Author: Matt Waldron
In my quest to make better beer as cheap and as fast as possible, I’ve toyed with many variables in my brewing, particularly since transitioning from batch sparge to Brew In A Bag (BIAB). One such variable is the vorlauf step, which involves gently transferring sweet wort from the bottom of the mash back into top of the tun with the goal of setting the grain bed and clarifying the sweet wort that gets sent to the boil kettle. Commonly performed at the conclusion of the mash just prior to running off, many accept the vorlauf as essential to avoiding unwanted astringency caused by tannins leeched from the grains as well as producing a clearer beer. However, there’s been some chatter lately about the potential meaninglessness of this step, with some claiming the process eliminates too minimal an amount of grain to have any positive impact.
Back when I used the batch sparge method, I would vorlauf because it’s what I learned to do and didn’t really complicate things. Then I moved to BIAB where full volume mashes and removing spent grains from the sweet wort (instead of the other way around) was believed by many to make vorlaufing an unnecessary step. Really? I wondered about the extent to which a vorlauf would effect the perceptible characteristics of my finished beer, whether it resulted in a quality improvement or if I’d been performing a meaningless method purely out of an appeal to authority? Time to take a closer look!
| PURPOSE |
To evaluate the differences between 2 batches of the same beer where one had the vorlauf step performed at the end of the mash while the other did not.
| METHODS |
To get a good idea of the impact of vorlaufing, I opted to brew a clone of Firestone Walkers’s very pale and brilliantly clear Pivo Pils, managing to get everything the recipe called for except floor malted German Pilsner malt.
Recipe Details
| Batch Size | Boil Time | IBU | SRM | Est. OG | Est. FG | ABV |
|---|---|---|---|---|---|---|
| 5 gal | 90 min | 36.6 IBUs | 2.9 SRM | 1.050 | 1.011 | 5.1 % |
| Actuals | 1.048 | 1.01 | 5.0 % | |||
Fermentables
| Name | Amount | % |
|---|---|---|
| Pilsner (Weyermann) | 9 lbs | 100 |
Hops
| Name | Amount | Time | Use | Form | Alpha % |
|---|---|---|---|---|---|
| Magnum | 15 g | 60 min | First Wort | Pellet | 12 |
| Select Spalt | 28 g | 10 min | Boil | Pellet | 4.8 |
| Select Spalt | 28 g | 5 min | Boil | Pellet | 4.8 |
| Saphir | 57 g | 5 days | Dry Hop | Pellet | 3.5 |
Yeast
| Name | Lab | Attenuation | Temperature |
|---|---|---|---|
| Bohemian Lager (2124) | Wyeast Labs | 71% | 48°F - 58°F |
Download
| Download this recipe's BeerXML file |
I chose to use the vitality starter method for this xBmt and my brew day began with me pitching 2 packs of Wyeast 2124 Bohemian Lager yeast into 2 liters of starter wort then allowing it to spin on a stir plate while I brewed.
I proceeded to measure out and mill two equal sets of the same grain. The batches were brewed back-to-back and treated exactly the same with the exception of the variable in question. Both batches were mashed at the schedule written in the recipe. As I began heating to mashout, the non-vorlauf batch was left alone while the other batch had approximately 9 gallons of sweet wort pulled from the bottom of the tun and gently placed back on top of the mash. My brewer-wife Marie performed this process slowly and evenly to avoid channeling or disturbing the grain bed.
The vorlauf process was relatively simple and required only slightly more effort than not vorlaufing. The bag was then removed and the wort boiled for 90 minutes with hops added according to the recipe. At the conclusion of the boil, I chilled the wort and took hydrometer readings that revealed a slight difference, with the non-vorlauf batch coming in at 1.048 SG while the vorlauf batch was sitting slightly higher at 1.050 SG.
Left: non-vorlauf 1.048 SG | Right: vorlauf 1.050 SG
Differences in color and clarity were easily discernible at this point. Given each batch was made with identical ingredients on the same system, the only thing I can think of to account for this difference is the vorlauf step. I was very curious to see how this might change throughout the fermentation process. Both fermentors were placed in my temperature controlled chamber and left to finish chilling to 58°F before I evenly split the starter between them. Fermentation was ripping along within 24 hours and I noticed the non-vorlauf batch possessed a larger, thicker, and darker krausen. Interesting.
Utilizing the quick lager method, I gently began to ramp the temp after a few days of active fermentation then let the beers sit warm to ensure complete attenuation and clean up any undesirables. By 2 weeks in, both batches had had been ramped down to lager temp. I was expecting them to be a bit more similar at this point, but that didn’t appear to be the case, as the vorlauf batch looked much clearer and darker than the non-vorlauf batch. I let the beers lager at 34˚F/1˚C for 10 days before I hit them with the dry hops. Five days later, I fined each batch with equal amounts of Biofine Clear and let them sit for 36 more hours. Still unhappy with the clarity, I dosed each with a tad more Biofine to try to push it along then proceeded to package 12 hours later. A hydrometer reading at this point revealed both beers finished at 1.010 SG, putting the vorlauf batch at 5.3% ABV and the non-vorlauf batch at 5.2% ABV.
Left: non-vorlauf 1.010 SG | Right: vorlauf 1.010 SG
I racked the beer to kegs and placed them in my kegerator where they were force carbonated. Unfortunately, my attempt to reproduce the beautifully clear Pivo Pils had failed, as the beers maintained a hazy appearance. However, they were tasting pretty damn good when it came time to collect data.
Left: non-vorlauf | Right: vorlauf
| RESULTS |
I collected data for this xBmt just prior to the start of the Miami Beer Fest, as I’d arrived early to set things up and wanted to catch tasters with fresh palates. Participants included 44 craft beer enthusiasts, professional brewers, brewery staff, and homebrewers. Each taster was blindly served 1 sample of the vorlauf beer and 2 samples of the non-vorlauf beer then asked to select the one that was different. In order to achieve statistical significance with this sample size, 21 participants (p<0.05) would have had to accurately identify the vorlauf sample as being unique. In the end, 20 tasters (p=0.063) made the correct selection, suggesting this pool of participants was not capable of reliably distinguishing between the vorlauf and non-vorlauf beers.
Since the results failed to reach significance, the following information should be interpreted with caution, as it is potentially meaningless. The 20 participants who were correct on the triangle were subsequently instructed to complete a brief evaluation comparing only the 2 different samples. When asked about preference, 8 reported preferring the non-vorlauf sample, 3 said they liked the vorlauf beer more, 7 had no preference despite perceiving the beers as different, and 2 felt there was no difference between the samples. Tasters were then instructed to select the sample they thought was produced using the vorlauf step, each sample got 10 votes.
My Impressions: I perceived the non-vorlauf beer as having a grainy, Pilsner malt driven aroma that tamed the hops while the flavor was a bit breadier with early carbonated samples having slightly more body. The vorlauf beer let the hops fly a bit more and had a cleaner flavor with a slightly crisper mouthfeel. The differences were slight, but knowing what I was looking for, I was able to accurately identify the different beer in multiple triangle tests. In the end, I preferred the vorluaf beer due to the crisper sting and aroma from the hops, and its clarity is an aesthetic thing that plays to my overall enjoyment.
| DISCUSSION |
Performed as a matter of course by brewers of all methodical ilks, the vorlauf is presumed by many to reduce the risk of tannin extraction from grain bits making it to the boil. However, despite how easy it is, some have begun to question whether vorlaufing actually makes a difference on the homebrew scale, with many who have ditched the process claiming no negative effect. Indeed, the results from this xBmt support the doubters’ notion, as participants were unable to reliably distinguish a beer produced with a vorlauf from one made without it.
While the comparative analysis completed by those who were accurate on the triangle test is statistically junk, I found it interesting enough to comment on. Grain of salt alert! I’m big believer in the adage my grandmother taught me that if something doesn’t look good, no one will want to put it in their mouth (pretty sure she was referring to consumables), and as they say, we taste our eyes first. But our participants are served samples in opaque cups, meaning they have only their noses and tongues to rely on. The fact a larger portion of tasters preferred the non-vorlauf sample really caught me off guard and made me wonder if some might have been swayed had the samples been served in clear glasses, the clarity perhaps biasing their preference.
Being that this is only a single point of data, I’d caution against making any absolute conclusions. As for me, since vorlaufing did give an extra edge on my efficiency and seemed to squeeze out a bit more clarity, I plan to continue doing it for now… at least until results from future xBmts suggest something different.
Do you vorlauf or have you decided it’s not worth the time? Feel free to share your experience, thoughts, and questions about vorlaufing in the comments section below!
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It seems to me that serving in opaque cups eliminated the effect of the variable in question.
It certainly eliminates the impact of appearance on distinguishability, which is the reason we use them.
Nathan, if we were testing clarity, sure. The point was to see if it made a discernible difference in the flavor of the beer though, so I think things tracked well. We can visibly see the clarity…no need to run experiments there, but we do need to find out what it might have been in the end. The P was SOOO close, I think it bears repeating.
Okay, makes sense. From your picture it is hard to tell which beer is clearer in the glass, though. I am interested in the clarity difference if both beers tasted the same, as, everything else being equal, I would prefer clearer beer.
What is interesting to me is that in the truby vs. non-truby experiment, truby came out clearer, whereas here the non-vorlaufed beer came out hazier. Do you have any hypothesis for why different types of solids into the wort result in a different clarity outcome?
I think you re confounding boil runoff with vorlauf which is end of mash, not boil.
More permiable particles washed into the wort could be one guess…and just a guess.
It’s my understanding that drawing off a few quarts is meant to set the bed and remove any shredded husk material that is on the bottom of the tun, thus otherwise when boiling that husk may lead to excess tannin extraction, and unless the bed is set a stuck sparge results.
The photo shows the use of a fabric filter, and you state that both brews were treated exactly the same, so I’ll assume that there were no husks in either beer. And since you used a filter there is no chance of channeling, unless you did a low WTGR in one and not the other – which makes the vorlauf step (in this case) unnecessary – but something had an affect on color.
I’ve begin to wonder about mashing out while in the tun, which unless recirculated must burn (change) the bottom layer of wort to some degree. This also happens when attempting to regain a lost degree or two while mashing.
The color distinction could be a result of the mash out step. In one case the heated bottom layer was pulled and added back to the top, but since you don’t say if you used full volume mashing, that may not be relevant, meaning if sparged the drawn portion never made it into the boil kettle. In the non-vorlauf that layer went straight into the boil kettle.
I agree with most of that. Channeling and everything is a bit of a no go on BIAB volume, but drawing wort through the bag apparently cleans up the beer, probably due to less huskiness.
Were you happy with either beer? If not, perhaps try again when one of the beers is up to your standards. How did the tasters score the beer?
Did you use irish moss, Yeast Nutrient, Fermcap, or Oxygen?
It would be interesting to see what the pH was in both of them at various points in the process (mid-mash, post vorlauf, pre-boil, post-boil, post-ferment).
John,
Beers were both good though I had a preference for the vorlaufed beer. My issue came from the clarity which COULD be due to Biofirm being worse at dropping out hop matter. We shall see as I carry things forward, no promises on a xBmt though.
I used a Ph stabilizer so they have routinely hit 5.2 ph. Did not drop in Irish Moss, though that might have helped (missed it on the first one so had to skip it in the second). Since it was a 5% beer design, I did not use a yeast nutrient since I was pitching a starter. No fermcap and I’m still just hand shaking for oxygen intake.
Its not my habit to track Ph like that, though that might be interesting.
This is in reply to Matt, but there was no “reply” button in his response.
If by mash pH stabilizer you mean the “5.2” product, I recommend you do some research. It’s only benefit seems to be adding a bunch of salt to your beer- this is according to the water gurus who wrote the book. There are many, much easier ways to (properly) adjust your mash pH.
John – thanks for your note. I’ve gotten this more than once, but as I said in a reply earlier, with my ground water and through my brews I’ve never really had my Ph skew crazy using the 5.2 mash stabilizer. I realize that some people want me to “show my work” with all the water chemistry I’ve done, but it’s basically a simple filter on groundwater that is great for brewing 98% of the year.
I brewed pretty much this same beer earlier this year. I didn’t dry hop cold so I can’t say that wasn’t what caused clarity issues. I did dry hop and got this to be brilliantly clear. Could very well be the lack of whirlfloc. I’ve seen that with other beers before.
Did you actually measure the pH in the mash with a meter or are you assuming that 5.2 sets the pH at 5.2?
You would be surprised how much the pH changes throughout the process.
I would guess that since this beer is fermenting colder it would be better with nutrients and O2.
Could be the case. I plan to get to the bottom of this one, don’t you worry. And yes, I could chase the Ph all the way through, nor am I a skilled enough beer chemist to dial it right back when it went off. Simply that, when using the Ph Stabilizer on smaller beers like this, over a dozen batches when I did check my mash Ph, it came in between 5.1 and 5.3 every time, so, in time, I stopped checking.
I don’t know why the sub-thread “reply” button is missing only in this thread but-
If you are getting a stable mash pH with the “5.2” product, you might try not using it altogether. Malts have their own built-in buffering strategy that can deal with most “normal” water profiles, even though a slightly acidic one is preferred for max eff. If you know your water is heavily skewed one way, or the other, there are simple additions that can more effectively correct the situation without adversely affecting the flavor of your beer. I don’t worry too much about it, and prefer the “less is more” strategy. If you really want to improve your local water, the science says to correct specifically for the local condition, and not to use some snake oil that can magically correct for every condition- acid or basic. The $$$ solution is to get an RO system, and build your own water for each specific style, if it bothers you that much.
Bo, you can get RO water from most grocery stores (at least ones that I’ve seen in the few states I’ve lived in). Here I can get RO water for $0.24/gallon, much cheaper than buying my own RO system. The salts I add are also dirt cheap, pennies for each addition. My tap water tastes pretty good as it is, but switching to RO+salts really made a huge difference in the taste of my beer.
I just did a wheat beer where I didnt vorlauf at all… my garage was cold sue me lol. Now are not wheat beers notorious for stuck sparges? Mine never did despite never having “set the grain bed”.
Im convinced most of these things we do either 1. dont matter on a homebrew scale 2. are just bullshit to begin with.
I tend to believe SOME of it is dogma or traditional, SOME of it is true with particular situations/methods/scales/ ingredients.
Great article. One question about your process. After you vorlaufed, did you still pull the bag and then transfer the wort, or transfer and then pulled the bag? Thanks!
Hey Jeff. In BIAB, you pull and drain the bag to then do a boil. I did that in both batches. Boiling your grain the whole way is not something I think would work out.
I think Jeff was wondering if you pulled your sack, then recirc’d/vorlaufed through your (now) draining sack. This does far more filtering than just getting rid of any husks/grain that may have snuck out, and would more closely simulate a vorlauf in a regular lauter tun. Using a boiling/steaming basket to hold your sack while draining makes doing this much easier. Just pulling your sack out, and more so, squeezing it, usually results in much milkier wort from the extra “flour” in the kettle that easily passes through voile. With extra care (more than if a vorlauf was done), much of the flour/trub can be left behind in the kettle; but it’s been boiled by that point, and the damage may have already been done. I’m usually not that concerned about clarity (I squeeze, twice), and adding two vorlaufs (I do a dunk sparge) isn’t worth it to me for most of my beers.
Thanks Bo. I understand that there are a lot of ways to approach this and a lot of ways to do it, but on my system, the only clean, sure way to get it was to have a constant outflow and just cycle the wort from measured pitchers back up into the wort. And it seemed to have an effect. Good point on the basket. If I was doing to add a new piece of kit, that is high on my list.
Interesting. I agree, appearance is a big part of beer, so I would be interested in the results if the beers were served in glasses, as long as the glasses are not labelled.
It is also interesting to think about what flavors are getting lost in the various methods of clarifying and filtering beer. We normally think of clarity as a good thing no matter what.
Yeah, it puts out an interesting point that I think we see with Macro Brewing. In an attempt to make a beer that looks great on TV, are we losing potential flavor? Prime example being unfiltered Hefe vs. German Hefe vs. American Wheat beers.
That said, people do “taste with their eyes” and sometimes, when you want that clean crisp Pilsner taste…it really does the trick.
Thanks for doing this. I’ve been doing MIAB for as long as I’ve done AG, and I’ve never actually done a vorlauf. It sounds to me like I’m not missing out on much, but if I wanted a clearer beer or a stronger hop flavor it might be a simple tweak to move it up a notch.
I think most everything has a minor effect on a beer. Brewing it “your way” is really dialing all those things in to make what makes you happy.
Well this really helps me… I too like my beers to look brilliant. Thanks again Marshall for this post as I have been curious about this step since I started all grain 2 years ago. I am going to order a shirt now to support your efforts !
“Both batches were mashed at the schedule written in the recipe.” am I blind? I’m not seeing a mash schedule. Did you go with a protein rest?
Also.. Did you add Irish moss to the kettle?
Finally, it says “we taste our eyes first”, which I got a chuckle out of. 🙂
Sorry, here ya go:
Yeasts Used
Amt Name Type # %/IBU
1.0 pkg Bohemian Lager (Wyeast Labs #2124) [124.21 ml] Yeast 7 –
Mash Steps: (Brynildson insists this schedule is essential for getting the dry, crisp body that supports that huge dry hop shot of Saphir hop so well.)
Step
Target Temp
Time
Protein Rest
122.0 °F
20 min
Saccharification Rest
145.0 °F
60 min
Saccharification Rest
155.0 °F
20 min
Mash-Out
168.0 °F
10 min
The clarifying effect might also be addressable by changing the clarifying agent (I’ve not used either, but I’ve read that gelatin works more quickly than bioferm)
I do BIAB and started doing recirculation/vorlauf at the end of my mash, while turning the heat up. I pull out about a gallon a minute and pour it back in. This gets done about 15 times in the time it takes to get to 165F (at which point I lift the bag and let it continue to drain until the mash has reached boiling).
I am NOT gentle in the recirculation process. I don’t mind disturbing that grain bed because the BIAB bag is filtering out the large husks. I’m trying to get maximum sugar extraction.
What I’ve discovered by brewing batches with and without this method is that I ALWAYS get slightly higher efficiency when I do a recirculation and my efficiency seems to be slightly more reliable, even with “sticky” grists with lots of rye or flaked oats/wheat.
Your experiment results line up with mine, in terms of getting slightly better efficiency by doing the recirculation. I think that might be the best reason for BIAB brewers to use this technique, whether or not they get clearer beer.
I’m fairly new to BIAB, but when searching for ways to improve my efficiency, several comments I saw on forums suggested whisking the grain vigorously immediately before removing the bag. I wonder if this has the same effect as your recirculation? I don’t have a valve on my kettle, so I can’t recirculate, but I’m going to try giving the grain a stir before removing on my next brew.
Fun to note that this is one of those steps that gets hazy with word usage. When I talked about “recirculation” initially, I was thinking of it as a full batch rotation of wort volume to do much of what a vorlauf does. However, I did not thin of it as vorlauf as that is something I associated with fly/batch sparging. So, we had to come to a consensus on what to use as “recirculation” to many folks would mean that I had a pump on my keggle system and I was recirculating the wort the whole time.
Just FYI – I’d really suggest getting a valve on your kettle or keggle. Its one of those little steps that can change your brew day and options for the better once you put a little bit of cash into it.
Matt
Chris – Thanks for the feedback. The only reason I would say I take it easy it to avoid splashing and remove that variable from the xBmt. Thanks for your input, helps to know who else has tried it.
There seems to be a lot of talk (over on the reddit board) about vorlaufing increasing efficiency. I’m skeptical that for BIAB (or batch sparge) it does anything more than a good stirring/agitation would do- which many people seem not to do, or at least mention they used to do before getting the increased eff by vorlaufing. Many “experts” recommend several stirrings during a typical mash.
If you’re really wanting to increase the efficiency of your BIAB, one of the only ways (that obeys the laws of physics) is to reserve some liquor, and do a “dunk sparge”. This assumes you don’t want to “squeeze” so as to keep your wort clearer. Most of the BIAB programs support it, or just use a “batch sparge” formula, which is all BIAB is, even when only doing a single batch/no sparge”. It dirties one more vessel, but almost anything that can take ~150F can be used- 5 gal bucket, food tote, extra kettle, etc. You’d have to vorlauf again, if you swing that way, but that’s the price of increasing efficiency to save that $1.29 in extra grain.
And adding more grain or not doing it could be fine for the way you’re dialing in the beer. The recipe listed was stirred every 15 mins as I’m wont to do when brewing. I set a time that reminds me to be sure and give everything a good look over. So, while it was stilled, it wasn’t done so in any crazy manner and I certainly did not dunk sparge. As we noted, it had a small effect on the efficiency and color in this xBmt and it was a minimal amount of effort that I think I’ll keep doing (as long as I remember to do it.) Nobody is saying you’re a bad brewer if you don’t do it…just that it might have a mild effect, though not one that past our statistical significance threshold.
It’s interesting that you stirred several times, and still got an increase- however modest. Theoretically, it shouldn’t matter that much as log as everything was homogonized after your last stir. Conversion Efficiency, the true indicator, can be easily checked during the mash before/after each stir.
I was commenting more on brewers who never stir, then report massive efficiency gains from “vorlaufing”, when they are really just implementing a “stir” they had never done before, due to fear. Many fly spargers, and even some batch spargers, are afraid of disturbing the grain bed, when, in actuality, it can be re-established fairly easily after a stir.
I stirred a bunch prior to removing bag and found that I gained more efficiency compared to not stirring at all. I guess stirring has the same effect as recirculation.
I do like the concept of this Exbeeriment but I think using BIAB method was not the best choice.
I use no vorlauf with the batch sparge method. Only a stainless mesh filter for the first few seconds of runnings to catch any grains that make it past my mash tun screen. I can produce crystal clear, commercial clarity beers this way, along with gelatin 🙂
I think Marshall could do this again with his double mash tun setup and batch sparge, and then send me some of the beers so I can evaluate them! 🙂
Hi John. Thanks for the input. While I agree that the BIAB method makes is a DIFFERENT experiment, I think it is very valid for people brewing that style and provides a little more insight into to why the vorlauf does/does not matter at our level of brewing. I think it would be an interesting xBmt in a Batch and Fly sparge system to see where it makes the biggest difference. In that case, my bias/guess would be the old fly-sparge guys would see the biggest difference leaving it out.
Looks like the gelatin vs. biofine is a serious enough consideration that I may have to look into it further.
Also, we encourage everyone to share how they brew and what works for them, so don’t think I’m saying “this is the way to do X” in any article I write. (If Marshall has not bashed that out in an edit) We’re simply experimenting with our methods in our systems to see how it effects results and can add to the knowledge pool. You input on no-vorlauf with batch sparging with the addition of a bit of equipment is also viable. Have you tried a with and without batch of your “go to” beer to check for differences?
Thanks for the article. My experience with BioFine is that it has to be thoroughly mixed into the beer. I’ve learned that adding it while kegging seems to be the best way. Adding it to the fermentor and swirling never seem to give me the same effect. Gelatin does work better for hoppy beer though.
Good point. I think I’ll be reaching out to the makers of BioFine to get their input on the best use and if they feel it should be 100% as effective as gelatin.
I also need to answer my questions — What exactly do you do to cold crash a lager? (since it could be sitting near freezing for a week or two anyway.)
Great experiment.
I am going to incorporate this vorlauf into my brewing method (half batch stove top BIAB), I hope to clear out my beer. I’ve never done it before so I am looking forward to it. Thanks Matt for doing the work for us to view the results.
Also are you using a gas burner inside? ^_°
😉
Oh no. All electric system off a 220W plug with a 5500 low density wave heat source. I brew in Florida so going outside to stand by a fire is rarely an idea relished by the populous, so when I upgraded my kit, I stayed electric. Thanks for reading! Glad it helped.
I stopped recirculating many months ago. Clarity has never been an issue.
Thanks, nice experiment. I usually batch sparge and vorlauf but occasionally do a 1-gallon BIAB to test experimental recipes. The BIAB beers have severe chill haze, so your experiment makes complete sense to me. Although it might not matter for taste, it definitely seems to matter for clarity and I will continue doing it, probably all the more carefully now.
It’s interesting that fining didn’t clear the haze. You might get better results with other fining products.
…probably should have said more about the 2 oz of Saphir dry hop.
I don’t think I’ve ever dry hopped a lager – they look best crystal clear.
Well, if you can have a Pivo Pils, I recommend grabbing one. And you’d never know they were dealing with hop haze. I failed this time in my quest, but I shall return.
I use a cooler and braid but no bag. There’s some nice ‘soft’ reasons for doing the Vorlauf – it’s easy to see what it looks like and if it’s sugary, make sure the stream is going into the kettle instead of all over my shoes (whoops), taking an early gravity reading or ph, and it’s comforting dumping some wort back on top of the grain bed to loosen it up a bit and give it a rinse.
what temperature did you recirculate at? did you bring the temp up to mashout at 169?
I believe I posted the step mash schedule earlier (which we’ll try to get into the article, sorry for having the reference in the article but not in the recipe) in the comments, but I circulated while warming things up from the last mash stage to the mash out stage at 170F.
What impact could the hot recirculation have on the darker color?
Tyler – not sure what that could mean for the darker color or if that is a product of having less “flour” particulate involved involved.
the colors are different and i was wondering if you chalked this up to there being less particulate in the darker wort…therefore reflecting less light, etc…or if you thought maybe there was some low level maillard reaction taking place while you were recirculating at a high temperature?
Thanks for a great article. I’m always interested in BIAB experiments as this is the method I use.
Can I just ask if you squeeze your bag after draining? I squeeze the life out of mine as I’ve found it makes a difference to my efficiency. I fear a heavy squeeze would undo the work the vorlauf.
I do give it a solid squeeze, but nothing to heavy. Just enough to make sure I’ve gotten out the bulk of the wort. Thanks to my setup I can let it hang over the kettle while I bring the heat up so I can afford to be a bit patient. Happy to give you a BIAB perspective, we are seeing a lot of that.
As Simon pointed out, “squeezing” your sack can make a massive difference in the amount of flour that makes it into the kettle. The difference is visually noticeable while lifting your sack as the grain is distrubed. I BIAB and have noticed it while brewing. I’m working towards less squeezing and more lautering/vorlaufing, since it definitely results in clearer wort pre-boil. Adding a minimal volume dunk and drain will get you way past (efficiency wise) a single squeeze, and with less flour. Adding a vorlauf to both will put BIAB on equal footing with batch sparging (efficiency wise), while being somewhat simpler.
I still wonder what effect boiling has on that extra flour, even though I’ve implemented steps to remove as much trub post-boil as I deem possible.
Bo – it is a good squeeze, but I’m not trying to press it, just make sure I have not hit any hidden water/wort reserves. I appreciate your feedback, I think a BIAB dunk/no squeeze and a squeeze no sparge could be a good side by side xBmt if the team is not too tired of BIAB focused results. (Or just squeeze/no squeeze.)
I’m also liking the idea of big head space fermented vs. normal head space fermentation as mentioned above.
I fly sparge, but have used a Brew Bag as my mash tun screen since Marshall reviewed it and haven’t had to vorlauf since. Wort drains VERY clear from the start!
Great xBmt Matt. Keep up the good wort. I promise this is the one comment i will make. I won’t continue to take issue with every step of your process or every comment made. I think you may finally be attracting “Mr. Beer”. It was bound to happen.
My $0.02 worth from a non BIAB’er.
I vorlauf 3 to 5 times, at approximately 15 minutes a pop, drawing off 2 to 3 quarts for each one and stirring strongly between each re-circulation. What I’ve found is this; obviously I’m upsetting the grain bed but I have, over time, noticed a distinct pattern in grain sediment after all the wort has been transferred to my kettle. It seems that the vast majority of the husks tend to float back up to the surface and settle on top. Now, I do condition my grain and the husks, on average, have a “butterfly” look to them or, if you eat mussels, how the shells look after a boil. My final vorlauf has never been totally clear but, I can say with confidence, very few husks ever make it out of my mash tun. My efficiency is rarely below 80% and, when brewing in the summer, I can draw bees from two counties over.
After looking at the photos though, I think I might vorlauf through a bag and see what I catch.
Another well done Xbmt.
Thank you for everything you guys do.
Great experiment, as usual! I think you’re *slightly* underselling your results. A p-value of 0.063 indicates that if the two beers really were indistinguishable you would get the same number of or more participants accurately picking the odd one out only 6.3 times for every hundred trials…maybe not an acceptable finding for an academic journal but strong enough evidence for the average homebrewer (i.e. me) to think that vorlaufing might be a jolly good idea 🙂
They both look pretty dark for a 100% Pils malt brew. Why you think they came out so dark, HSA maybe?
My understanding is that HSA might impact color over a fairly long period of time, like months, and in my HSA xBmt, there was no noted color difference. I didn’t see the beers myself, but I’ve taken a bunch of pics of beer and noticed the lighting can make a Pale Ale look many different colors.
Also might have a lot to do with some hop addition color and the haze making it look a bit darker. One just to silver in German pils in a FL State competition. Haze was noted, but it dropped much clearer after a couple weeks in the keg.
Wait a minute — for the “vorlauf” batch, you vorlaufed to set the grain bed in a BIAB setup, then simply pulled the bag up out of the mash tun, leaving behind the wort? If true, that makes little sense, because you’ve completely wrecked the grain bed by disturbing the bag, thus making the vorlauf a waste of time. The wort will be cloudy with both batches. The proper test would be a standard BIAB mash (where you pull the bag out of the mash tun, thus leaving behind the wort) versus a mash where you vorlauf then runoff the wort from the bottom through an undisturbed filter bed, which will give you a very clear wort.
The objective was to see if there could be a difference detected between a BIAB with a vourlauf/circulation and without. It was not a “waste of time”, simply looking at the effects in that set up.
I’m curious to know if there was less trub in the vourlaufed batch’s fermenter. When I BIAB, it seems that I have a greater amount of trub. This is with siphoning off of as much kettle trub as possible.
Love the exBEERiments, and sorry about the old thread. I just started using a BIAB bag in my mash tun to speed clean up in a small NYC kitchen. But I find that no matter how much I recirculate, the wort is cloudy (no specs of grain, just the flour). The fine particulate matter is so powdery that is goes straight into the fermenter even if I am not too aggressive about draining the kettle. It’s nearly impossible to contain the trub and keep it out of the keg when transferring. (I’ve even had the post clog doing a closed transfer). How is it that you were able to clarify? I find that the bag causes the grain bed to float and not compact at all even after a lengthy vorlauf. Any ideas? Thanks!
If you’ve got too much float, try putting some tension on the grain bag to hold it in place while you mash. On my rig I just pull my bag up a bit on my pully I use when draining. Or, while I prefer a fine mash, you might need to open it up a bit if it’s too close to powder and getting out of your bag. I also saw a nice improvement when I went with The Brew Bag vs. the generic ones or a mesh bucket.
Do you use finings or secondary?