Full volume BIAB with no sparge

[GHW]

So Sunday I will be doing my first full volume BIAB with my gas burner and 33L pot (only done extract in it previously). I've got a Lakeland 'grand remoska' rack as a false bottom, so the bag doesn't squash the hop filter. Fits nicely though a bit pricey at £9.99 but ordinary cake racks weren't high enough to clear the filter.

Anyhoo, the thing I wanted to ask was...

If I'm doing a 20L brew, with a 4.5K ish grain bill, how do I calculate my mash water volume?

Given the grain volume and pan size I was thinking about 25L mash water. I want to do a no-sparge BIAB as dont really have anyway of separately heating any volume of sparge water while I use my pot to mash in.

I've no idea how much water the grain will absorb, or how much I'll lose in the boil, but I figured that I can always top up to the 20L after the boil if I've lost too much.

Any experienced biabers got any suggestions for getting the right final volume in the fv?

 

[rodabod]

It depends on ho much you squeeze the bag, but generally people factor in 0.3-0.4L of water per Kg of grain, so assume you'll lose about 1.5L of water.

 

[mirsultankhan]

So Sunday I will be doing my first full volume BIAB with my gas burner and 33L pot (only done extract in it previously). I've got a Lakeland 'grand remoska' rack as a false bottom, so the bag doesn't squash the hop filter. Fits nicely though a bit pricey at £9.99 but ordinary cake racks weren't high enough to clear the filter.

Anyhoo, the thing I wanted to ask was...

If I'm doing a 20L brew, with a 4.5K ish grain bill, how do I calculate my mash water volume?

Given the grain volume and pan size I was thinking about 25L mash water. I want to do a no-sparge BIAB as dont really have anyway of separately heating any volume of sparge water while I use my pot to mash in.

I've no idea how much water the grain will absorb, or how much I'll lose in the boil, but I figured that I can always top up to the 20L after the boil if I've lost too much.

Any experienced biabers got any suggestions for getting the right final volume in the fv?

Your grains will usually absorb about four/five litres of water max and if you are boiling for an hour (although i cannot be certain as it depends on your set up you have) and usually you lose about five litres due to evaporation during the boil and about .5 litre due to hops. These are just rough guidelines though but they have worked well for me in the past when I was doing BIAB. So if you are doing a full BIAB and planning on getting 20 litres of sweet wort I would be planning on using 28-30 liters of mash water.

 

[rodabod]

Evaporation losses depends on how vigorous you boil, and the circumference of your pot. Assume something like 4L per hour. Top up as required...

 

[GHW]

Ok so I reckon 27L to mash, which will lose me about 2L to grain (going on rodabods rate), then about 4-5L lost to evaporation in boil.

Given its my first go I think I'll aim low, and do 25L, that way if I end up with a low volume of high OG wort I can top up the fv to 20L.

I'd rather do that than end up with more than my target volume of wort and a lower OG.

Thanks dudes

 

[Covrich]

Brew mate will work it out for you if you give it estimates

I am like you in a new setup and my second one I am going to have to adjust from mt first one until I get it right

33L is going on the tight side for 20 liters I think but you should just about squeeze it in. I searched around and people had this problem hence why a lot of people go for 50 liter pots for 23 l brews.

I think you will need probably 27-28liters

Minus 4 for your grain absorbtion
minus a few liters for evap from boil and cooldown
minus a liter or so for hop absorbtion and trub.

You going to mash out or just do a good mash.. I hear some people mash for 90 on these.. I didn't on mine but I rushed mine.

 

[clibit]

I would think you need more than 25 litres cos you lose around a litre per kg to absorption, then you lose maybe 4 litres to evaporation, and a bit more to trub/hops. You don't want to be adding loads when you top up, ideally.

 

[duncans]

but I figured that I can always top up to the 20L after the boil if I've lost too much.

Never done biab but adding some (boiled/bottled) water after the boil is perfectly fine to get the right gravity.

A normal mash is around 2.5 lwater per 1kg grain with the same again for sparging. A spargeless system like spiedel braumeister uses 5l water per kg grain in the mash.

Should be same principal here.

 

[Redron]

I did my first BIAB last week. Aiming for 23L I started with 30 and ended up with 21 after a one hour boil.
Take note, as Covrich said, a 33L pot may be a bit on the small side.... I use a 50 and I still had to be aware of a boil over !
As you said, aim on the low side, you can always top up later, noting Clibit's last comment...
Good luck, I was thoroughly knackered after my first big brew, probably nervous exhaustion !

 

[Spapro]

For this first brew with your lovely new kit I would work back from what you want to finish with:

20litres in FV
= 23 litres at the end of the boil (as you will lose 2-3 litres to hop debris/trub in the bottom of the boiler
= 27 litres at start of the boil
= 32 litres ish mashing water

This will be tight in your 33litre pot so I would go with 28l or 30l for the mash and then top up through the boil with boiling water as required so you have 23litres post boil.

Really worth marking your boiler with some key volume markers for example 23l, 25l, 27l and 30l so you know exactly how much you have in there at any given point in your brew process.

Goog luck with the brew and enjoy !

 

[YeastFace]

I knocked up a spreadhseet when I was doing full volume BIAB.

https://drive.google.com/file/d/0B5COVFYpSUW_NlZLSThhRThYVDA/view?usp=docslist_api

You just need to add specifics for your set up, then it should calculate the pre-boil and strike volumes for you.

Then use an online calculator to work out the strike temp.

 

[Cwrw666]

Ok so I reckon 27L to mash, which will lose me about 2L to grain (going on rodabods rate), then about 4-5L lost to evaporation in boil.

Given its my first go I think I'll aim low, and do 25L, that way if I end up with a low volume of high OG wort I can top up the fv to 20L.

I'd rather do that than end up with more than my target volume of wort and a lower OG.

Thanks dudes

I'd have thought even 25L may be a bit much in a 33L pot as the grain will push the volume way up when you first put it in. I've got a 30L boiler and usually mash with about 20L of water. After the mash I sparge to top up the volume but it's surprising just how much colour and sweetness the sparge washes out.

 

[clibit]

You will lose more like 4 litres to the grain I reckon.

But 4.5 kg grain will only add about 3 litres to the mash volume .

 

[GHW]

Good advice everyone, thanks.

On consideration if all the points raised I'm going for 25L mash, trying to balance full volume for the mash vs over full pot for boil. It'll be a learning experience and I'll need to keep my eye on it and figure out where I can improve next time.

I might do a bit of sparge and see what happens. It'll be 'rustic' though... Probably several kettle loads of water (at 80c) through the grain bag into a separate fv. As long as I get to about 1040 FG I'll be happy. It's a hbc kit so I'm not sure at the moment what my target is, til I open it all up.

I'm anticipating some mishaps.

 

[Redron]

It's all a learning curve.
I did a TT Landlord clone kit and was expecting an og of 1042, I got 1036 despite squeezing the hell out of my suspended grain bag over an FV . Next time I will do kind of a sparge and see that improves my 'efficiency' .

 

[Vallyred]

Good advice everyone, thanks.

On consideration if all the points raised I'm going for 25L mash, trying to balance full volume for the mash vs over full pot for boil. It'll be a learning experience and I'll need to keep my eye on it and figure out where I can improve next time.

I might do a bit of sparge and see what happens. It'll be 'rustic' though... Probably several kettle loads of water (at 80c) through the grain bag into a separate fv. As long as I get to about 1040 FG I'll be happy. It's a hbc kit so I'm not sure at the moment what my target is, til I open it all up.

I'm anticipating some mishaps.

Sparging, however rustic, is so beneficial considering its simplicity.