Partials Volume

[Dylfish]

Just wondering, ive read its 2.5 of water to 1 kg of grain used.

Im aiming to get a 20 ltr brew going, so does that mean ill need about 8kg of grain? or does the LME come into this somehow?
i think ive confused myself to hell with these partials.

sorry for all the stupid questions of late.

 

[Pennywise]

LME is part of the fermentables so unless your making a whopping big brew I doubt you'll need 8kg for any 20L partial. Post up the recipe so we can help withouth any confusion

 

[Dylfish]

http://www.aussiehomebrewer.com/forum//ind...amp;recipe=1032

is what im looking at, im just wondering how to work out what quanities I need for certain volumes?

(ok i just saw the volume is 22 ltrs, but its more of me understanding ratios and scaling)

 

[MarkBastard]

Mash the actual grain (which is 2.1kg in that recipe) in about 8 litres of water and dunk sparge with another 2 litres.

Put the LME in at flame-out.

Top up with water to 21 litres or whatever your desired volume is when you put it into the fermenter.

 

[Dylfish]

Mash the actual grain (which is 2.1kg in that recipe) in about 8 litres of water and dunk sparge with another 2 litres.

Put the LME in at flame-out.

Top up with water to 21 litres or whatever your desired volume is when you put it into the fermenter.

ok is there a way you came up with that? or just experience?

 

[manticle]

Water to grain ratio is usually calculated between 2.g - 3 kg per litre. Grain absorbs around 1 litre per kilo when first mashed.

What you need to do is calculate how much soaked grain you can fit in whatever vessel you are mashing in and how much final volume you want.

Then for each kilo minus 1 litre for first runnings of total liquid added. I'm not amazingly familiar with BIAB so I don't know how different sparging or anything else is but with trad brewing you would then rinse the grains with hot water to make up the boil volume. I usually work on making around half my final volume the amount of sparge water I use. I also mash out with 8-10 L which accounts for my losses due to grain absorption but maybe don't worry about mash out for a partial as you will be topping up with extract and more water anyway. If you sparge several times you may need to watch gravity and pH as my understanding is that too low gravity (say around 1010 which is pointless extracting anyway) or too high pH can lead to tannin extraction. Temperature can also be something to watch, particularly as pH rises.

How are you mashing? Let us know your intended process and we can help guide you through. It can be difficult to get your head around when you start but the processes are quite simple.

Also if you are following that linked recipe just either use the amounts of grain shown with a 2.5 ratio of water or scale the percentages to suit a different volume.

 

[MarkBastard]

ok is there a way you came up with that? or just experience?

The grain to water ratios that people talk about refer to traditional mashing where you sparge and mash-out afterwards.

Partials are usually done BIAB style, where the ratios are minimums if nothing else. You can use more water if you want to. Hell you can even use 22 litres for your partial if you can actually boil that much, but it begs the question why not do an all grain then?

So 8 litres I think is more than enough for grain to water ratios (as it's 4 to 1), and it will be easier to boil and allow you to get some higher efficiency from the grain with a dunk sparge of 2L. I chose a dunk sparge of 2L because if you fill up and boil a kettle which is usually 1.5L, and then add 0.5L of water from the tap, you will probably get your desired dunk sparge mash out temps just using a kettle (about 77 degrees IMO). So you can empty the boiling kettle into a smaller pot, put 500ml of water from the tap in, make sure it's about 75-80 degrees (ideally 77) and drop your BIAB grain bag into this second pot and give it a good stir and let sit for 5 minutes. Then hoist, squeeze all the goodness out of the bag and tip the liquid into the main bot and start your boil.

That's what I used to do.

IMO it's good to have as small a boil as possible so your stove can definitely handle it. 10L is about as much as my stove could handle using the wok burner on my 19L Big W stainless steel pot.

 

[Dylfish]

The grain to water ratios that people talk about refer to traditional mashing where you sparge and mash-out afterwards.

Partials are usually done BIAB style, where the ratios are minimums if nothing else. You can use more water if you want to. Hell you can even use 22 litres for your partial if you can actually boil that much, but it begs the question why not do an all grain then?

So 8 litres I think is more than enough for grain to water ratios (as it's 4 to 1), and it will be easier to boil and allow you to get some higher efficiency from the grain with a dunk sparge of 2L. I chose a dunk sparge of 2L because if you fill up and boil a kettle which is usually 1.5L, and then add 0.5L of water from the tap, you will probably get your desired dunk sparge mash out temps just using a kettle (about 77 degrees IMO). So you can empty the boiling kettle into a smaller pot, put 500ml of water from the tap in, make sure it's about 75-80 degrees (ideally 77) and drop your BIAB grain bag into this second pot and give it a good stir and let sit for 5 minutes. Then hoist, squeeze all the goodness out of the bag and tip the liquid into the main bot and start your boil.

That's what I used to do.

IMO it's good to have as small a boil as possible so your stove can definitely handle it. 10L is about as much as my stove could handle using the wok burner on my 19L Big W stainless steel pot.

thanks guys, im going to go the BIAB route, i think the processes are simple but its just hard to follow

and if i have 8ltr of wort at the end of my boil, wont the remaining 15 odd ltrs of water dilute the final product?

 

[MarkBastard]

thanks guys, im going to go the BIAB route, i think the processes are simple but its just hard to follow

and if i have 8ltr of wort at the end of my boil, wont the remaining 15 odd ltrs of water dilute the final product?

The 8 litres you end up with is going to be very concentrated, so you actually want to dilute it with the water!

Think of it this way, the grain is for the first 10 litres, the liquid malt extract is for the water you add.

 

[Dylfish]

*taps nose*

thanks guys!

 

[Noxious]

Not to thread hi-jack but I'm a bit confused as to why is it ok to rinse/sparge the grain in water hotter than your mashing temps, when I've always heard that high temps can extract tannins.
Is the possibility of tannin extraction during sparging removed after the initial mashing or something?
Cheers all

 

[manticle]

As far as I understand it the risk is only when the pH is too high. Thus if you oversparge and sparge hot you are at risk of extracting tannins. Decoctions boil a portion of the grains with no risk of tannin extraction although its not recommended to boil grain instead of steep so I'm not massively clear on it all. Sparge water for me is around 78-80. The hotter water dissolves the remaining sugars into solution better as well as stopping enzyme activity (particularly if you mash out first).

 

[marksfish]

if your sparge water is at 75 degrees the overall temp will drop when you add the bag of grain.

 

[Dylfish]

hey guys, ive just scoured at home and the only ss pot in have suitable is a 10.1 ltr pot. too small?

 

[marksfish]

big w has light s/s 19 litre pots for 20 bucks used mine for ten extract and five partials before i went biab and i still use it to heat water for mash-outs.