Welcome to the forum John :icon_cheers:
Your question is a great one and a very common one that I see very few good answers too.
When starting out in all-grain brewing, there are so many questions! The funny thing is that with BIAB,
many of them can be answered quickly and very well depending on your knowledge level.
Older brewers tend to forget just how bewildering and how fragmented internet information is on all-grain. It can be very hard for new brewers to get an answer to such a simple question as yours. Bribie has mentioned Brewmate and, of course, there is Beersmith which, in the next version, will have BIAB capabilities.
I spend quite a lot of time answering questions such as yours on
BIABrewer.info and I either already have a dialogue going with the above software providers or have made repeated attempts to. I am hoping this dialogue will give some great results soon.
In the meantime, I have found the best way to explain volumes, gravities and bitterness is via a simple spreadsheet. While a simple spreadsheet still begs many questions it is, at least, on a single computer screen so it allows you to follow the logic of the brewing process and easily talk a common language.
I will attach a few of these spreadsheets here (anyone can distribute these as long as they credit the original source and explain that the most up to date version can only be found on that site.)
The first is the basic version of what is known for now as
The Calculator. Studying this will hopefully answer your volumes question. Just take a bit of time to read each line - there is no quicker way I know of to get your next questions focussed.
View attachment 44445
I will also attach a copy of a 'The Calculator' spreadsheet that shows a great APA recipe that originated here on AHB! Read the recipe layout
here as well as it is a very good template for how recipes should be passed on.
View attachment 44446
One of the great things about the above spreadsheet is it gives you a great ball-park figure for working out evaporation rates as it is based on the surface area of your kettle which is the most significant factor in determining evaporation rates. I have offered this to both Beersmith and Brewmate and Brad from Beersmith has responded enthusiastically so maybe we will see this as a Beersmith tool soon?
A lot of people apologise when they write a long post on a forum. I'm not going to John. I've been around long enough now to
know that many brewing questions can't be answered in a few lines - it is hardly
ever possible to instantly impregnate information.
So, I reckon, download the above files, grab yourself a nice beer and allow yourself a good half hour or hour to study 'The Calculator' files. You will have more questions so jot them down. Many will disappear on your second relaxed beer. The ones that are left, I or others will be most happy to answer here.
Cheers,
Pat