Hop and Trub losses in the kettle and Dry Hop

[JoKing]

I realise that every ones brew systems are different, but there is one little tid bit of information that I haven't found available in any books that I've read, or online that I've found. Maybe I haven't tried hard enough to find it. Anyway, over the past few months, and after a couple of questions fellow brewers have asked me, I've been recording how much volume I've been losing due to break and hops in the kettle and losses due to dry hopping. I won’t go into great detail, but I've worked out some pretty general averages that other brewers can factor into their boil volume to help in calculating their packaging volume (finished beer). And me being into metric, and being OCD, I've rounded these figures to even numbers to make life easier.

Trub loss depends on many factors i.e. whether you use kettle finings, how much malt is in your recipe and the type of malt you use. So...

Each 5 kilos of malt in your grist yields 1 Liter of loss without kettle finings and 2 Liters of loss with kettle finings.

Each 100 grams of hops in your kettle yields 1 Liter of loss in the kettle.

Dry hopping is variable, but in my system each 100 grams yields 1 Liter of loss.

So, how can you use these figures to help you in your brew schedule? Simple - work backwards, and factor your system into it. Here we go...

Say you want 19 Liters of finished beer to go into your keg, and your recipe has 50grams of dry hop, and 120 grams in the kettle. And you are using 1 tsp Irish moss.

50 grams dry hop = +.5L
120 grams kettle hops = +1.2
Irish Moss break = +2L
Total post boil Volume needed is 19 + .5 + 1.2 + 2 = 22.7 Liters.

Now factor your boil loss into this, for me 1.5 hrs = 3.4 Liters of volume loss (15% total) = Boil Volume of 26.1 Liters. I have been collecting more lately for some unknown OCD reason but I think it stems from the idea that I can bottle off more beer once the process has been complete - even though I invariably suffer from yeast blowoff and volume losses because of that.

Anyway. I hope the information is found useful.

[Reviled]

Thats some damn usefull info mate, cheers :o) Now I need to mark some litre marks on my kettle!

[James P]

I marked my stirrer with notches every two litres, works a charm!

[jt]

I did that once too, created a weak point and eventually the stirrer snapped - right on the notch

[James P]

Jeepers JT, you should have stopped flogging yourself on brew day, unless you are Opus Die... :)

I'm going to have to watch that, as with my larger boils now the long handled tongs are about an inch sort of the bottle of the kettle when I need to recover my thermometer...

[JoKing]

I forgot to mention that this is with Pellets - not flowers.

But I do know that you lose even more volume when you use cones.

[Mike Neilson]

Yeah Very helpfull I have had these problems since I have increase malt, Hopping levels and Whirflock. For instance in the imperial pil on the weekend I ended up with 5l of Trub 350g hops and 6.5kgs of Malt, ADM Pils malt which I reacon you can increase loss to trub by .5. I ended with 19l after a 29L Boil @ 90mins.

[JoKing]

Thermal Expansion needs to be calculated too - from 100 degrees down to about 25, there expansion loss of about a liter... I think you could factor that into the calculations too.

[jt]

I factor 4% loss to post boil expansion loss - I originally wondered where that litre of wort had gone - don't think it doesn't happen !