Consistently Lower Bottling Volumes

[chrisluki]

Hey guys

I still don't think I fully understand what affects the efficiency of my brew set up, I think I fixed the Mash Temp issue i was having recently but still got a less than stellar final volume with my brew this week.

Brewed my Lavaman Red Ale this week with these details:
5.75kg grains milled with my drill powered 2 roller mill, set to the width of a credit card
Mash in with 15l for 45 min
Drain off liquid to kettle - I dont measure this volume, but maybe i should?
Sparge in with 14l for 15 minutes
Drain off liquid to kettle - same as above
Bring to boil and then boil for 60 minutes
Transferred approx 14-15 litres to Fermenter, Beersmith estimates i end up with 19l...that's a big difference.

What are the key areas that you lose volume from? If i mill my grain coarser will that soak up less water but maybe change my gravity reading? Does the time taken to actually get liquid up to the boil change the final volume?

Cheers for any pointers

Chris

 

[manticle]

Measure all points at least once so you get an idea where and how much your losses are. Basically after mashing you will get loss to grain absorption, and loss to deadspace.

In the boil you get loss to evaporation and loss to trub and deadspace. You also lose some volume when the wort cools and contracts.

Once you know what the mash losses are and the boil losses, you can work backwards to find target pre-boil volume and backwards again to work out required sparge volume and, depending on desired mash in ratio, required strike volume.

 

[chrisluki]

Measure all points at least once so you get an idea where and how much your losses are. Basically after mashing you will get loss to grain absorption, and loss to deadspace.

In the boil you get loss to evaporation and loss to trub and deadspace. You also lose some volume when the wort cools and contracts.

Once you know what the mash losses are and the boil losses, you can work backwards to find pre-boil volume and backwards again to work out sparge volume and, depending on desired mash in ratio, strike volume.

Thanks for this, i will measure everything next time.

When you talk about deadspace, is that the leftover liquid that sits below the tap in your kettle etc?

 

[DJ_L3ThAL]

What is loss to dead space in terms of volume? Can't get my head around that sorry?

Edit.... Ahhh, volume you can't get out due to tap height. So for a 1V BIAB type setup there is no loss to dead space during the mash, but is from kettle, combined with trub.

 

[seamad]

Pointer #1...start measuring everything, unless you have some numbers you aren't going to figure anything out.
Allowing a very rough 1l/kg grain absorption and with some tun deadspace loss you should be getting @ 22l into the kettle preboil, If you get a 10 % boil off rate then you should have @ 20l after a 1 hour boil. With the 14-15 you are getting my first guess is that your boil off rate is probably high.
I used a measuring jug ( 5l one ) when I first marked off my HLT and kettle and my numbers weren't quite right, I decided to put the jug on my grain scales and weigh out 5kg (5l) and found the jug was out 800ml, which is a very significant error when using @ 65l water for a brew.

 

[DJ_L3ThAL]

+1 for weighing your brew water!

 

[manticle]

What is loss to dead space in terms of volume? Can't get my head around that sorry?

Edit.... Ahhh, volume you can't get out due to tap height. So for a 1V BIAB type setup there is no loss to dead space during the mash, but is from kettle, combined with trub.

Yep.

In OP's case it sounds like 2 or 3v as he is draining to kettle preboil.

 

[chrisluki]

Pointer #1...start measuring everything, unless you have some numbers you aren't going to figure anything out.
Allowing a very rough 1l/kg grain absorption and with some tun deadspace loss you should be getting @ 22l into the kettle preboil, If you get a 10 % boil off rate then you should have @ 20l after a 1 hour boil. With the 14-15 you are getting my first guess is that your boil off rate is probably high.
I used a measuring jug ( 5l one ) when I first marked off my HLT and kettle and my numbers weren't quite right, I decided to put the jug on my grain scales and weigh out 5kg (5l) and found the jug was out 800ml, which is a very significant error when using @ 65l water for a brew.

This sounds like a great idea...my 5l jug was a cheapy, so it could very well be dodgy...i will measure the weight of it when full.

I think, just from knowing my 50l keg is near half full, that my boil liquid would be near the 22l mark...so maybe my boil off rate IS high? How do you fix that?

 

[seamad]

You don't "need" to fix it so much, just know it. However 10 % would be the minimum I'd aim for. On my system I have a 6l/hr rate which is @ 11.6 %. Mine is electric and I can adjust the % output to the 2 elements ,and being electric it's very consistent brew to brew, if you are on gas just adjust and try to get a consistent rate for each brew, Your brew software should have boil off rate/volume you can set.

 

[takai]

Kind of on topic, but anyone have some decent methods for measuring scales in their setups? I used to have a stainless ruler pop riveted to the side of my old keggle, but it became a pain to clean. Thinking of options for the new setup now.

 

[DJ_L3ThAL]

Superoo (Eaton Laser) does an ABS or other food grade plastic ruler if you provide the dimensions of your kettle. Easier for cylindrical pots. Reminds me I want one!

.................SCRATCH THAT! Looks like it may have been removed from his website - will send a PM!

 

[seamad]

Kind of on topic, but anyone have some decent methods for measuring scales in their setups? I used to have a stainless ruler pop riveted to the side of my old keggle, but it became a pain to clean. Thinking of options for the new setup now.

there was an etching thread here awhile ago, looked very smart.

 

[Bridges]

Superoo (Eaton Laser) does an ABS or other food grade plastic ruler if you provide the dimensions of your kettle. Easier for cylindrical pots. Reminds me I want one!

.................SCRATCH THAT! Looks like it may have been removed from his website - will send a PM!

Here it is.

 

[DJ_L3ThAL]

Food grade acrylic, would that be suitable at post-boil temps?

I can find the melting point is 160C, but I assume it would warp/soften prior and potential leech nasties in at lower again?

EDIT: Not having the most articulate night... the wort gauge rules measure by holding the end ABOVE the wort level and then measuring against the pot edge... so temperature rating irrelevant.

 

[Tahoose]

Kind of on topic, but anyone have some decent methods for measuring scales in their setups? I used to have a stainless ruler pop riveted to the side of my old keggle, but it became a pain to clean. Thinking of options for the new setup now.

Work out how big the volume of your pot is using this

http://www.handymath.com/cgi-bin/circlevali25.cgi?submit=Entry

Then go and buy one of these

http://www.bunnings.com.au/craftright-600-and-300mm-stainless-steel-ruler-2-pack_p5660462

(1000mm = $15) for all of you mega brewers

Divide your total liquid volume by cm in height. You should end up with a litre/cm number. Dip it in and take a measurement, then calculate, its easy as, also the easiest thing in the brewery to clean.

My boil pot is 50cmx50cm so it's pretty easy. 1cm/2litres

 

[chrisluki]

Just getting things back on track, slightly!

So it seems I have a very dodgy measuring jug! When I measured the weight of the "5 litres" of water in my jug, to my surprise it weighed in at 4.72kg!!!

I transfer the water from my HLT to my mash tun with this jug, so for most brews I have been cheating myself out of approximately 1.5 litres of water!

I am guessing this will be messing with not only my gravity readings, but also my efficiency!!

Time to buy a new jug!!!!

 

[takai]

Work out how big the volume of your pot is using this

http://www.handymath.com/cgi-bin/circlevali25.cgi?submit=Entry

Then go and buy one of these

http://www.bunnings.com.au/craftright-600-and-300mm-stainless-steel-ruler-2-pack_p5660462

(1000mm = $15) for all of you mega brewers

Divide your total liquid volume by cm in height. You should end up with a litre/cm number. Dip it in and take a measurement, then calculate, its easy as, also the easiest thing in the brewery to clean.

My boil pot is 50cmx50cm so it's pretty easy. 1cm/2litres

Thats what i currently use. Was wondering if there was a nicer method. I see sight tubes etc all the time on photos, but they all look like pains to clean.

 

[Pogierob]

Just a question in relation to the OP.
what was your gravity like?

Planned vs actual?

 

[chrisluki]

Just a question in relation to the OP.
what was your gravity like?

Planned vs actual?

That's the thing i cant work out...OG's have just about been spot on lately...its's the FG's that i have been having trouble hitting...consistently higher...maybe there is a link here?

 

[paulyman]

That's the thing i cant work out...OG's have just about been spot on lately...its's the FG's that i have been having trouble hitting...consistently higher...maybe there is a link here?

Are you saying that the OG into the fermenter is spot on, but it finishes fermenting higher than you are expecting? Wouldn't that suggest you are mashing higher than planned?

Or are you saying that your pre boil gravity is spot on but your gravity in the fermenter is higher? That combined with a lower volume would probably be a higher than predicted boil off.