Boiled for 75 minutes, whirlpooled and siphoned to cube for no chill. Small accident when the tap on the cube come loose, spilling boiling wort on the floor....got the tap back on within seconds and expelled all the air. I figure I should be ok?
My water in was 32 litres, ended with around 23 litres into the cube and left around 3 litres of trub and hop gunk in the kettle. Pre boil reading was 1040 and post was 1052, so I'm happy with that. How do you work out efficiency?
Swiss voil is as strong as hell!
Thats one of the reason "most" people who no-chill dont put a tap into their cube. Things go all a bit soggy at 100C and the taps tend to get knocked out really easily. Plus sanitation, people tend to be extra extra careful with no-chill and that tap is a prime place for bugs to hide.
If it were me, I'd retire the cube with the tap to a Cold Conditioning cube or to hold sanitiser or something, and go with cube that hasn't had the tap hole drilled out for no-chill.
Efficiency is usually measured as the gravity of the wort (for a given volume) expressed as a percentage of the maximum theoretical gravity you could have gotten in a perfect system.
There are calculations you can do - but the easiest way is to get yourself one of the brewing software programs. I use pro-mash and the free trial is fully functional, just with recipe saving disabled. It will still do all your calculations for you.
Plugging your grains and volumes into pro-mash...
you had 23 into your cube and 3 left in the kettle - that's a post boil volume of 26L
Your gravity was 1.052
2kg JW pale, 2kg JW pils, 1 kg corn
Promash says that to get 26L of 1.052 wort from those grains you would have had to get a mash efficiency of 86% -- which is great. So great in fact I suspect its a little high to be realistic.
But, lets assume a bit of measurement error - say 1L in the kettle and 1L in the cube. Thats 24L @ 1.052 which is still an efficiency of 79-80%.
So, either you measured well and got phenomenal efficiency, or you got a little error and just got really good efficiency instead. Nicely done.
A few more brews and you will start to settle into predictable patterns and you can think about aiming for particular numbers and designing your brews to get them. If thats how you want to brew anyway.
I have been talking about "Mash Efficiency" which is probably the most common way people think about efficiency. If you read a recipe in a brewing magazine, or you read a book like Brewing Classic Styles - then when they refer to efficiency, this is what they most probably mean.
Another way to look at it is total brewhouse efficiency - which includes your losses from the kettle to trub and things like that. It is a lower figure and might not look so good, but more accurately relates the amount of grain to the amount of beer. You can go a step further and include losses in your fermenter etc. So you relate the amount of grain directly to the amount of packaged product and a lot of people think that this is the only truly "useful" way to look at efficiency.
I use mash efficiency. Thats also the figure you are talking about when you use the efficiency button in the recipe design part of pro-mash... which is primarily why its the figure I choose to use.
TB