Lost Volume

[monk]

Another thread reminded me of a question I had, and since I didn't want to hijack someone else's...

When I did my last all-grain batch, I started the boil with a little over 6 gallons of wort. I ended up with only 3.5 in the fermenter. The 2.5 gallons were presumably lost to evaporation and mixed up with the break and hops in the fermenter. The leftover wort was 1060, so I brought it up to 4.5 gallons and still had a respectable gravity in the end.

My questions:
is this a normal amount of volume loss?

SHould I be just dumping the entire contents of the kettle into the fermenter and let the break and hops fall out in the primary?

Am I not sparging enough? (I followed the direction Papazian gives in JofHBing)

Thanks in advance,

monk

[mysterio]

Off the top of my head I would probably expect to lose half a gallon to hop absorption (I use a fair amount of hops) and maybe 1 - 1.5 gallons to evaporation. Obviously evaporation depends alot on how vigorous the boil is and if you have the lid partially on or completely off. So yeah, what you're saying doesnt seem too far off. I have lots of marks on my boiler at critical points like 5, 5.5 and 6 gallons. So i'll know I want to finish my boil around 5.5 and design/alter the recipe accordingly - I'll make my recipes for 5.5 gallons of wort, knowing i'll only get around 5 in the primary.

It's what you end up with in the fermenter which is the important part, though. If it's 1.060 in the primary and you intended to make a 1.050 beer, then you know topping it up with water will also dilute the bittering by the same factor as you're diluting the sugars, so there's no loss.

I wouldn't dump the break material and hops into the fermenter personally.

[Frothy]

Optimum boil reduction is ~ 10% and is apparently desirable as it affects the flavour extracted from the hops. Certainly allow for 20% in the recipe & with the big propane burner I've lost nearly as much as 30%

Frothy

[monk]

Thanks, guys. I'll read up on sparging a bit more. I think Papazian's instructions are only meant as a very cursory explanation and introduction. I think volume and temp control have been the only tricky parts of all-grain brewing for me, so far. The rest has gone pretty smoothly.

Luckily, on the last batch, I over hopped a bit. Otherwise when I diluted to get the right gravity/volume, I might've mellowed the bitterness too much.

Cheers, guys.

Alex

[SteveD]

Optimum boil reduction is ~ 10% and is apparently desirable as it affects the flavour extracted from the hops. Certainly allow for 20% in the recipe & with the big propane burner I've lost nearly as much as 30%

Frothy

Frothy, old boy.

Your propane burner, 8.5Kw. I need to get one that will happily boil about 70L give or take. (I've got a 100L pot for 50L brewlengths) Do you think yours will do it?

Boiling losses, last brew was 53L into the boiler, and 42L 90 minutes later, which is more than 10%, closer to 15% but then I've got 5.2KW of elektrickry elements doing the boiling (2 x 2.6kw Electrim elements)...40L into the Fermenters giving (2L - the volume of the hops) lost to the hops of which there were 205g initially. Volume brought back to 48L by rinsing the hops, and topping up.

[vaudy]

The propane burner that I use is approx 8.5 kW and copes with a 50 litre bringing it to the boil in a reasonable time whilst sparging.
I always boil my water prior to brewing topping the boiler up via a combi, about 50 litres @ 50 C during this process the boiler just about copes with bringing the liquor to the boil in a reasonable time, it would be slow if the water was cold to start with.
I would consider a more powerful burner if using it to boil from cold with the additional length that you intend (70 l), If like myself you boil water from warm, or don't bother with boiling prior to brewing I feel that you would be ok with a 8.5 kW burner.

Trust this will help.

Regards
Vaudy

[Frothy]

SteveD - I've heard of them being used sucessfully with 100L batches don't know how long it would take though. Vaudy your boilers 100L isn't it? & you use the same burner as me. I've not done a 50L boil yet (soon) but it boils nearly 30L in 20-30minutes. If it's one of those huge pots maybe you could just strap 2 or 3 of these burners together - of course in America some peeps use 2gazillion BTU burners & buy clean air from elsewhere see natural gas at the link below.

See "Burner Large"http://www.bes.ltd.uk/nav_graf/frames_cat.html

Frothy

[SteveD]

Putting two of those 8.8kw burners together might work out ok giving over 60,000 btu but at half the price of the single 60,000 btu burners in the natural gas section. Price looks reasonable too.

[PieOPah]

Obviously evaporation depends alot on how vigorous the boil is and if you have the lid partially on or completely off.

Shouldn't really have the lid on at all when boiling with the Hops in. I don't know if having the lid on partially will stop some of the 'nasty stuff' escaping, but I wouldn't want to take any chances....

I guess it would be okay to leave the lid on when bringing wort to the boil (before hops added), but even then I don't risk it!