A Guide To All-grain Brewing In A Bag

[MarkBastard]

Squeezing - jeez... how much are you guys trying to squeeze that its such a pain?? Pull the bag out... let it hang over a bucket till it stops dripping, give it a quick squeeze for a few seconds.... done. If the entire process of pulling and squeezing your bag takes a cumulative total even of 2mins worth of you actually doing something (not including dripping time) you're working too hard.

All I was suggesting was that instead of 'hanging' over a bucket, I want to put in a cake rack into the bucket that will act as a spacer between the grain bag and the bottom of the bucket.

This would be a zero squeeze solution.

I can't talk for everyone's grain bag, but mine drains pretty damn slowly. When I first pull it out there's actually liquid above the grain that does NOT just fall out of the size of the bag straight away. The bag is actually temporary able to hold an amount of liquid and impede that liquids flow. This causes almost a suction when pulling the bag out. Then once I have it above the level of the wort, the water does take a while to drain out of the bag. I don't mean a while to fully drain, but a while to sensibly drain. You need to hold it above the urn/kettle for at least a few minutes until the constant stream stops flowing so heavily.

My idea is to be able to transfer it to sitting on the cake rack in the bucket as quickly as possible, so you don't have to sit there holding the bag for as long. This would make the most 'stressful' part of the BIAB process much easier. The bag would then fully drain into the bottom of the bucket without a skyhook or rope around a door (that will then get sticky crap all over it). You can then add that runoff all in one go to the main pot. Piss easy. Easier than anything that involves a rope.

There's no extra equipment. You're replacing a rope plus either a skyhook or door handle with a cheap cake rack which can no doubt be used by SWMBO in the kitchen anyway.

 

[Thirsty Boy]

Well that make a lot of sense - in your instance its because you have a different material than the normal one, which makes your bag behave differently. So you get a different experience. The normal "voile" recommended for BIAB does drain the majority of free liquid almost immediately - with liquid draining from the grain being the rate limiting step.

At any rate - I wasn't actually questioning your cake rack idea - perfectly fine idea imho - cake rack/colander/bit of mesh over a bucket... same job as hanging.

I was only questioning that I have heard a few people mention what a chore squeezing was... and wondered why, what they were doing differently, when its so easy for me.

 

[Phoney]

Not quite true, a fly or double run-off batch sparge on a traditional mash will give you better efficiency than a full volume BIAB flood sparge - but again it's not essential to making good beer.

But then, I almost always hit 75% efficiency with my full volume BIAB flood sparges, so I wouldnt really want much better efficiency than that.... would I?

(This might change when the Urninator comes online but we shall wait and see)

I actually concur entirely with Ross - I see so many people starting to creep up the complexity of their BIAB systems and also think that they might well benefit from a serious consideration of the non-BIAB options.

Certainly not everyone - some people want to fancy up their BIAB systems and intend to deliberately stick with BIAB because they like it the fundamentals. But others started BIABing solely for the simplicity... if they are going to fancy up. There is a whole world of other options out there, some of which I think are a bit better than BIAB at various aspects of the brewing process.

Yes as Ross also pointed out, one of the two main benefits of BIAB is minimal equipment. Equipment takes up space, especially 50L+ vessels. If you are severely limited in living space, like me; I opted for BIAB over traditional setups because I simply dont have enough room for a 3V HERMS setup in my home. So all I can do is fancy up what I have to work with to make my brew day all the more easier, effortless, efficient and consistent. This is what I have been trying to do so far and what I intend to keep on doing. Reducing a 2 minute procedure down to a 20 second procedure is at least worth researching and experimenting in as it all ads up! (in my opinion anyway)

Now that it's been confirmed that squeezing that extra 1/2L of sweet wort out of the grains isnt actually worth any effort im happy to move on.

 

[katzke]

Now that it's been confirmed that squeezing that extra 1/2L of sweet wort out of the grains isnt actually worth any effort im happy to move on.

One thing you can do with the hour or more you have while boiling is mess about with the bag of grain and see if you can get any extra wort from it with minimal effort. It could be that you are leaving wort behind that could be easily recovered.

Course if you get an extra liter or 2 then you have to mess about with your water volume to get your recipe to work out.

Sometimes it is best to leave well enough alone.

 

[katzke]

Katzke,

No baiting intended... i was simply stating that if you are going to use additional vessels to drop your bag into & don't like lifting/hanging/dripping, why not mash in the traditional manner. The whole concept of BIAB is supposed to simplicity & using minimum equipment.

Ross,

Sorry bait may not have been the best word.

The best part of BIAB is the simplicity of it. I think it is easier then when I was brewing with steeping grains and liquid extract. That could be why some of us defend the simple version. I was sure that was what you were saying. Just wanted to remove any doubt.

Brewing on a 2 or 3 vessel system is much more involved. I never hear anyone complaining about brewers that add complicated contraptions to multi vessel systems. I know of one that can only be used by the designer as it has so many valves that no other human can figure out how to brew with it.

 

[felten]

When I first pull it out there's actually liquid above the grain that does NOT just fall out of the size of the bag straight away. The bag is actually temporary able to hold an amount of liquid and impede that liquids flow. This causes almost a suction when pulling the bag out. Then once I have it above the level of the wort, the water does take a while to drain out of the bag. I don't mean a while to fully drain, but a while to sensibly drain. You need to hold it above the urn/kettle for at least a few minutes until the constant stream stops flowing so heavily.

I have the same kind of material and it's definitely a major pain in the arse to lift out, I have a hook above my brew pot that helps out, and lets me tie it up, but it really could do with a pulley setup.

As for squeezing, I choked the crap out of mine for a while :X good to know It doesn't have to be done in the future.

 

[malbur]

It took me a while to workout why I was going through so many bags, the bags where all pulled around the stitching after only 5 brews, and it all came down to squeezing the hell out of it, so now I am a little bit gentler with squeezing and twisting of the bag with still the same results :icon_cheers:

Mal

 

[Lord Raja Goomba I]

I have a pasta pot of 9L, with a metal pasta strainer in it.

After my first BIAB, and what appeared to be poor efficiency (or just a crappy hyrdrometer) and my hands were a little red afterward (fortunately my kids weigh about the same as a wet bag of grain, so I could hold it up) and stuff going everywhere (and the associated complaints from the allegedly better half) - I thought "I'll just dump the grain in the pasta top one, and run a little hot water over it, squeeze it and get soem stuff out of it".

I know I'm probably opening another "simplicity" can of worms, but it appears to be the middle ground between efficiency and simplicity - it appears to be better than hanging, dunking, twisting and so forth.

 

[Thirsty Boy]

It was your first BIAB.... I suggest that any conclusions you drew about the method's possible efficiency or mess making potential were perhaps premature??

The point is - that with normal, no sparge BIAB - you should be getting efficiencies in the 70-80% range.. if you aren't, then you are doing something else wrong - it is not that you need to sparge.

You can sparge - but you should not need to sparge to be getting efficiency of the same order as a batch sparge system. No one is saying not to sparge - no one!! Just that you don't need to to brew in a effective and efficient manner.

 

[Lord Raja Goomba I]

It was your first BIAB.... I suggest that any conclusions you drew about the method's possible efficiency or mess making potential were perhaps premature??

The point is - that with normal, no sparge BIAB - you should be getting efficiencies in the 70-80% range.. if you aren't, then you are doing something else wrong - it is not that you need to sparge.

You can sparge - but you should not need to sparge to be getting efficiency of the same order as a batch sparge system. No one is saying not to sparge - no one!! Just that you don't need to to brew in a effective and efficient manner.

I probably should clarify that I didn't sparge, just squeezed the bag. Just thought next time I'd sparge (well at least find a better way to squeeze, hence the pasta pot).

Part of it (I know of) was the fact that I used too small a pot for the size of the wort I needed and so watered it down. Having said that, years of partial extract brewing told me that the taste of the wort was reasonable, if slightly weakened. Bitterness where I'd wanted it.

Lesson to me was to stick to 9L batches until I can obtain a pot big enough to mash in or use two pots and do 2 concurrent mashes, boil and combine. Not sure about that, and besides, I like being able to experiment often.

 

[MarkBastard]

with normal, no sparge BIAB - you should be getting efficiencies in the 70-80% range.. if you aren't, then you are doing something else wrong

Is that into fermenter efficiency?

 

[PistolPatch]

Is that into fermenter efficiency?

That would be mash efficiency* that is being referred to Mark. Efficiency into fermenter is usually a lot lower for all types of AG brewing. Efficiency talk can get very confusing especially when some posts are made based on guesses rather than personal experience and science. A bit of this has been going on here recently so...

BIAB Efficiency (Non-Fiction )​

BIAB is actually a very efficient brewing method - about 4.5% higher than batch-sparging done with a double run-off. This is not based on guesses but on personal experience and fact...

1. Personal Experience - Using the same kettle (and this is important) I achieved brews about 4%-5% higher than batch-sparging with a double run-off. Same recipes etc and based on several brews.

2. Science - If you want to wade through this article, you will find that Briggs, a well-known brewing authority, concludes, "that thinner mashes perform better and allow for better extraction of the grain."

It is important to listen to sources that have done the experiments and/or collected the figures. When comparing one batch to another it is also important to ensure the same size kettle is being used. (Larger kettles require more water due to higher evaporation and therefore will yield slightly higher efficiencies.) The figures I have collected from myself and other brewers show an average mash efficiency of 79.25% which is great.

This no miracle. There are several simple reasons why a BIAB brew (raised to mash out temperatures) will give higher efficiency than a double run-off batch-sparge.

A. No "Tun" Deadspace: In BIAB there is no deadspace.

B. Higher Sparge Temperature: In a double run-off batch sparge, it is impossible to get the grain bed to mash out temperatures on the first run-off even when adding boiling water straight to the bed (which isn't a truly great idea anyway.) If adding water at say 78 degrees you will, of course, never be able to get the grain bed to mash out temperature. In BIAB, the entire sparge can be done at mash out temperature. In other words, with BIAB we are able to do a much higher temperature sparge. This is a great advantage.

C. Larger Surface Area Run-Off: With traditional brewing, the run-off from the sparge is confined to the mash tun outlet. Besides possible channelling problems, the sparge is also slow. With BIAB, there is no channelling and the run-off is fast as the wort can escape through the entire surface area of the wetted grain bag. You can drain a mash tun or a bag for several hours and get run-off if you want to. This of course is silly. If however you decide on cutting your sparge at the start of the boil, then you will have drained more liquor from the bag than you will have from the tun. This is the reason why a BIAB grain bed weighs less than a traditional bed.

I hope the above establishes that BIAB is a very efficient mash - just one of its many advantages.

Spot ya,
Pat

*Mash efficiency is either efficiency into boiler or post-boil efficiency. Theoretically these two figures should be identical. The brewer's figures I have collected show an average discrepancy of 2.5% between these figures - nothing to get hung up on though. The figure of 79.25% used above is the average of the two.

 

[Ross]

BIAB is actually a very efficient brewing method - about 4.5% higher than batch-sparging done with a double run-off. This is not based on guesses but on personal experience and fact...

Sorry Pat, but i don't believe this statement is not correct. Efficiency with a single dunk sparge cannont give better efficiency than a double run-off batch sparge, all things being equal.
I brew both both ways with my current RIMS unit, & the single full volume mash consistantly gives over 10% lower efficiency.

Think about it..... If the full volume wort is at 1050, in a single run-off, the wort left in the grain after draining is at 1050.
If you do a double equal run-off, the first runnings will say be at 1070 & on your second run-off at 1030 (approx theoretical figures, as I don't have my notes in front of me) - therefore the wort remaining in the grain is at 1030
This equals greater efficiency into your kettle.

If you have an explanation to why you believe it's the other way around I'd be keen to hear it.

Cheers Ross

 

[MarkBastard]

Is there any chance the wort in the grain is actually at a higher SG than the wort that surrounded it?

I've always thought it'd make sense if the wort sticking to the grain or soaked into the grain would have a higher sugar content if anything, even if not by much.

So in a BIAB at 1.050 the wort you squeeze out of the bag may be 1.060 SG.

Someone with a refractometer want to test this?

 

[Ross]

Is there any chance the wort in the grain is actually at a higher SG than the wort that surrounded it?

I've always thought it'd make sense if the wort sticking to the grain or soaked into the grain would have a higher sugar content if anything, even if not by much.

So in a BIAB at 1.050 the wort you squeeze out of the bag may be 1.060 SG.

Someone with a refractometer want to test this?

Mark,

that's one of the main reasons for lifting the temp for a mash out. a well stirred mash at 78c will be pretty consistant - Don't forget, someone batch sparging can press their grain bed just as easily as squeezing a bag (if not easier), so as I said, all things being equal, a double run-off should always give better efficiency.

Again though, don't get hung up on efficiency, BIAB is about simplicity, if you want maximum extraction you'll need to fly sparge or squeeze every last drop of wort from your grain.

Cheers Ross

 

[PistolPatch]

Howdy Ross . My figures actually don't even include a dunk sparge - it is simply a full-volume mash raised to mash out temperature and the bag drained until the boil starts.

I thought my explanations were pretty clear above and the link I gave to the science is well-written. Sorry if I have missed something but I can't write any clearer or in more detail than I have.

I'm not too sure of your 1.070 versus 1.030 thing. If I drain 2/3rds of my wort at 1030 and only a 1/3 at 1070 my average is going to be closer to 1.030 than 1.070 right? Also a run-off of 1.030 does not necessarily mean the entire bed is at 1.030. These things are never even.

What would be great would be if more figures were contributed on all this stuff. We had some figures rolling in on BIAB for a while which was great. I have never seen a collection of traditional figures which is a shame. More figures would be nice. At the moment we can only rely on the few people who have done both BIAB and traditional brewing as well as good old Briggs .

Spot!
Pat

 

[Thirsty Boy]

Sorry Pat, but i don't believe this statement is not correct. Efficiency with a single dunk sparge cannont give better efficiency than a double run-off batch sparge, all things being equal.
I brew both both ways with my current RIMS unit, & the single full volume mash consistantly gives over 10% lower efficiency.

Think about it..... If the full volume wort is at 1050, in a single run-off, the wort left in the grain after draining is at 1050.
If you do a double equal run-off, the first runnings will say be at 1070 & on your second run-off at 1030 (approx theoretical figures, as I don't have my notes in front of me) - therefore the wort remaining in the grain is at 1030
This equals greater efficiency into your kettle.

If you have an explanation to why you believe it's the other way around I'd be keen to hear it.

Cheers Ross

Its mainly about deadspace Ross - and about the amount of liquor lost to the spent grain. If you leave 1L/kg behind in a mash tun - then by leaving only 0.5L/kg behind in a bag - the wort trapped can be anywhere up to twice as strong before you break even. And thats what it does... pretty much break even. And then where BIAB might nudge ahead... is with any deadspace in your tun.

I did some experiments on gravity left behind in my mash tun vs gravity left behind in a BIAB bag and it turned out that with a 2 run-off batch sparge, the gravity of the wort "lost" was about 0.333 x the gravity of the wort in the kettle. The gravity trapped in a BIAB bag is of course equal to that of the wort in the kettle.

So which is better depends on a combination of your deadspace and your actual kettle gravity. I translated that to KG of grain used, plugged in the numbers and came up with a graph. This is the theoretical minimum % of the sugars you create, that you must lose to spent grain and deadspace. BIAB wins for a little while.. then it loses as the size of your grist goes up.

This doesn't take into account the other things that Pat mentioned (L:G ratio, sparging temp and raising to a mashout) - which I think are true to enough of an extent to make a noticeable difference. In my experience, BIAB efficiencies aren't really better than batch efficiencies, a little perhaps at lower gravities - but they also aren't worse until your anticipated OG starts to get fairly high.

Anyway - here's the graph.

View attachment BIAB_vs_Batch._Sugar_extracton.xls

 

[boobiedazzler]

Well that make a lot of sense - in your instance its because you have a different material than the normal one, which makes your bag behave differently. So you get a different experience. The normal voile recommended for BIAB does drain the majority of free liquid almost immediately - with liquid draining from the grain being the rate limiting step.

What is 'normal' ? I have purchased two lots of poly voile from spotlight, ages ago for my partials and now for the full grain bill. They both behaved in the same manner, in that it would drain a lot after hanging, but there is at least another litre of wort to be pulled with a moderate squeeze. I have also seen a commercial bag that had a looser weave than the spotlight material, but not draining. I personally dont think that the difference in voile material is the culprit in holding back the juices. Wet, pourous cereal is the culprit ! How many parts of a micron is hot liquidified sugar ?

I am with Mark in thinking that the squuezed out wort is probably a higher OG. Though trying to apply any scientific reasoning to it is not within my tipsy capability right now I will borrow a refractometer next time and see what the outcome is.

 

[Thirsty Boy]

well - to be brutally honest about it - normal is when it behaves in the way that the guide says it will behave. If it doesn't, then its not normal and you have potentially bought the wrong stuff.

The "standing liquid" should drain almost immediately, this may well depend on the material you choose. The remaining liquid will drain over a period of time and as you suggest, the rate at which it does will depend in the composition of the grist. No one is debating that a squeeze will yield more liquid than not squeezing.. it will, no matter what liquid you choose.

Mark described a situation in which his bag was retaining the free or standing liquid - that's not normal.

Here's how it works on my BIAB rig and worked on the other 3 BIAB systems I have brewed on or seen being brewed on.

The vast majority of free liquid should fall instantly out of the bag and the rest should be gone in seconds. Then over the next 10 or 15 minutes the rest of the liquid will drain out of the trapped grain... after its down to an occasional drip, you give it a light squeeze and that'll give you 0.5-1L of extra

As Ross said - if you have stirred your brew the way you should.. then the gravity of teh wort coming out of the grain will not be noticably different to the gravity of the main liquid - if things are too hot, or your pH is too high, then perhaps squeezing too hard might extract excessive tannins and that would give a little increase.. so if the gravity is any higher in your squeezed liquor.. I would be concerned and not squeeze anymore.

 

[boobiedazzler]

What guide?

There isnt an MSDS available on Spotlight's Swiss Voile.

BIAB tutorials are only written with any given author's experience in mind.

For the record, that old PLU for the product that was floating around - Spotlight have changed their codes, according to the girl at my local outlet. Not to be found on their database.

I know you dont see much in the the sparging addition, but conversly Im sure you have elsewhere advocated adding extra water to the boil. So I have taken both elements and decided to use post-sparge water filtered through drained/squeezed grain, and will continue to refine the tecnique, thinking of an old shower rose hanging inside the drawn up bag, and a funnel in which hot water can be poured. The resulting liqor will be the added water.

Of course this is getting away from the keep-it-simple-stupid beauty of BIAB, but to the naysayers I say why not complicate it a bit, there's plenty of downtime between steps if the brewer wants to keep things brew-related. If it only contributes an extra point of gravity, its still more efficient use of the potential yields.