Vorlauf and BIAB

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cubalz

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There is no need for a vorlauf when using the BIAB method. When your are finished with your 60 - 90 minute mash. Turn on heat and raise temp to 170f, cut the heat and cover for a 10 minute mash out (optional), pull bag, drain and proceed to boil.
 

LittleRiver

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Vorlauf, mash out, sparging, and bag squeezing are all things that can be safely eliminated from a BIAB process.

If you have an overhead hoist point (highly recommended), at the end of the mash lift the bag and tie it off. Immediately fire the heat for the boil. Let the bag drip into the kettle for the duration of the boil, by which time it will be fully drained (only a cup or so of liquid will remain in the grains). If you have finely milled your grains (~.025") you can easily achieve efficiency in the low 80's with this method.

Coarsely milled grains or a high gravity target (above ~1.065) can cause your efficiency to take a hit, in those cases you may want to add a sparge step.
 

BandonBrewingCo

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And if you don't have an overhead hoist, let the bag sit on an upturned colander or similar in a bucket (or in a huge colander/sieve over the bucket) and that way you can leave the lid closed in the kettle to get to boiling faster. Throw the drippings back into the boil with at least 10 mins to go to sterlise it.

This is what I use from Ikea


 

VikeMan

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If you have an overhead hoist point (highly recommended), at the end of the mash lift the bag and tie it off. Immediately fire the heat for the boil. Let the bag drip into the kettle for the duration of the boil, by which time it will be fully drained (only a cup or so of liquid will remain in the grains). If you have finely milled your grains (~.025") you can easily achieve efficiency in the low 80's with this method.
Are you saying that the total water you are using is your effective pre-boil volume, plus one cup? If so, is this for very low gravity one gallon batches (i.e. tiny grain bills)?

Because if you could really leave only one cup behind with more typical grain bills, mash efficiency would be in the stratosphere.
 

LittleRiver

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@VikeMan your assumptions about batch size and gravity are incorrect.

For 5gal batches at gravities up to about 1.065 I mash with the full volume of water, i.e. no water is reserved for a sparge. I don't sparge at all. I don't recirculate. I don't do a mash out. I don't squeeze the bag, I let gravity fully drain it into the kettle during the entire 1hr boil.

The process is every bit as simple and enjoyable as it sounds, and cleanup is a breeze since there is so little gear to clean. It is effective too, with a mill gap of .025" I consistently get BH efficiencies in the low 80's.
 

VikeMan

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@LittleRiver ok, if you're doing 5 gallon batches, there's a lot more than a cup of wort left behind in your grains. I'm not just talking about liquid you can see pooled somewhere, but also what's been absorbed. If you could actually make that happen (just one cup of loss), you'd be getting mash efficiencies in the very high 90s.
 

LittleRiver

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@VikeMan I've taken a bag that was fully drained by gravity for 1hr, then squeezed it to see what I could get out of it. It was about a cup. That was for a simple grain bill with no adjuncts. I did the same experiment with a recipe that had a pound of flaked oats. I was able to get about a cup and half out of that bag. That's the last time I will ever squeeze a bag. If you can do a gravity drain, squeezing is not worth the effort it entails.

Is there more liquid still in the wet grains even after squeezing? Of course there is, but it's not enough for me to worry about.
 

rjhoff

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Heres an interesting article on sparge vs no sparge: Sparge VS No Sparge - Grainfather Community

“CONCLUSION:
The no sparge beer takes [sic] a big hit on efficiency when compared to the sparged beer and when given to a panel of tasters the majority were able to identify the difference and preferred the sparged beer.
JK was happy with both beers and would drink either though it was very obvious that the sparged beer was better, with a more rounded flavour and better aroma. JK suggests if you’re looking to save time on the brew day you can get away with skipping the sparge step but if you’re looking to make a beer that is better than ‘passable’ then sparging is a very necessary step.“

I‘ve always sparged, first on a 26 gallon three vessel system and now on a 35L Robobrew. On both systems I’d be challenged to fit enough water into the mash and achieve the desired volume out. Also, I don’t typically take steps to speed up my brew day or my fermenting.
 

VikeMan

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Heres an interesting article on sparge vs no sparge: Sparge VS No Sparge - Grainfather Community
So, they made a beer with a post boil OG of 1.060 and another with a post boil OG of 1.045. And the tasting panel preferred the bigger beer, thus declaring "sparge" the winner.

What they actually proved (though it wasn't necessary) is that sparging increases mash efficiency. If only there were some way to make a 1.060 beer without sparging. </sarcasm>
 

LittleRiver

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There's a Brulosophy experiment where they did a much better job of keeping the gravities similar. 14 of 26 testers were able to distinguish the difference between the beers. That result achieved statistical significance, but not by an overwhelming margin (13 were required to achieve significance).

There's an old article by Palmer about no sparge brewing. In that article he's assuming traditional (non-BIAB) gear, and coarsely milled grains. Full volume BIAB with finely milled grains does not need additional grain as he describes in the article. Plenty of us BIABers are able to routinely hit/exceed efficiency targets (for recipes formulated for traditional gear/grind) without adding additional grain, and without sparging. I routinely make 1.065 wort without sparging and without adding additional grain to a recipe.

Regarding taste, I've never done a taste experiment between a sparged and non-sparged batch. Based on my taste impression of the beer I'm making, and the feedback I get from others, I don't have a desire or need to add sparging to my process.

I only sparge if I'm shooting for a gravity above 1.065, because efficiency does take a small hit with the larger grain bills required for big beers.
 

rjhoff

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I don’t have a strong opinion on this and am aware a lot of BIABers don’t sparge (including my son). To your point, @LittleRiver, You should be able to tailor your process and recipes and get good results.
 

VikeMan

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There's a Brulosophy experiment where they did a much better job of keeping the gravities similar. 14 of 26 testers were able to distinguish the difference between the beers. That result achieved statistical significance, but not by an overwhelming margin (13 were required to achieve significance).
I just read that experiment. 14 of 26 tasters doesn't sound overwhelming...hell, it's barely more than half. But the thing is, with triangle testing, if there were no detectable difference, the most likely outcome would be 8 or 9 tasters out of the 26 getting it right. The experiment actually achieved a p value of 0.02, meaning that if there were no actual difference, there was only a 2% chance that 14 (or more) tasters would have got it right. That said, N=1.

I only sparge if I'm shooting for a gravity above 1.065, because efficiency does take a small hit with the larger grain bills required for big beers.
@doug293cz has some cool graphs showing the phenomenon posted around here somewhere. And I built a mash efficiency predictor in my sheet that estimates changes in mash efficiency resulting from changes in grain bill sizes and/or sparge methods (and also taking into account the user's brewhouse parameters). I did that because it's not really very intuitive to (I think) most people, and sure beats guessing.
 

Saunassa

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I have a rope lift with the locking ratchet that hangs above the brew pot. After it hangs for 5 minutes I give it a good squeezing. I use an 8 gallon pot and cannot do full volume mash so I pour the remaining 1 gallon of water through the bag, let it hang and give it a good squeeze. In the winter I may do this as a 10 minute one gallon hot water dunk sparge in a bucket set in house since the garage is so cold. Always get mid 70s or greater efficiency.
 

doug293cz

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...

@doug293cz has some cool graphs showing the phenomenon posted around here somewhere. And I built a mash efficiency predictor in my sheet that estimates changes in mash efficiency resulting from changes in grain bill sizes and/or sparge methods (and also taking into account the user's brewhouse parameters). I did that because it's not really very intuitive to (I think) most people, and sure beats guessing.
Since you mentioned it, here is the chart again. This shows lauter efficiency for different numbers of batch sparges (starting with 0) for two different grain absorption rates. Mash efficiency = conversion efficiency * lauter efficiency, so if your conversion efficiency is less than 100%, then your mash efficiency will be lower than what the chart shows.

Brewhouse efficiency is less interesting than mash efficiency since it is simply:
Brewhouse efficiency = mash efficiency * volume to fermenter / post-boil volume.​
So if your brewhouse efficiency is much lower than your mash efficiency, it's just because you are leaving too much wort behind in your BK and plumbing. Real process problems affect either conversion efficiency or lauter efficiency.

I agree that how efficiency varies with different process variables is not very intuitive, but working thru the math to create this chart (and the spreadsheet that created it) really gave me an in depth understanding of what affects mash efficiency.

Efficiency vs Grain to Pre-Boil Ratio for Various Sparge Counts.png


You can find the spreadsheet here. If you really want to play around with it, you should download a copy as either a LibreOffice or Excel spreadsheet, so you can use the "Goal Seek" tool to do all kinds of interesting things. The sheet takes the following inputs:
  • Grain bill weight
  • Weighted grain potential (in points/lb or %)
  • Grain moisture content
  • Target Post-boil volume (or pre-boil if you set boil time or boil off to 0)
  • Boil off rate
  • Boil time
  • Minimum acceptable mash water to grain ratio (i.e. mash thickness)
  • Grain absorption rate
  • MLT undrainable volume
  • Number of sparge steps (0 - 3)
  • Expected conversion efficiency
The sheet will give you suggested strike and sparge water volumes, which you can override if you wish.

Brew on :mug:
 
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hottpeper13

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I do 5 gal BIAB batches as full volume, and 10 gal as MIAB sparge 3 vessel. I use the same mill settings so I just double the grain bill and get the same eff. What I do have to change is the hop bittering quantity. The sparged batch is also vorlaufed and I fave to cut the 60 min charge by 10% to get the same bitterness. What's up with that?
 

bwible

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And all of these electric brew systems like Grainfather, Robobrew, etc are functionally identical to biab. They just use a basket to hold the grain instead of a bag. Most of them provide instructions to brew with a sparge step or no sparge step.
 

bwible

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@LittleRiver ok, if you're doing 5 gallon batches, there's a lot more than a cup of wort left behind in your grains. I'm not just talking about liquid you can see pooled somewhere, but also what's been absorbed. If you could actually make that happen (just one cup of loss), you'd be getting mash efficiencies in the very high 90s.
I think you are correct. Search “all grain absorbtion rate”. Its largely agreed on at about .12 gallons per pound. .12 in fractions is an eighth. And a pint just happens to be an eighth of a gallon. So we lose about a pint of water/wort per pound of grain to absorbtion. To me, this is a good case for sparging.
 

rjhoff

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And all of these electric brew systems like Grainfather, Robobrew, etc are functionally identical to biab. They just use a basket to hold the grain instead of a bag. Most of them provide instructions to brew with a sparge step or no sparge step.
Yes, the mash concept is the same, plus most have an integrated pump for recirculating and racking - very nice convenience, and electronic temperature control, which is effective at maintaining the mash temperature.
 

bwible

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Yes, the mash concept is the same, plus most have an integrated pump for recirculating and racking - very nice convenience, and electronic temperature control, which is effective at maintaining the mash temperature.
The big difference is they recirculate during the mash while the grain is fully immersed. There is no recirculation back through the grain once the basket is lifted. So this is not the equivelant of a sparge or vorlauf step. Recirculation through the immersed grain on an electric system is mostly done to maintain a constant temp throughout and avoid hot spots around the heating elements.
 

rjhoff

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The big difference is they recirculate during the mash while the grain is fully immersed. There is no recirculation back through the grain once the basket is lifted. So this is not the equivelant of a sparge or vorlauf step. Recirculation through the immersed grain on an electric system is mostly done to maintain a constant temp throughout and avoid hot spots around the heating elements.
Yes true and I wasn't trying to imply it was helpful in a sparge. I always sparge with my Robobrew, usually in the neighborhood of 2.5-3 gallons, mash pipe raised and pump off. I also believe that recirculation during mash has the potential to extract more sugars.
 

doug293cz

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Yes true and I wasn't trying to imply it was helpful in a sparge. I always sparge with my Robobrew, usually in the neighborhood of 2.5-3 gallons, mash pipe raised and pump off. I also believe that recirculation during mash has the potential to extract more sugars.
At best recirculation can speed up conversion a bit. This may allow better conversion efficiency in cases where conversion is incomplete at the end of the allotted mash time, so you get more conversion in the same amount of time. You can get the same level of conversion by extending the mash. Using a finer crush has an even larger effect on speeding up the conversion rate. You can get 100% conversion with any of these methods with the appropriate length mash, provided the enzymes aren't all denatured before the end of the mash.

Basket and malt pipe systems have an issue that affects lauter efficiency, because the wort outside the basket/pipe is of lower SG than the wort within the basket/pipe. If this isn't mitigated before, or as a part of, lautering, the lower density wort drains freely, and the wort retained due to grain absorption is the higher density wort. Thus more sugar is retained in the grain mass after lautering, and lauter efficiency is lower. Recirculation will homogenize the wort under the basket/pipe with the wort inside, but will have limited effect on wort in the lateral space between the basket/pipe and vessel wall. The effect will be worse for a pipe than a basket, and depending on flow patterns, there may be no effect for a basket. The better the wort is homogenized before lautering, the higher the lauter efficiency will be.

Brew on :mug:
 

doug293cz

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I think you are correct. Search “all grain absorbtion rate”. Its largely agreed on at about .12 gallons per pound. .12 in fractions is an eighth. And a pint just happens to be an eighth of a gallon. So we lose about a pint of water/wort per pound of grain to absorbtion. To me, this is a good case for sparging.
0.12 gal/lb is the typical absorption rate for a drained MLT. Since a suspended bag applies some compression to the grain mass, it will typically have a lower absorption rate - 0.10 - 0.08 gal/lb, or even lower, depending on draining time. Squeezing the bag can drop absorption to 0.08 - 0.04 gal/lb. Reducing grain absorption increases the lauter efficiency, and can partially make up for the efficiency lost due to not sparging (see the chart posted previously in this thread.) BIAB systems, particularly if they don't recirculate, can employ a much finer grain crush than other systems, and can often get higher conversion efficiency. The lower grain absorption, combined with higher conversion efficiency, often allows BIAB systems to obtain mash efficiencies equal to sparged traditional systems. There are many anecdotal accounts from BIABers on HBT who found they didn't need to make any adjustments to grain bills (to compensate for lower efficiency) when moving to BIAB.

Brew on :mug:
 

Bobby_M

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Heres an interesting article on sparge vs no sparge: Sparge VS No Sparge - Grainfather Community

“CONCLUSION:
The no sparge beer takes [sic] a big hit on efficiency when compared to the sparged beer and when given to a panel of tasters the majority were able to identify the difference and preferred the sparged beer.
JK was happy with both beers and would drink either though it was very obvious that the sparged beer was better, with a more rounded flavour and better aroma. JK suggests if you’re looking to save time on the brew day you can get away with skipping the sparge step but if you’re looking to make a beer that is better than ‘passable’ then sparging is a very necessary step.“

I‘ve always sparged, first on a 26 gallon three vessel system and now on a 35L Robobrew. On both systems I’d be challenged to fit enough water into the mash and achieve the desired volume out. Also, I don’t typically take steps to speed up my brew day or my fermenting.
I agree with the others that peg this as unscientific. You dont compare two beers with that large of a gravity and ABV difference and falsely attribute the preference to the PROCESS. This is so obvious.

Sparging is often a necessity IF the goal is high efficiency but it comes at the cost of time, complexity of equipment, and also sometimes pH drift into unsavory territory. If you dont account for it, or dont get lucky, it can tank your quality.
 

Hwk-I-St8

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The big difference is they recirculate during the mash while the grain is fully immersed. There is no recirculation back through the grain once the basket is lifted. So this is not the equivelant of a sparge or vorlauf step. Recirculation through the immersed grain on an electric system is mostly done to maintain a constant temp throughout and avoid hot spots around the heating elements.
For systems that have a "malt pipe" where the basket has solid sides, it's a pretty good equivalent of a vorlauf with the recirculation. You're still getting the filtering of the grain bed and lifting the basket out is really not any different from draining the liquid out. All the wort has been through the grain bed and is filtered by it.
 

Hwk-I-St8

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At best recirculation can speed up conversion a bit. This may allow better conversion efficiency in cases where conversion is incomplete at the end of the allotted mash time, so you get more conversion in the same amount of time. You can get the same level of conversion by extending the mash. Using a finer crush has an even larger effect on speeding up the conversion rate. You can get 100% conversion with any of these methods with the appropriate length mash, provided the enzymes aren't all denatured before the end of the mash.

Basket and malt pipe systems have an issue that affects lauter efficiency, because the wort outside the basket/pipe is of lower SG than the wort within the basket/pipe. If this isn't mitigated before, or as a part of, lautering, the lower density wort drains freely, and the wort retained due to grain absorption is the higher density wort. Thus more sugar is retained in the grain mass after lautering, and lauter efficiency is lower. Recirculation will homogenize the wort under the basket/pipe with the wort inside, but will have limited effect on wort in the lateral space between the basket/pipe and vessel wall. The effect will be worse for a pipe than a basket, and depending on flow patterns, there may be no effect for a basket. The better the wort is homogenized before lautering, the higher the lauter efficiency will be.

Brew on :mug:
Doug, not sure I agree with your second paragraph. With a malt pipe (solid sides), if you recirculate and return back into the pipe, drawing off the bottom will pull from both the sides and the pipe. I would not expect the liquid on the sides of the pipe (between the pipe and the kettle wall) to just sit dormant. Wort will flow more easily through that passage than it will down through the grain, so I'd expect wort drawn off the bottom to at least partially consist of wort from that space. Over an hour long mash with recirculation, I'd expect the wort to be pretty consistent with respect to gravity throughout the system. What am I missing?
 

doug293cz

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Doug, not sure I agree with your second paragraph. With a malt pipe (solid sides), if you recirculate and return back into the pipe, drawing off the bottom will pull from both the sides and the pipe. I would not expect the liquid on the sides of the pipe (between the pipe and the kettle wall) to just sit dormant. Wort will flow more easily through that passage than it will down through the grain, so I'd expect wort drawn off the bottom to at least partially consist of wort from that space. Over an hour long mash with recirculation, I'd expect the wort to be pretty consistent with respect to gravity throughout the system. What am I missing?
The wort between the pipe wall and kettle wall doesn't really participate in the recirculation. Read this thread.

Brew on :mug:
 

Oginme

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Having checked the difference in gravity between the wort outside the pipe versus work inside the pipe, I can attest to the large differential between the two which Doug293cz has referenced. The liquid outside the pipe gets a slow migration of the sugars due to the difference in concentration between the bottom of the column and the top, but this is a very slow process. I measured over several brews and found a wide range depending much upon the gravity of the wort. The differential was greater as the wort gravity went up. For a session type ale, I saw a gravity of 8.1 brix coming out of the recirculation line on my 6.5 G Anvil Foundry. The wort outside the mash basket had a gravity of 4.6 Brix with both readings being taken after a 60 minute mash. On a higher gravity IPA, the wort in the recirculation line measured 10.4 Brix and outside the mash basket the wort was only 5.8 Brix, again after a 60 minute mash. I can project that that differential would be much greater with the taller 10.5 gallon version of the Anvil Foundry.

While you may think that the liquid would be drawn down evenly between inside the basket and outside the basket, the added volume to the top of the mash pipe accounts for the preferential flow of wort through the basket (as was designed) rather than from the sides.
 

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The wort between the pipe wall and kettle wall doesn't really participate in the recirculation. Read this thread.

Brew on :mug:
Wow, interesting thread and quite surprising to me. I just got a basket (very cheap) from brew boss and was planning to line it with SS to create a malt pipe, but maybe I'll go with a more COFI like solution instead.
 

Nubiwan

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Vorlauf, mash out, sparging, and bag squeezing are all things that can be safely eliminated from a BIAB process.

If you have an overhead hoist point (highly recommended), at the end of the mash lift the bag and tie it off. Immediately fire the heat for the boil. Let the bag drip into the kettle for the duration of the boil, by which time it will be fully drained (only a cup or so of liquid will remain in the grains). If you have finely milled your grains (~.025") you can easily achieve efficiency in the low 80's with this method.

Coarsely milled grains or a high gravity target (above ~1.065) can cause your efficiency to take a hit, in those cases you may want to add a sparge step.
A little bag squeeze never hurt anyone.... I squeeze mine all the time.
 
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