A question on boil volumes

RobWalker · Jun 20, 2012

I've probably mentioned this before but so we're clear, my current method - 9L boil, chuck in extract and hops, "sparge" hop bag into cold water already in FV, mix boiled wort with cool water, pitch yeast. works a treat.

I recently realised how important accuracy is on this scale - turns out my beers were often considerably weaker than I calculated as I was using american gallons, so I'm getting my measurements down before brewing again.

I'm sorted, but what I want to know is, if I boil a total of 9L, include 1.5L in the boiloff, does the original 9L include the extract already thrown in? If that's the case, I just need to make up 9L of extract and water in the pot, easy enough. Or do I include it on top of the 9L?

Cheers.

jonnymorris · Jun 20, 2012

I'm not entirely clear on your question but, assuming you're talling extract brewing... I boil up 9-10 litres, ignore what-ever gets boiled off and just make it up to 23 litres when finished. Sound OK?

RobWalker · Jun 20, 2012

You miss out on your correct hop utilization, and with high alpha hops, that can make a big difference. That's about what I do, just trying to get the accuracy on! :)

jonnymorris · Jun 20, 2012

I read somewhere (can't remember where) that adjusting for hop utilisation wasn't a big deal. If only I could remember where it might add weight to this statement. :roll:

Edit: I was clearly talking b******s. Hop utilisation decreases with increasing SG. I stand corrected.

pittsy · Jun 20, 2012

its total volume , so extract then water to make a total of 9l but you also need to add amounts that evaporate , if you use this http://beercalculus.hopville.com/recipe , add in total amount liquid brewing but change amount boiled your IBU will drop so adjust amounts (hops) to get IBU as wanted (you prob know this though i just thought i'd post it for others etc ) :)