that much.  If someone could show me even a semi-controlled experiment of a vorlaufed vs. non-vorlaufed batch, noting fermentation characteristics and flavor impact of finishes beers, I'd take this assertion more seriously.

[lazydog79]

I remember reading that post a while back.  My question was, "Then what the hell do you do with it?"  Like Tygo said, my first run with my system into my pitcher has quite a bit of grain in it.  I wouldn't want to boil it.  I'm probably a little extra thorough, O I vorlauf quite a bit.  I'm not tossing almost a gallon of wort!

On re-hydrating, maybe it was reading that that got me thinking.  I'm a pretty frequent dry user (I'm a cheap skate!), and typically re-hydrate.  Some one on a different board suggested using wort, which is what I do now.  As I'm cooling my wort, I pull out 3 cups or so when it hits 90-ish.  By the time the main body is down to pitching temps, the yeast is already active.  I've had pretty good results with this method - short lags and good attenuation.