Hi there vanis and happy new year to you ,

Your post above is a good one as some of the answers that it requires are important ones that you'll only tend to find on this site.

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The first thing I am seeing is that you mention a three hour process. This makes me suspect that you only did a 60 minute mash and a 60 minute boil. These are not long enough. Here's some notes I have written on this in another thread...

A 90 Minute Mash - A 60 minute mash is not enough for a BIAB brew. In a traditional brew, at a minimum they will 60 minute mash and then they will spend at least another 30 minutes buggering around with sparging. This means that the grain is exposed to hot water for at least 90 minutes.

Time is very important when it comes to an efficient brewery. Remember with BIAB, the mash and sparge is combined. Cramming the mash/sparge into 60 minutes will give a lot different result to one done over 90 minutes. Go 90 minute and then a mash-out if you can.

A 90 Minute Boil - A 60 minute boil is certainly fine for an extract brew (the stuff has already been boiled) but it may not give you best quality on an all-grain brew. Many all-grainers do a 60 minute boil and their beers are fine if not perfect. You should be conscious though when you select a 60 minute boil that you are introducing risk factors. Read this.

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The next thing which is great to see is that you realise that sparging should only be done if your kettle cannot fit all your water into the mash. Even then though, it is only in the rarest of situations that you should consider sparging as the only water you can't fit into your kettle for the mash is equal to that retained by the grain which is equal, in litres, to about 0.6 of the volume of the grain in kilograms.

For example, if you are doing an average brew and using about 5 kilograms of grain, and your pot is small, if you fill y our mash up as much as practical, you will only gain 3 litres of space after you drain your bag. Sparging this 3 litres is of little gain. If you think on this, the only time when one should consider sparging is usually when two conditions occurr...

1. The kettle is too small to handle the 'Total Water Needed - TWN" for the brew AND...

2. The liquor to grain ratio in the mash is very large such as will occur if a very high gravity brew is being done.

So, while your set-up makes sparging less messy and awkward than it is for most set-ups, I am wondering why you are holding back as much as ten litres vanis? Maybe you can get away with a lot less?

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When asking about a true BIAB, the original intention and the real beauty of BIAB lies in it being a single vessel, single tier and single burner method. This was the reason why myself and others developed the method.

I would call you a true BIAB'er, in spirit, if you understood the above and I think you do. What happens though when people don't understand the above is that they bastardise BIAB. We find people sparging even when they have kettles big enough to do full volume mashing because they think sparging will increase their efficiency. Firstly, it doesn't and secondly they are actually three-vessel brewing but doing it very badly. In other words, they have lost sight of the purpose and elegance of BIAB.

So, if your kettle was large enough to full-volume mash but you didn't, I would be reluctant to call you a pure BIAB'er because you would have missed the point of what we have worked for over the last seven years.

If however, your kettle was on the small side and you understood the pros and cons of what we used to call 'maxi-BIAB' but now prefer to call 'Full Volume Variations - FVV' and that you do understand that a bigger kettle would make things easier for you, then I think you can certainly regard yourself as a pure BIAB'er in spirit.

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You refer to BIABacus maths above and efficiency. There is a lot of un-learning from other sites and re-learning you'll need to do here. BIAB is actually very efficient so the BIABacus does not make any compensations for this. If you do a search of this site of posts done by me, especially in threads of a few years ago, that contain the words, "unambiguous" "terminology" you will find some essays on how the lack of a consistent terminology around the world amongst home brewers has created many problems. Also try and find posts that describe the difference between kettle and fermentor efficiency as they are two different things.

Also read the, Does this recipe have integrity? thread. You'll see that there are very few reliable recipes on the net.

Regarding getting efficiency up to 100%, this is not possible for the brews we do. If you did a super light beer, then it would be possible to exceed 100% because you would be washing the grain with so much water. A 100% efficiency is also not desirable. A read of the Sweet Liquor Shop posts will explain why.

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You mention, "Given my method (a decent sparge) do I need to be upping the grain bill so muhc?"

What is happening here is you are filling out the wrong field in Section W. For example, try the following...

1. Blank out anything you have in Section W.
2. Look at the total weight of grain under 'What you will use...' in Section C.
3. Type 5 or 10 into 'Water Used in a Sparge' in Section W. The grain weight you will need will not change.
4. However, move that 5 or 10 to 'Water Added Before the Boil' and the amount of grain you will need rises.

The reason for the above is that in 4 above, you are exposing your grain to less water. It's a bit like washing your dishes in half a sink of water versus a full sink. A full sink will get your dishes cleaner.

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Finally, you mention about taking an OG reading. I'm pretty sure you know from what you have written that, in the context of kettle (and even, fermentor) efficiency, a gravity reading means nothing without an accompanying volume reading.

Putting this aside, if you had filled in 'Water Added Before the Boil' instead of 'Water Used in a Sparge' then you would have used more grain than needed and therefore ended up with more 'sugar' (volume x gravity) than intended but...

Another thing this site emphasises is that while it is at the cutting edge of numbers, it would also like every brewer to be aware that any actual number you record on a brew, especially gravity ones, are very open to error. This post on Number Respect and Disrespect will give more info.


PP

Hey there Vanis,

Can you post your file up here? That will make a few things easier to explain.

.

Sorry Vanis, I think we are going to need to go with your file from How to Brew.

In your file above, even if the 23 L above means 23 L 'Volume of Ambient Wort (VAW)', (the volume of wort at the end of the boil once cooled), if the original recipe only used 5100 grams, the kettle efficiency would need to be about 87%. There's something not right there*. It wouldn't be the first book with errors unfortunately.

Anyway, let's just go with the How to Brew recipe. This will make things a little easier.


PP

[*For Advanced Users Only: It's interesting to note that if the 23 L (6 gal) means VIF and there was 1 gallon of trub, the kettle efficiency would have to be 100%. I'm wondering if there is a major error in this book in the conversion from extract to all-grain?]

Out of interest does this book give you the recipe using extract, plus an AG option

vanislander wrote:Pistol, I already brewed the "how to brew" brown ale as per your instructions. I'm trying to get a 2nd brew going and I'm still wondering why the biabacus always tells me to add more grain than specified.

Okay, I've already spent several hours on this one thread so let's slow down a little and get this sorted.

I can't work on the recipe you have provided from the book. As mentioned in the last post, it is highly unlikely you will get 23 L of 1.057 wort from 5.1 kgs of grain and no book should be using such a high kettle efficiency figure. Also things like "23 L of beer at the end" can mean anything and I'll come back to this below.

I remember now that I did spend considerable time on your Nut Brown Ale but you need to remember that I do this with a lot of people so it is hard for me to remember individual details. Anyway, I have pulled up your file from the other thread.

Before I get onto the next bit, you'd be better off sticking to the 5 and 5 litres I had in Section W. Your kettle is too full otherwise at the beginning of the boil.

Why it 'appears' more grain is needed.

Hold on...

I was about to write the answer here but on checking in the other thread, I see the following...

1. I never recieved a reply to the detailed post I wrote to you here.

2. In that post and the one before it, I asked for a link to the original recipe as your grain amounts did not match the ones I could find in How to Brew.

3. In the original weights you provided in the Nut Brown Ale file, there is very little discrepancy between the grain weights and no discrepancy if you remove the 5 L of water added during the boil.

So, until I receive a recipe link and also a reply to that post I won't know why you think there is a discrepancy in the Nut Brown Ale file and I also won't really know if you have read the links I asked you to read in the other thread. Some of them are relevant.

...

So, it looks like I can't give a real life example but for anyone following this who wants to know why it may 'appear' that the BIABacus is asking you to use more grain than the original recipe, here is what is usually the case...

The critical volume figure needed in a recipe to copy it properly is the 'Volume of Ambient Wort (VAW)*'. This means the volume of wort at the end of the boil once it has cooled.

If someone gives me a recipe and says, "this will give you 23 L into your fermentor," it is impossible to copy accurately unless that brewer and I have exactly the same amount of kettle trub. For example, if I practice careful trub management, I will waste little between the kettle and fermentor so to get 23 L into the fementor, I might only need a brew with a Volume of Ambient Wort (VAW) of 25 L. However, the original brewer might practice no trub management and therefore waste a lot. His brew may have had to brew a VAW of 28 L to get the same volume into fermentor.

Obviously, it requires more grain to do a brew with a VAW of 28 L than it does one of 25 L.

So when comparing a recipe, you must compare the two VAW's and, with the way that most recipes are published, this is nearly always impossible or very difficult to do.

The BIABacus 'Kettle to Fermentor Loss (KFL)' default is set on the high side to allow a nice safety margin for the new brewer. This means you need more grain as you are brewing a higher VAW.

Finally, kettle efficiency also comes into play in this. However, the efficiency default the BIABacus uses will be higher than those used in most books and other software as the BIAB method is very efficient.

In summary though, all other things being the same, it will be a difference in VAW that results in a discrepancy in grain weights.

A great posting PP, thank you.

I need a brain transplant or a least another beer to understand it all but some it it is starting to get through.

Have just found your "How to add Honey..." Post and jumped straight to this one to better understand VAW's

Thank you, I find that some of the more esoteric posts have qualifying answers that help me understand some questions that are still unclear.

That's why I recommend a more general approach to members reading on the site. You never know what you might learn from the least likely threads.
Read em all even the older threads

Anyway I am waffling

Thanks again PP

Hey thanks for replying Yettiman . But, it was not your job to reply, it was vanislander's.

The funny thing Yetti, is that if you hadn't bumped the thread, I would have never noticed that vanis hadn't replied - lol. I write so much, I hardly ever get time to back-track. I think/hope most people reply (90-95%???, and most of them well) so why didn't vanis reply here? God knows how much time I spent on this thread . (Brewers who care too much . Faaaaarkkkkkk!)

A note to Vanislander

I see you logged in today and obviously would have read Yettiman's post. I did spend a lot of time on this thread but you never rep[lied to my last post. Can you let me know where I let you down? Even do it via PM if you want.


PP