Losses In The Kettle

[Mercs Own]

3rd AG complete yesterday - having fun and getting more understanding about what I am doing.

I am interested to know what kind of losses people are getting in the kettle etc I had a total pre boil volume of 51 litres. Post boil volume was 44 litres but I only ended up with 33 in the fermenter. I lose about 3.5 litres to trub and abouit .5l in my chiller and hoses which leaves alot of loss to cooling and shrinkage.

Something isnt adding up here?

 

[Mercs Own]

Okay so I am repling to myself - which is a worry. I talk to myself too!!

In BeerSmith if I enter in all of the figures under equipment/ boiler I get:

boil volume: 51
loss to trub and chiller 4.5litres (as measured)
cooling loss 4% = 1.38 litres
tot in fermenter: 33 litres

which leaves a boil off loss of 23.8% = 12.14litres :excl: :beerbang:

I am not doing a full burner boil nor what I would consider to be an overly physical boil.

I do not leave the lid on whilst it comes up to a boil - would I be losing a lot to evaporation there???

I have done three brews so far with 33litres in Fermenter 1st brew, 35 in the fermenter 2nd brew - I tipped the boil kettle to get a bit more liquid and 3rd brew 33litres.

How vigarous should the boil be?

edite: my calculated boil rate is 14% 51 pre boil - 44 post boil =approx 14%

 

[sluggerdog]

You seem to be loosing a lot, I usually end up with around 22 litres and I am boiling 28 or so litres.

I also tip the kettle to get the last drops out of it.

With the boil, the bigger the better I find.

Oh and I also leave the lid off the whole time now, I used to have it on while it was getting up there and took it off when it was boiling but now I have a NASA burner it only takes me 15 mins to get it going.

Maybe try with the lid on until it starts to boil and see if this makes any difference, I would say if it did make a difference it wouldn't be much

 

[Gulf Brewery]

Hi Paul

I think you have miscalculated your losses or water measurement somewhere. I would start with 44 litres of water in the kettle and the fill your fermenter from that as a test. The you can go and accurately measure where you are losing water. I mark a container in 4 or 8 litre increments and fill my kettle(s) from that when I want to do accurate measurements.

Water is a lot cheaper than wort and easy to measure as it ain't boiling. Don't forget your 4% shrinkage from boiling to cold when you do your final corrections.

Cheers
Pedro

 

[sosman]

If you are losing 11 L after the boil then I would consider that high. I leave quite a bit in the bottom of my kettle (I could drain more but with trub) and it is still only 4-5 litres.

 

[chiller]

Okay so I am repling to myself - which is a worry. I talk to myself too!!

In BeerSmith if I enter in all of the figures under equipment/ boiler I get:

boil volume: 51
loss to trub and chiller 4.5litres (as measured)
cooling loss 4% = 1.38 litres
tot in fermenter: 33 litres

which leaves a boil off loss of 23.8% = 12.14litres :excl: :beerbang:

I am not doing a full burner boil nor what I would consider to be an overly physical boil.

I do not leave the lid on whilst it comes up to a boil - would I be losing a lot to evaporation there???

I have done three brews so far with 33litres in Fermenter 1st brew, 35 in the fermenter 2nd brew - I tipped the boil kettle to get a bit more liquid and 3rd brew 33litres.

How vigarous should the boil be?

edite: my calculated boil rate is 14% 51 pre boil - 44 post boil =approx 14%

[post="86658"][/post]​

Hi Paul,

I just put the figures you gave me into BS and assuming I'm not too much in weekend mode -- your evapouration is 23%. This doesn't suprise me at all IF the kettles are similar opening size to mine.

I altered one of the lids to restrict the evapouration to about 14% by removing about 1/4 off one side.

I have a lid for my boiler now that has a section removed.

Because of the larger surface area you have with your pots, compared to a modified keg, even though the boil may not look overly rapid the evapouration is very high.

To reduce the evapouration just cover the pot so only 1/4 is open and that should reduce the evaporation and help you with your calcs. Remember though the pot will now want to boil more vigourously so adjust the flame down


Steve

 

[Bilph]

I find my losses during the boil are higher than the 10% most seem to get. 15% regularly and even 20% is not unusual. Boil time is usually 75 minutes.
A rolling boil is what I've been told to maintain. That just means enough to keep things moving, i.e an obvious circulation of the wort. The "waves" on the surface are probably 1cm-1.5cm.
I never worry too much about losses during the boil as I figure it's only water being driven off anyway. Consistent mash efficiency means I can hit target volumes and gravities without too much fuss.

 

[Jazman]

i loose around 3 litres in trub but have a evap of about 15 % in a s/s vessel ,small opening but it will change soon with the new kettle

 

[vlbaby]

i always seem to have high evap rates also. Around 20- 30 % per hour. I dont know how to explain this except for maybe i am boiling too vigorously.

vlbaby.

 

[Mercs Own]

The thing that confuses me here is that the pre boil rate and the post boil rate actually equal an evaporation rate of 14% I measue this prior to whirlpooling. It would seem excessive if I lost another 9% whilst waiting the 20 minutes for the whirlpool to settle? Next brew day I will put the lid on after whirlpooling and seeing if that makes a difference! That wont cause any off flavours will it.

Will do a cold water test today to make sure my dip stick is accurate.

 

[Jazman]

i put a santised lit on me kettle when i finished and have no probs but then i have never had losses of what you are gettting fromwhen u finishd boiling

 

[Peter Wadey]

Merc,
Sorry for the obvious qn, but...
How are you determining the kettle volumes in litres?

I am just wondering if you might be doing conversions from US Gall to litres incorrectly.

If the kettle is marked in US Gallons and you make the mistake of assuming 4.54 litres per US Gallon, then you will think you had more in the kettle than you actually did. 1 US Gallons = 3.79 litres.

The fermenter on the other hand will be locally made and probably marked correctly. When you fill her up, the losses seem more than expected.

If we make the assumption above, then

then your preboil of 51 litres is actually only 42 litres
your postboil 44 litres is actually only 36.7 litres

which approaches your collected volume, with some allowance for hose and trub loss

Rgds,
Peter

 

[beer slayer]

Hi Merc
I too have losses from 4 to 8lts. Last mash I did I had approx 30 32lts in my boiler and ended up with about 19lt. With taking into account my losses etc I should have ended up with approx 24lt. I use a 50lt SS keg for my boil the opening is as wide as the keg. The boil is a good roiling boil. Its hard to imagine that I would lose that much volume. Im also looking for answers on this one :blink: . Would just leaving a lid on the boiler reduce the loss that much???
:beer:

 

[Pumpy]

Paul,

What I have been doing with the the remains in the kettle is run it through a 10 micron nylon filter bag place the wort in a gallon jar put some Glad wrap around the top place it in the fermenting fridge for a day then siphon off the clear wort give it a good shake to aerate it and just add it back to the fermenter and I often use some of it for cultivating my next starter which I just tip into the next batch.


Pumpy

 

[Mercs Own]

Peter, thanks for stating the obvious but thankfully I was on to it from the start and have done the correct measurement worked out on 1us gallon = 3.79 litres.

I have a dip stick on which I have 1 litre marks across. I have just done a test for it's accuracy and it is absolutely zoned in correctly.

Beerslayer just to confirm - do not leave the lid on during the boil but after you have whirlpooled.

Thanks for the idea Pumpy - sounds like a bit of effort but I may consider it. Firstly I want to work out where I am losing that extra 9% of my wort?!!

 

[Wortgames]

Paul, so you are measuring 51L pre boil and 44L post boil?

That's 7L to evaporation which is about 14%. That sounds pretty good to me for a good rolling 60 min boil and an open kettle outdoors. But assuming both are measured against the same scale and at the same temp, then the question is where the rest of it is going. This 44L is becoming 33L in the fermenter. Lets say you're losing 4% to shrinkage while chilling and maybe another 6% to post-boil evaporation, that still leaves 40L.

3.5L is left behind in trub and 0.5 to your chiller and hoses, that should leave you with 36L of the good stuff, so there's still around 3 litres going AWOL.

How large is your sampling jar? :chug:

Have you checked your fermenter graduations? This would be the most obvious culprit as I see it. Alternatively we've just underestimated all of the above losses slightly and you're losing a bit more at each stage.

I guess the only way to be sure is to make sure all of your vessels are all accurately marked, then make notes of volumes and temperatures at each stage of your next brew and post the results.

They do seem like excessive losses post-boil but maybe that's just the way things are with your system.

:beer:

 

[Mercs Own]

Okay, my measurements on my dip stick are out.

The B3 shifts with a manual that states 1.4 inches is equal to one gallon and that the false bottom is 1.75 inches from the true bottom. I did a water test and found the false bottom sits 6 litres off the true bottom and that 1.75 inches = 6 litres therefore 1.75 inches is equal to 4.445 centemeters which is equal to 6 litres therefore 4.445 divided by six is the litre per centremter measure =.75

When I marked my dipstick I rounded the .75 up to .8 which doesnt seem like much but over 51 litres it makes a 3 litre difference. Which means I am boiling more than I thought.................

I am going crazy!!! I thought I put 40litres in my boiler - it measured out on my dip stick as 44 but when I emptied it I found I actually had 42 h34r:

My sister is here from New York and she bought me a couple of bottles of Pumpkin Ale - I think I will go and drink them now :blink:

If 1.4 inches equals 1 Gallon how many centremeters equals one litre?

ciao

 

[vlbaby]

0.94 cm per litre

 

[Wortgames]

[maths deleted so as not to upset smart people]

 

[Ducatiboy stu]

My AG system works out at 30ltrs in the kettle to start and 22ltr in the ferm at the end. Takes into account evap,shrinkage and trub loss.