First brew, the silly questions.

[quixoticgeek]

Please forgive my potentially stupid questions, but I am rather nervous of screwing up my first brew. I am looking to make a pretty basic bitter which has 4.5kg of grain as the mash, and a 25L brew length.

How much water do I use in the mash tun? I plan on batch sparging, do I put the remaining of the liquid needed for the brew through the grain bed?

The water calculator suggests I need 28L of water in the boil, but it talks of 14L batches, and then I get very confused.

Can someone explain this one for me please?

J

 

[Moley]

Greetings, and welcome to the forum :

I'll try to explain some of the numbers in a bit, but first I need to bounce some questions back at you:

Have you done some kit brewing already, or are you jumping straight to AG?

What are you using as a mash tun, does it have a tap and a strainer, what's its total volume and have you got your head around losses and dead spaces yet? If you haven't done so already, then I would recommend you read this AG “How To” Guide.


Using your figures in the Batch Sparge Calculator:

Brew length 25 litres
Loss to evaporation I've set at 15%, it will probably be higher but you can water it back.
Loss to hops & trub I've left at 1 litre, but will probably be higher according to boiler dead space.
Total grain 4.5kg
Water : grain ratio 2.5 : 1

Total water volume 36.1 litres
Calculated wort volume 30.6 litres

You want to end up with 25 litres so the calculator says 30.6 needs to go into the boiler because you're going to lose 1 litre to absorption by hops and boiler dead space and the rest is going to boil away.

Calculator works on the basis that your grain is going to absorb 1 litre per kilogram = 4.5 litres + 1 litre of mash tun dead space, so that's where the extra 5.5 litres goes.

Calculator wants you to do two batches of 15.3 litres, so that's 20.8 litres of water for batch #1 (20.8 needs to go in because only 15.3 is going to come out).

Your mash volume is given as 11.2 litres (around 76°C) which is 4.5kg x 2.5

After the (usually) 90 minute mash you open the tun and add a top-up of 9.6 litres (also around 76°C)

Give it a gentle stir, see that “How To” about recirculating first runnings, and then drain the tun to an FV.

Second batch of water then goes on to the grain in the tun (possibly slightly hotter than before, someone else need to advise here) but that is 15.3 in giving 15.3 out because your losses have already been taken care of. Give it a stir, let it stand for a few minutes, recirculate first runnings and drain tun.

It sounds complicated but will make sense when you try it.


If your tun isn't that big you could do three batches of 10.2 litres
First = 11.2 mash + 4.5 top-up = 15.7 in, 10.2 out
Second and third batches 10.2

 

[evanvine]

:clap: :clap:
Very well explained Ade, nicely put. :thumb:

 

[quixoticgeek]

Greetings, and welcome to the forum :

I'll try to explain some of the numbers in a bit, but first I need to bounce some questions back at you:

Have you done some kit brewing already, or are you jumping straight to AG?

I have done a number of kits before building upto AG brewing.

What are you using as a mash tun, does it have a tap and a strainer, what's its total volume and have you got your head around losses and dead spaces yet? If you haven't done so already, then I would recommend you read this AG “How To” Guide.

My mash tun is made from a pair of 60L buckets, with one inside the other, the inner having had lots of 2mm holes drilled in it. This is then wrapped in insulation to keep the warm in. I haven't yet worked out the total dead space volume of it, that is on my list of things to do before brewing.

Using your figures in the Batch Sparge Calculator:

Brew length 25 litres
Loss to evaporation I've set at 15%, it will probably be higher but you can water it back.
Loss to hops & trub I've left at 1 litre, but will probably be higher according to boiler dead space.
Total grain 4.5kg
Water : grain ratio 2.5 : 1

Total water volume 36.1 litres
Calculated wort volume 30.6 litres

You want to end up with 25 litres so the calculator says 30.6 needs to go into the boiler because you're going to lose 1 litre to absorption by hops and boiler dead space and the rest is going to boil away.

With you so far.

Calculator works on the basis that your grain is going to absorb 1 litre per kilogram = 4.5 litres + 1 litre of mash tun dead space, so that's where the extra 5.5 litres goes.

Calculator wants you to do two batches of 15.3 litres, so that's 20.8 litres of water for batch #1 (20.8 needs to go in because only 15.3 is going to come out).

This is where I get confused, two batches to sparge the Mash tun? or is this one batch of 15.3L goes into the MT for the actual Mashing, then the second 15.3L is used to sparge the grain in the MT?

Your mash volume is given as 11.2 litres (around 76°C) which is 4.5kg x 2.5

After the (usually) 90 minute mash you open the tun and add a top-up of 9.6 litres (also around 76°C)

Hold on? So I mash with 11.2kg to start with, then add 9.6L, then drain that into the boiler (via recirculating the first runnings), THEN I sparge with the remaining 15.3L?

Give it a gentle stir, see that “How To” about recirculating first runnings, and then drain the tun to an FV.

Second batch of water then goes on to the grain in the tun (possibly slightly hotter than before, someone else need to advise here) but that is 15.3 in giving 15.3 out because your losses have already been taken care of. Give it a stir, let it stand for a few minutes, recirculate first runnings and drain tun.

It sounds complicated but will make sense when you try it.

If your tun isn't that big you could do three batches of 10.2 litres
First = 11.2 mash + 4.5 top-up = 15.7 in, 10.2 out
Second and third batches 10.2

My mash tun has a volume of 60L, I have designed it so that I can do high gravity mash's for 10G batches if I want to, although I am working on 5G(ish) brew length at first, so I don't waste so much ingredients if I screw up.

It's starting to make a bit more sense, I think. How much room is there for screwing up? Is it possible to over sparge?

J

 

[Moley]

Hold on? So I mash with 11.2L to start with, then add 9.6L, then drain that into the boiler (via recirculating the first runnings), THEN I sparge with the remaining 15.3L?

Bingo :thumb:

Your mash liquor in litres will usually be around 2.5x the weight of the grain, then the top-up is added to give your first batch volume, then you take a second wash.

It's starting to make a bit more sense, I think. How much room is there for screwing up? Is it possible to over sparge?

It can be quite a steep learning curve but you're obviously getting your head around it quite well already. Good idea to start with a smaller batch though.

You can over sparge, but when you need them we can point you towards calculations for yield. Suffice to say for now that you should be able to get around 25 litres at about 1.040 from your 4.5kg.

 

[evanvine]

Ade, you're a star!