Losses in brewing process

[Scooby]

The losses in the brewing process has always perplexed me, partly due I'm sure to poor calibration of vessels and not being able to see through insulation etc, so I paid particular attention to the calibration on the sight tube in my new HLT/Boiler.

I did the first brew with it yesterday and made notes throughout so I can fine tune the volumes in subsequent brews. I batch sparged and calculated 2 equal batches of 15.9l total wort collected 31.8l. Here are the volumes etc on the day.


Total wort collected 32l @ 1038 All OK
After 90min with 90g hops 26.3l @ 1047 12%/hr evap' as expected OK
Ran through Hop Back with 40g Hops, collected 18l @ 1042


So I lost over 8l to hop absorption, the dead space in the boiler (500ml) and HB (100ml) plus thermal expansion, 26.3l may be nearer 25.3l

I used to sparge the hops but stopped a long while ago so it was interesting to see that I lost 5 points from the sugars left in the hops.

I know the sight tube is accurate. The FV is marked in US gals, it was just below the 5 gal line and cornie is full from there, so that is accurate. The sg's also tied in with what I expected.

How does this compare with your losses, I know DaaB reckons on 3l to hops but collecting 37l to brew 23l seems excessive

[BarnsleyBrewer]

Hi,
Put a lid on your boiler like mine, loss is at a minimum!!

[Scooby]

That's a grand idea BB and has other advantages as well, you can pipe your lovely brewing smells right into your neighbours garden

I accept and planned for the loss due to evaporation, but didn't expect such a large loss to the hops.

[Aleman]

1Kg of Hops displaces 1L and absorbs 15L of wort
1Kg of spent hops retains 6L of wort

So I'm not sure if you agree with Greg or not . . . .

[Scooby]

1Kg of Hops displaces 1L and absorbs 15L of wort
1Kg of spent hops retains 6L of wort

So I'm not sure if you agree with Greg or not . . . .

Not sure but I have a confession to make, I was up at 5 to get the brew underway yesterday as I had other commitments later, I managed to clean out the tun and flush everything else except the boiler before I had to go so.....Today I poured all the wort from the boiler and HB and gently squeezed the hops, there was 1l of wort. the hops were moist but not dripping, I pressed them gently into 3 2l jugs.

The 1Kg retains 6l looks good, With 500ml dead space 500ml was retained by 130g hops. (They weren't squeezed dry).


1Kg of hops in packed block form sure look like thy would displace more than 1l


Which ever way you look at it I leave 7-8l in the boiler, so I would have needed to mash with 41.6l to collect 36.6l and have 30l after the boil

[Scooby]

With the latest crop of hops being pretty low in alpha acids, losses are going to be higher, especially if you are going for lots of late hops too. I've been aiming for a 30L preboil volume in my last few brews.

Yeh , but I had 32L pre boil, 26.3L post and only 18L in the FV

[Scooby]

What does your boiler drain down to without hops in ? You could be leaving an unnecessary amount of wort behind due to hop strainer design.

I tested it at 500ml. After squeezing the spent hops almost dry got 1L and enough hops to fill my jugs to 6L slightly compressed.

I'm off to check the dead space again now

[Totem]

Would squeesing the hops to get more wort out give a different result?

[Aleman]

Would squeesing the hops to get more wort out give a different result?

Yes but that would also release a lot of the break protein that we have taken the trouble to get stuck in there . . . leading to a inferior wort.

[Scooby]

Ok the dead space is a little more than 500ml at almost 1L, must have been thinking of the tun dead space

The 6L of spent hops is 90g in the boil and 40g in the hop back and ties in with the dead space to give 7l to hops and trub.

I'm happy to mash as I did but to leave 7l of water in the HLT after the second batch is in the tun, and add both batches to that to give me the required preboil volume as I prefer to boil 'all in' as opposed to topping up at the end. I will of course alter my efficiency to give the required OG

[Scooby]

I wonder if kettle shape makes any difference, how did dog food boiler compare ?

The same, but due to reasons I mentioned earlier I just thought it was due to high evaporation rate and adjusted accordingly. The DF boiler was more squat being wider and shallower, that is why I was supprised at the losses with the new one.

I'm confident the evaporation is 18% in 90min and that the loss is due to dead space, wort absorbed by the hops and the fact that 26L or so of wort at 100C cooled to 20C is only going to be 25L.

BTW I'd like to think you will keep expressing your views on here DaaB you old Shark

[Vossy1]

Scooby, beware the sight tube
They're great on the whole but every now and then you get a anomolous result.
If something funny is going on with your volumes it's quite likely the sight tube is blocked.
It's happened to me once before, but in reverse to your experience.
The wort volume kept dropping so I added liquor to compensate and at the end of the brew I was 4ltr over volume.

I blew through the st at the end of the brew, as I didn't believe what I was seeing and I was right. After 3 blows the level of the liquid rose 4 ltrs above target!

Just a word of warning

[Scooby]

Cheers Vossy thats a good tip