Lots of great posts above - some great advice on how if you are following all the basic rules and have accurate measuring equipment and still get low efficiency then pH is definitely the next cab off the rank. Also great comment from bcp on being careful not to lose the simplicity.
Just thought I'd try and help lespaul on the recipe conversion calcs...
Just using the calc spreadsheet for a couple of brews im planning this weekend (a kolsch and the irish red
http://www.aussiehomebrewer.com/forum//ind...&recipe=709)
with the grain bill it comes to 5.23kg but when i put it into the calculator with the opening gravity of 1.054 it tells me that it will be 6.2kg. Is this normal to be using an extra kilo for the BIAB method?
also when i am putting in the hop bill the recipe shows total bitterness and the aa% but when i put in the actual AA% that im using it gives me a much less IBU (22.7IBU with 43.8g at 45min and 27.2g at 15min). In the recipe i dont have the ammount of bittering of each hop addition but only the final. Is there a way to fix this?
Thanks
felten has nailed your problem on the grain bill side of things
. It gets very confusing working between different software programs and the way they can or need to be set up. Some brewers will use the term batch size as what goes into their fermenter while other brewer's, "recipe reports," mean the post-boil volume. It is often difficult to know which one they mean unless you know the software they are using and even knowing this sometimes means you still have to do some figuring or guessing to work out how they have set their software up!
And, it gets worse...
When converting recipes, every program will give you different gravity and bitterness results which is a PITA.
The Calculator* (or BIAB spreadsheet) uses a standard gravity formula but usually reads about 3 points different from Beersmith etc. The formula used for bitterness comes from John Palmer but reads far lower than other brewing software. For example, a recipe I plugged in the other day came up with...
ProMash = 41 IBU's
BeerSmith = 35 IBUs
Beer Alchemy = 43 IBUs
The Calculator = 31 IBUs
My goodness!!!
When communicating recipes, end of boil figures are the easiest to work. They are the common denominator of gravity and bitterness as these two things do not change from this point on. The best way of communicating recipes though is to take the time to explain the set-up your figures are based on such as Jamil and John do on Page 41 of, "Brewing Classic Styles," or in the manner of The Calculator where all volumes, gravities etc are described explicitly. This makes it easy for others.
What You Should Worry About/Do when Converting
The way I convert a recipe is...
1. Try to determine the original brewer's end of boil volume. (This can be difficult if the original brewer has used volume into fermenter as their batch size as you will have to guess at their losses after the boil or play around in the program
they used until you establish their post-boil volume.)
2. Now set your software or spreadsheet so as the end of boil volume matches the above.
3. Now set your efficiency figure to the original brewers efficiency figure (based on post-boil efficiency.)
3. Type into your software the original weights and times of ingredients.
4. Now take a note (write down) what OG and bitterness your software / spreadsheet reads.
5. Now type in
your desired end of boil volume (this will be what you want to get in your fermenter plus what you lose when transferring from the kettle/cube etc.) and
your efficiency figure.
6. Now adjust the grain weights until you "score" the OG you wrote down above. Often their is a scaling function on the software or spreadsheet that will do this for you.
7. Finally adjust your hops until you score the bitterness level you wrote down above. Once again most software or spreadsheets will do this for you.
Good recipes will take a lot of punishment so don't be panicked about making a stuff-up as you'll end up with a great beer anyway.
Jamil and John's recipes work on 75% efficiency and a post-boil volume of 22.7 L. The average end of boil efficiency on BIAB figures I have collected is a bit over 79%. I think a new brewer could happily copy any recipe in J & J's book exactly without worrying about the efficiency difference and end up with 19 L of splendid beer in their bottles or keg. It's a great book to have on your shelf.
So, if you were wondering why converting recipes can be a little bit demanding on your brain, hopefully the above shows why
.
Cheers,
Pat
* You are now free to distribute your recipes in The Calculator format providing you follow the copyright instruction explained
here. The name will also soon be changed to BIAB-Calculator to make it easier to find.