Wort Extraction

[Kanetoad23]

Hi All,

I have been running a few AG and I'm trying to get my head around it.

I have converted an old esky into a mash tun which seems to be working well, but how much wort should i expect to produce? In past trys I don't seem to be extracting much.....beer still turning out ok though.

This is the grain bill (from recipe) that I want to use today:

2 Row Pale Malt 3.8kg
225gr Carapils
225gr Light Malt

It asks me to use 10lt in the initial mash and 10 in the sparge and then top up the fermenter to 23lts. It seems that I am using a lot of water to top up to 23lts (approx 12lts on last brew day)

Any advice, or sounds allright?

Cheers

Mark

 

[manticle]

How big is your esky and what strength/gravity wort are you trying to produce?

And what is "it"?

Doesn't sound right - you shouldn't need to top up unless you are making partial mashes in smaller equipment.

 

[QldKev]

You have about 4.3kg of grain. So allowing rough rule 1kg holds 1L water.

10L plus 10L minus 4.3L = 15.7L of wort total

Then say your boil off rate is 15%,
15.7 * .85 = 13.3L post boil.

Then how much wort are you leaving in the bottom of the kettle?
Say a bit over 2L?
So maybe only 11L into fermenter.

23L - 11L = 12L top up

 

[Kanetoad23]

So the maths sounds about right, but is this a lot of water to be topping up with? Won't this dilute the beer a long way?

And also a nother noob question.....should I not be pouring the entire contents of the kettle into the fermenter?

Appreciate your feedback and help.

 

[manticle]

How big is your esky?

 

[Kanetoad23]

Esky is about 30lts

 

[manticle]

You can easily make a full size (20-25 L) batch of anything up to about 1080 in that. No need to top up.

Mash in with 2.5 - 3 L of water per kg of grain. Your grain will absorb roughly 1 L per kilo as suggested by Kev. You will also have some loss in the esky (stuff below the tap etc).

eg. I use a 26 L esky and lose roughly 2 L. To account for this, I preheat my esky with ~2L of boiling water (dissolve my brewing salts in this) befoe mashing in. If using a 5kg grain bill, I then mash in with around 12 L of water.

Drain your first runnings into your kettle after mashing and recirculating.

Now if you are batch sparging, calculate how much more you need to get the appropriate pre-boil volume. You can do this in two stages if your esky is not big enough. You will need to know the evaporation rate of your system and your loss to trub.

eg. If I get 12 L from my first runnings and I know I need 32 L preboil to get 22 L into my cube, I need to batch sparge with another 20 L (no need now to account for grain absorption). I may need to do this in two goes to fit in the tun.

If you are fly sparging, you just sparge until you get the right volume AS LONG AS - your pH doesn't drop too low. Gravity of the runnings should be above 1010 if fly sparging as a rough indicator of pH (or measure pH).

Get your boil volume where you need it, no need to top up. You can fit way more grain in your esky. As I asked in my first post - what gravity wort are you trying to produce?

 

[Ducatiboy stu]

Batch or fly sparge....does not really matter. For a 22lt brew you need to sparge untilk you get enough in the kettle to take into account evaporation losses and cooling shrinkage. Your initial SG will be lower in the kettle before your boil

 

[TidalPete]

You still haven't told us what "it" is? Sounds like brewing software that hasn't been set up correctly?

Like the others say, keep on sparging until you reach your pre-boil volume OR your sparge runnings reach 1.12\1.010

Don't forget to mix your first runnings\sparged wort properly before taking your pre-boil OG as the first runnings are heavier & sink to the bottom of the kettle.

Post 7 advice looks good.