# Diluting your wort



## robbiep (29/1/13)

Hi guys,

I was wondering how it is possible to make 20litre batches with a 15 litlre stock pot?

Lets say a particular recipe has 4kgs of grain and I am able to put it in my stock pot with 10 litres of water.

After resting for 60mins, then I need to start boiling and adding in my hops. At this stage I might have about 9 litlres of liquid.

I have the following questions:

1: When I start boiling the hops, can I simply top up as much water as I can? i.e. try boil 12 litres in a 15 litlre stock pot

2: Does is matter if I boil with the lid on or not? Obviously more liquid is lost when boiling with lid off.

3: Once the hops has been boiled, lets say I am left with 10 litres of wort, can I simply add these 10 litres plus another 10 litres of cold
/ boiled water into fermenter?

Regards,
Robbie


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## nacnud (29/1/13)

Hi Robbie,

I'm also keen to know the answers to these questions. I did my first AG brew over the weekend and ended up with about 7L in my 15 litre pot after starting with 10. I ended up topping it up to 9L in the fermenter to bring the OG down a bit and increase volume. From what I've heard boiling with the lid on is a no-no as you need to let something boil off (I forget what it is) otherwise you get bad flavours?


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## manticle (29/1/13)

There are stovetop BIABers who can answer your dilution questions much better than I can. It is possible though. However working out desired gravity, volume and hop utilisation are the key factors.

Definitely leave the lid off for the boil - there's a whole lot of unwanted volatiles that get driven off during a boil - lid on works against that.


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## robbiep (29/1/13)

With regards to boiling with the lid on / off... i have been doing the in between... boiling with the lib on, but slightly off


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## bum (29/1/13)

That's fine until the boil is reached. Lid should be completely off during the entire boil.


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## carniebrew (29/1/13)

This is the eternal problem when moving from extract brewing to all grain/biab, but still doing partial boils. With extract brews, and I mean un-hopped extract here, not pre-hopped kit cans, you can add just enough extract to your partial boil to bring your "Boil Gravity" up to 1.040, which is the 'optimal' gravity for hop additions.

To break it down:
1. If steeping grains, add at least 3 times their weight in water to a pot, bring to around 70 degrees. Steep grains for 30 minutes, then remove grain.
2. Top up kettle to your pre-boil volume and start boiling
3. Once boiling, turn off heat. Add enough extract to your pot to bring your gravity up to 1040 (100 gm per litre for DME, 130gm for LME). Mix well.
4. Once mixed, return to heat and get boiling again
5. Once boiling, add your 60 minute hops and start your boil timer
6. As boil progresses, add your hop additions
7. With about 5 minutes to go in the boil, remove from heat and add the rest of your extract, mix well (some prefer to add this at flameout, up to you)
8. Return to heat and finish your boil.
9. Chill or no-chill....ferment as usual.

So, with BIAB and partial boil...how do you mash your grain but only have a boil gravity of 1.040? I guess you could mash in two stages/pots? Does anyone doing BIAB also do partial boils? The other option is to use two or three pots for the complete process in all?

And to answer your questions Robbie:


*1: When I start boiling the hops, can I simply top up as much water as I can? i.e. try boil 12 litres in a 15 litlre stock pot*
Yes, but you will have a very high "boil gravity", as you've got the full volume of grain in a partial volume of water. This can cause darkening of your beer, and can play havoc with your extraction of your hop acids (higher gravity boils mean less acids extracted from hops)

*2: Does is matter if I boil with the lid on or not? Obviously more liquid is lost when boiling with lid off.*
Don't boil with the lid on. It's bloody dangerous, you can almost guarantee a boil-over....and the boil is meant to remove DMS (cooked corn taste/flavour) from your wort. Bring your water to the boil with the lid on, but take it off just before/when it gets there.

*3: Once the hops has been boiled, lets say I am left with 10 litres of wort, can I simply add these 10 litres plus another 10 litres of cold/boiled water into fermenter?*
Yes, but you have the issue mentioned above of hops boiled in high gravity wort.

Some BIAB brewers can solve the problem by using only enough grain to bring their boil gravity to 1040 (say 2kg), then at the end of the boil they add malt extract to make up the rest of the grain bill before transferring to the fermenter and topping up with water.


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## bum (29/1/13)

carniebrew said:


> This is the eternal problem when moving from extract brewing to all grain/biab. With extract brews, and I mean un-hopped extract here, not pre-hopped kit cans, you can add just enough extract to your partial boil to bring your "Boil Gravity" up to 1.040, which is the 'optimal' gravity for hop additions.
> 
> To break it down:
> 1. If steeping grains, add at least 3 times their weight in water to a pot, bring to around 70 degrees. Steep grains for 30 minutes, then remove grain.
> ...


How does this help OP? He wants to brew over gravity then dilute, not under gravity then add fermentables.

Also, are you calculating your final IBU on the 1040 boil?


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## nacnud (29/1/13)

That was my thinking, Carnie. Just do it in two lots and mix together in the fermenter? Would be a full days work though!


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## carniebrew (29/1/13)

Aye...it takes me 3-4 hours for a full extract/specialty grain/60 minute partial boil as it is. If I had to do it 3 times...well...I just wouldn't. Hence the main reason I'm an extract brewer.


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## carniebrew (29/1/13)

bum said:


> How does this help OP? He wants to brew over gravity then dilute, not under gravity then add fermentables.
> 
> Also, are you calculating your final IBU on the 1040 boil?


Sorry Bum, had to write my post in a few goes due to computer issues. Please read again.

As for IBU calcs, the topic of much discussion within Ian's "Kit & Extract Beer Designer Spreadsheet" topic. We've pretty much agreed when doing 10 litre + boils that very little, if any, changes to hop additions is necessary. Less than 10 litre boils will likely need to up their hops accordingly. It's a matter of personal preference of course....personally I discovered this when doing an extract DSGA with a 10 litre boil....I used Ian's "hop concentration factor" and upped my hop additions...and ended up with a fabulous Amarillo-based IPA....my guess is it had 45-50 IBU's (based on some back to back tastings I did with some IPA's from Dan's); So nothing like what the DSGA was meant to have.


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## bum (29/1/13)

Boiling hops at over 1040 is not an issue at all. I'm not sure why carniebrew suggest otherwise. You just need more hops. 1040 is a theoretical "ideal". I'd be really surprised if there were more than a tiny handful of people (or ANY commercial brewies) building big beers at 1040 then adding fermentables late/post boil. Boiling hops at very high gravities will not ruin a beer - you just need more of them. Flip-side of the coin is that boiling hops at _very_ low gravities can lead to some fairly nasty flavours.

[EDIT: typos]


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## Amber Fluid (29/1/13)

I am just about to knock off work so can't elaborate at the moment... check out http://www.biabrewer.info/viewtopic.php?f=89&t=615

Do a search for MaxiBIAB


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## carniebrew (29/1/13)

Certainly didn't say it'd "ruin a beer", or that you can't boil over 1040. Be fair here....I just said you'd need to "adjust hop additions accordingly".

I don't understand your example of AG brewers/commercial breweries....they're not doing partial boils, so wouldn't need to add any fermentables post boil. It's the combination of small boil volumes and high wort gravities that can change your beer profile.


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## stux (29/1/13)

robbiep said:


> Hi guys,
> 
> I was wondering how it is possible to make 20litre batches with a 15 litlre stock pot?
> 
> ...


The big limiting factor is grain absorption. The more grain you have in a limited space, they higher the gravity, which means the lautering loss will be more and more significant.

Eventually your losses reach about 50% and then more grain results in less beer. That's the limit.

So, you can brew overgravity, you can compensate for the overgravity affecting hop usage by using more hops... which results in more trub and more wastage... and then you can dilute in the fermenter.

Look up Max-biab

I made up a clever calcualtor which can be used to work out how much grain and what water volumes to use with a given pot size to get a given amount of beer at a certain og.

works pretty well.

A New Approach to BIAB Calculus using Conversion Efficiency


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## bum (29/1/13)

carniebrew said:


> I don't understand your example of AG brewers/commercial breweries....they're not doing partial boils,


Neither is OP. What the ungodly **** are you talking about.


carniebrew said:


> so wouldn't need to add any fermentables post boil.


Even if they were, they wouldn't because it is stupid, harder and unpredictable/less repeatable. They'd boil the beer they want to make (feeding big beers like trappist style beers/etc aside).


carniebrew said:


> It's the combination of small boil volumes and high wort gravities that can change your beer profile.


Everything you do can change your beer profile (whatever you think that is). There's no reason at all to be telling him to do a 1040 boil then add fermentables like you are - especially when it is the _exact opposite_ of what he's asking about.

Your advice is awful. Make your beer the way you want to. Stop advising people on how to do things you've never done/don't understand.


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## carniebrew (29/1/13)

Huh? Jesus you're an angry bastard. How is the OP not doing partial boils? He's got a 15l pot and wants to make 20l batches. That's exactly the reason people do extract brewing, with the late extract addition method. This method is huge in the USA, where there are a lot more extract brewers. Adding fermentables post boil (late extract addition) is a process followed widely in extract home brewing, and has been for many years. Just because you don't understand it (and I dare say have never tried it) doesn't make it stupid. Any chance you could follow your own advice here?

I do partial boils for full volume brews. Stop bashing blokes who are just trying to help/join in the discussion. I never TOLD him to do a 1040 boil then add fermentables...I mentioned this is what extract brewers do...and if there's a way to do something similar with BIAB then the same rules would apply.


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## bradsbrew (29/1/13)

robbiep said:


> Hi guys,
> 
> I was wondering how it is possible to make 20litre batches with a 15 litlre stock pot? Yes you can.
> 
> ...


Answer to your question is yes you can dilute your wort. But really you should try to get your self a bigger pot. Also how are you separating the grain from the wort? You are going to get terrible efficiency unless you can sparge.
I have tried to answer your questions but do not recomend this technique. Look up Nickjd's $30 thread it will help you heaps. 

http://aussiehomebrewer.com/topic/44264-20l-stovetop-all-grain-aussie-lager/?hl=%20nickjd


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## bum (29/1/13)

carniebrew said:


> I never TOLD him to do a 1040 boil then add fermentables...I mentioned this is what extract brewers do.


This is what all extract brewers do? No. Definitely not as common in the States as you mention. They go full volume more often than not.

As for everything else you've said, read the thread - everyone else seems to get that OP is asking about brewing over gravity then diluting. Again (for the third time, I think), the exact opposite of what you keep talking about.


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## fletcher (29/1/13)

not an answer to your question but if all else fails nacnud, just make a few mini batches (of different styles or similar) and do experiments to see which things you like. i have a small pot and make heaps of smaller 10L batches (about 15-17 longnecks) and for me, that's a great amount for experimentation.

one thing i've had fun with is using the same grain bill, but changing up hop styles and times for adding them, or using different yeasts, or different mash temperatures etc.

apologies that i haven't answered your question but it's a really fun and educational work-around if you can't get a larger pot (like me!).

happy brewing!


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## stakka82 (29/1/13)

As mentioned above, there's a limit to how much grain you can use in a small pot before your efficiency starts going backwards.

I use a big w 19l pot, and sparge in a 15l pot, and i get between 80 and 85% efficiency with grain bills up to 3.2-3.4 kgs. After that I find I go backwards pretty quickly, plus such a big bag of wet grain is a pain in the ass to sqeeze over a small pot and not spill shit everywhere.

As also mentioned above, you really need to check out Nick JD's all grain for 30 bucks thread. He talks about a lot of the things youre asking about.

And yeah, lid off for the whole boil.


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## RdeVjun (30/1/13)

In answer to the OP, it is indeed possible to make *All- Grain* batches beyond kettle volume and if you're across standard BIAB methods in what ever kettle you have then the method is not really that hard, all that's needed as far as extra equipment goes is a simple bucket for sparging. Nick JD's 20L Stovetop thread is one method, there's also the MaxiBIAB guide on BIABrewer which is in much the same vein.
23L of 1.050 in the fermenter out of a 19L big double ewe kettle is routine, it seems to scale fairly well so a 15L kettle should yield about 18L. The process is volume- limited, so when mashing the kettle must be full, when the boil starts it must be full as well, sparging the mash is utilised to make up additional kettle volume which is lost to grain removal but also earns valuable specific gravity points. Dilution is in the fermenter, this lends some neat features, the process gives you the exact OG at the expense of variable volume, but is dependant on efficiency. I know lots of brewers tear their hair out over missed targets, this method dispenses with most of that pain if the brewer is prepared to accept a few litres either way.
OP's Q1. Not really sure what the question is here. However, when adding any water to a MaxiBIAB before wort hits the fermenter, make sure it does something useful for you (i.e. as either mash or sparge), so don't add plain water to the boil, only to the fermenter as post- boil dilution. Use any water to recover more sugars is my suggestion.
Q2. Certainly don't leave the lid on completely for the boil, however you may be able to rest it partially on the kettle. Want the supposed nasty volatiles to escape during the boil, that won't happen if it is totally enclosed by the lid.
Q3. Yes you can, provided the wort is sufficiently concentrated. There's no free rides with all- grain brewing, it requires a certain mass of dissolved sugars (+ some other fun stuff which makes beer interesting) to reach a particular specific gravity; quite simply if you've mashed a sufficient amount of grain appropriately and extracted the sugars efficiently then it can be diluted to the desired OG. Hops utilisation efficiency does become an issue as far as bittering goes for boiling of wort above 1.050, however in my experience it really isn't worth getting too excited about (seems to be about 10% per 1.010 above 1.050, not really a major drama even with concentrated MaxiBIAB wort).

FWIW, once I'd tailored a recipe to my liking, in a 19 stovetop setting the multiple mashes and boils of the stock BIAB method to get a fermenter full seemed very inefficient to me. That's the challenge that inspired development of MaxiBIAB, I was wanting a full standard fermenter and doing two MiniBIABs in the 19L kettle- my FSM, it was a long, long day and I would've given that up a long time ago were it not for some lateral thinking.

As noted by Stux and stakka82, there is indeed a point of diminishing return with MaxiBIAB, however I've not had that much trouble with >5kg of grain in the 19L kettle, although that's probably approaching the upper limit for practical implementation for your standard/ everyday beer.

And before anyone gets too excited, the very same MaxiBIAB method earned a 1st at AABC last year, so evidently there's no quality issues with it. That's actually tribute to all the hard slog of experimentation and development (ahem- brewing yet more beer?! ), but also the effort and dedication of fellow brewers advancing the technique. :icon_cheers:


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## stux (30/1/13)

Interesting thing with max-BIAB is the liquor to grain ratio is more like that or a traditional 3V mash and then the sparge, means it probably produces worts more like a 3V wort than standard BIAB


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## RdeVjun (30/1/13)

Stux said:


> Interesting thing with max-BIAB is the liquor to grain ratio is more like that or a traditional 3V mash and then the sparge, means it probably produces worts more like a 3V wort than standard BIAB


Yep, an interesting coincedence, but not by design. Whether that makes any tangible difference I'm not willing to speculate, but the method sure does knock out some superb beers. B)


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## Nick JD (30/1/13)

Anyone who's struggling to grasp the concept of high-gravity brewing needs to either get a bigger kettle or a bigger brain.


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## RdeVjun (30/1/13)

Nick JD said:


> Anyone who's struggling to grasp the concept of high-gravity brewing needs to either get a bigger kettle or a bigger brain.


Pay that! :lol:


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