[dmtaylor]

I really think it's the chunks of grain getting boiled.  It happened to me a couple of times when I first started all-grain, and at the advice of homebrewers at the time (this was like 6 or so years ago), ever since I started vorlaufing, I haven't had the problem again, so I really think it makes a difference.  And after a couple of botched batches those many years ago, I don't really care to run experiments skipping vorlaufing to confirm definitively whether it makes a difference!

Sorry, I don't know much about mesh size with different materials.  I can tell you that I buy grain sacks from Northern Brewer and they've been good.  Mesh size seems to have gotten finer over time.  The bags I bought 6 years ago have a rougher mesh than the ones I bought last year, which have a very very fine mesh, probably most appropriate for BIAB which has become very popular over the past year or so.  But mesh size doesn't seem to make any difference in quality, as long as you vorlauf.  If you want to skip the vorlauf, well then... I don't know.

[nateo]

Thanks everyone for all the help. It's given me a lot to think about.

DMTaylor: Do you vorlauf just the first runnings, or the sparge as well? I ask because I usually batch sparge, but would a fly sparge work better once the grain bed is established?

[denny]

DMTaylor: Do you vorlauf just the first runnings, or the sparge as well? I ask because I usually batch sparge, but would a fly sparge work better once the grain bed is established?

Nope, not better, just different.  I still think it's the precrushed grain.  Why not do a batch using other grain and see?  That should be easy.

[dmtaylor]

I am a batch sparger.  You need to vorlauf both the first and second runnings, which is no big deal -- basically, collect the first quart and a half of each of the runnings and pour it back in, then start collecting the clean runnings.  It only takes a minute!  Certainly not worth the trouble of setting up fly sparge -- no thanks.  I know a lot of people love their fly sparge, but I can get up to 90% efficiency with batch sparging, so I see zero benefits in the extra time and equipment needed to fly sparge -- at least for any brewer who's never fly sparged before.  If you got it, go for it, but it's not all some think it's cracked up to be.

[nateo]

Brewing another beer right now. I have vorlaufed (vorgelauft?) for about 2 hours to get the wort clear, but boy is it crystal clear. I think because the grain bed wasn't thick enough to filter well enough? Today has convinced me to construct a proper MLT.

Also, the difference between what my wort currently looks like, and used to look like, is striking. I had no idea I was getting so much grain into my boiler. Like, really, a ton of grain.

[mabrungard]

Brewing another beer right now. I have vorlaufed (vorgelauft?) for about 2 hours to get the wort clear, but boy is it crystal clear. I think because the grain bed wasn't thick enough to filter well enough? Today has convinced me to construct a proper MLT.

Also, the difference between what my wort currently looks like, and used to look like, is striking. I had no idea I was getting so much grain into my boiler. Like, really, a ton of grain.

That is a nice thing about having a RIMS, the constant recirculation produces a very well filtered wort.

[Kit B]

I really don't think bag squeezing causes astringency.  Have you found that it does?

Actually, Denny...To be 100% honest...No.
In recent years, I have read several peoples' instructions stating that it 'could'.
In fact...I've done it several times & never noticed anything negative.
Maybe we can throw that statement out the window.
Has anyone else ever noticed astringency from squeezing your bag?

 

[dbeechum]

Has anyone else ever noticed astringency from squeezing your bag?

Leaving my personal life out of it for a moment, I think the actual problem with squeezing the bag is mechanical lipid release which won't cause astringency, but would cause fatty flavors that could easily spoil into rancidity.

-- Drew

[morticaixavier]

Brewing another beer right now. I have vorlaufed (vorgelauft?) for about 2 hours to get the wort clear, but boy is it crystal clear. I think because the grain bed wasn't thick enough to filter well enough? Today has convinced me to construct a proper MLT.

Also, the difference between what my wort currently looks like, and used to look like, is striking. I had no idea I was getting so much grain into my boiler. Like, really, a ton of grain.

Wow! I don't think you need to vorlauf for that long! ussualy I think you only need to do about a quart or two. You aren't looking for crystal clear wort out of the mashtun just no chunks.

[nateo]

Wow! I don't think you need to vorlauf for that long! ussualy I think you only need to do about a quart or two. You aren't looking for crystal clear wort out of the mashtun just no chunks.

It's not something I plan on doing for all my brews, unless the results are just fantastic. I wanted to try brewing with as little particulate matter as possible to see if the astringency was caused by grain material in the boil, or some other factor. It should be done fermenting in a week or so, and I'll report back with my findings.

One thing I noticed while chilling, the wort had incredible foam stability. I use an immersion chiller, and to finish the last 20* or so to get to pitching temps, I raise and lower the cooler rapidly. It foamed up a lot more than usual, and the foam persisted for a much longer time. Any ideas what would have caused that?

[morticaixavier]

Wow! I don't think you need to vorlauf for that long! ussualy I think you only need to do about a quart or two. You aren't looking for crystal clear wort out of the mashtun just no chunks.

It's not something I plan on doing for all my brews, unless the results are just fantastic. I wanted to try brewing with as little particulate matter as possible to see if the astringency was caused by grain material in the boil, or some other factor.

cool! let us know!

[denny]

It's not something I plan on doing for all my brews, unless the results are just fantastic. I wanted to try brewing with as little particulate matter as possible to see if the astringency was caused by grain material in the boil, or some other factor. It should be done fermenting in a week or so, and I'll report back with my findings.

One thing I noticed while chilling, the wort had incredible foam stability. I use an immersion chiller, and to finish the last 20* or so to get to pitching temps, I raise and lower the cooler rapidly. It foamed up a lot more than usual, and the foam persisted for a much longer time. Any ideas what would have caused that?

Unless you actually have chunks in your runoff, clarity of runoff really isn't related to the clarity or flavor of the finished beer.

[nateo]

Unless you actually have chunks in your runoff, clarity of runoff really isn't related to the clarity or flavor of the finished beer.

How big is a chunk? How much particulate matter / flour is acceptable?

[dmtaylor]

A chunk is macroscopic -- you can easily pick it out by eyesight (20/20 vision).  Acceptable particles, on the other hand, don't look chunky but just cloudy.

By the way..... by vorlaufing for 2 hours, you have basically mashed for an extra 2 hours.  Therefore, I predict your attenuation will be crazy high.  It depends also on the strain of yeast that you have used, and other factors, but this could very well be a really bone dry beer with very very little sweetness.  Might even seem watery.  Just so you're not surprised by it later.  There are reasons why most folks don't mash for that long, and this is a big one.

[nateo]

By the way..... by vorlaufing for 2 hours, you have basically mashed for an extra 2 hours.  Therefore, I predict your attenuation will be crazy high.  It depends also on the strain of yeast that you have used, and other factors, but this could very well be a really bone dry beer with very very little sweetness.  Might even seem watery.  Just so you're not surprised by it later.  There are reasons why most folks don't mash for that long, and this is a big one.

I made a saison, and I hoped for 90%+ attenuation, so I'm not too worried about over-mashing.

I picked up a copy of New Brewing Lager, and found a ton of info, including this: "A lot of draff carried into the kettle is a recipe for astringent beer, but a small amount may improve trub coagulation. The majority of brewers recycle until the runoff is no longer heavily clouded; this is generally accomplished in less than ten minutes. Excessive recycling may lead to greater lipid levels in the wort and ought to be avoided."