Full volume Mash. How does that work?

[The Green Man]

I am a perplexed brewer. I keep reading about how full volume mash in the one kettle is the true BIAB method and I just don't get it. I can't do this because I a have a small set-up, but if I could get a bigger kettle I'd like to understand how it works.

My confusion stems from the mash-water ratio. If this is 2 litres to 1 kilogram, surely full volume is way too loose a mash.

I understand that sparging fills this gap. But, in true BIAB, there is no sparge apparently.

My next brew has 2.2kg of MO and 4 litres of water for mash and 6 litres for boil. Currently, I sparge in 2 litres to get to boil volume. I am unusual in that I water down my wort post cooling to get my target volume in the fermenter (my pot/kettle is 7 litres max). For normal brewers though doing full volume isn't the mash too loose?

I must be missing something simple. Would appreciate someone providing the missing link so I can link the dots up.

 

[okoncentrerad]

I don't have any link, but as I understand it you can more or less do as you like, "true" BIAB or not. My experience is limited, only 6-7 brews so far, but I've done thicker mash and loser mash and also full volume mash, and I've seen no big difference in efficency. With my limited knowledge the only thing I can think differs is that depending on your water it could be more difficult to hit the numbers on pH etc.

 

[The Green Man]

Thanks. I thought I read somewhere about too loose being bad for efficiency, but maybe not. Just need to get a bigger pot by looks of it.

 

[okoncentrerad]

I'm sure others here have better insights in this than we have though let's wait and see if better answers pop up!

 

[jeffpn]

My first BIAB was a 5 gallon kit that Brewers Best sold. If I recall, they said to bring 7 gallons of water to 151-153°F and then pour the grains in the bag. At the end of the mash, they say to pour 1 gallon of water over the grains for a sparge. They assume a 1 gallon boil off, so at the end, there are 6 gallons of wort (8 gallons of water with 1 gallon each lost to grain absorption and boil off) . They never mention a grain to water ratio specifically. I got around 80% efficiency, which I was pleased with.

 

[KC]

I keep reading about how full volume mash in the one kettle is the true BIAB method

I would question these sources. Anyone who claims there's "one true way" of anything is usually full of crap.

Mash ratio is not a fixed standard. You can fit up to 0.26kg grain per L of total kettle volume for a thick mash and still get over 80% efficiency.

 

[soccerdad]

To some extent BIAB challenges the old brewing myth that 'the best mash has a ratio of x to y, and is subsequently 'best sparged or rinsed with z gallons of sparge water at t temperature.

While the above method is tried and true and makes great beer, it is not the only method as the BIAB experimenters have shown.

It just combines the separate mash water and sparge water into a full volume mash.

 

[The Green Man]

RIP sparge. Just get a bigger pot and chuck it all in. Job done....as I only have a small pot I will have to continue to sparge though...

So, I take it when I read about MaxiBIAB that is BIAB with a sparge? Or, has someone just made that up? Of course, everyone has their own way and I'm sure most are pleased with their results whatever method they use. It's all kind of academic really.

Love the way brewing is so diverse and that so many ways of doing things are embraced and old rules are routinely shoved aside and/or played with. Exciting stuff.

 

[jeffpn]

All ya gotta do is convert the starch to sugar and get the sugar into your brew pot. The method is up to you!

 

[KC]

when I read about MaxiBIAB that is BIAB with a sparge?

From what I understand of MaxiBIAB, yes. It works the same way I used to do BIAB, but I never used that term. Mash thick in a small pot, sparge enough to replace the grain absorption loss, boil thick, then dilute to target OG at the fermenter

 

[Nosybear]

Thanks. I thought I read somewhere about too loose being bad for efficiency, but maybe not. Just need to get a bigger pot by looks of it.

I don't think efficiency is too much of a concern at our scale. I'm not a BIAB brewer but offer this: We end up buying another few ounces of grain to make up for lost efficiency, no big deal. As Jeffpn says above, the goal is sugar in your pot.

 

[Hawkbox]

I personally no sparge, just dump the entire load of water into the cooler for a 5 gallon batch. My cooler isn't big enough to do that with a 10 gallon batch so I batch sparge.

 

[jmcnamara]

From what I understand of MaxiBIAB, yes. It works the same way I used to do BIAB, but I never used that term. Mash thick in a small pot, sparge enough to replace the grain absorption loss, boil thick, then dilute to target OG at the fermenter

This is exactly what I did in my 5gallon kettle. The last 2 batches I brewed in a new 10 gallon one, I did a full volume mash. Beers are still fermenting, so don't know how it'll effect things

 

[The Green Man]

Mash thick in a small pot, sparge enough to replace the grain absorption loss, boil thick, then dilute to target OG at the fermenter

That is my method exactly. Mash and boil thick. Then water down in the fermenter.

 

[The Green Man]

This is exactly what I did in my 5gallon kettle. The last 2 batches I brewed in a new 10 gallon one, I did a full volume mash. Beers are still fermenting, so don't know how it'll effect things

Let me know how it goes. By sounds of it efficiency is broadly similar...but what a saving in time and effort.
In the UK, I am going to invest in a bigger pot for sure. Time to upscale.

 

[thunderwagn]

This is a great BIAB calculator. Fill in the blanks and sparge to zero if you want to go full volume mash. I used it for a couple of yrs doing biab and still use it on my batch sparge set up. This calc will also give you 1st running estimates if your into such in a sparging set up ( I am). Great calculator. I use it all the time in conjunction with BF.
https://pricelessbrewing.github.io/BiabCalc/#Advanced

 

[GFHomebrew]

pretty much everything has been said that i would of already in this thread. its not all about efficiency but consistancy me thinks. ive personally found my full volume Biab batches are less efficient in brew house than sparging. not sure exactly why my thoughts are sparging rinses sugars from grains. another thing ive herd but not personally found from full volume Biab is a more full bodied beer. so @jmcnamara itll be interesting how your full volume beers compare to your old method .

oh last one my water to grist is 1kg grain to 6lt of mash water i consistently get 80+ efficiency so i believe water grist ratio doesnt matter much. cheers good luck green man and yes get a bigger pot= easy boil

 

[Nosybear]

100% correct on the reason for the BIAB efficiency loss: It's difficult to sparge well. Water to Grist ratio is another of those things that matter to the big guys trying to squeeze every molecule of sugar possible out of the grain, to us, not so much. I generally work with half the water in the mash, half in the sparge and no concern at all about the ratios.

 

[The Green Man]

Just for everyones interest, I did a brew yesterday, the olde worlde ipa, and tried a very thick mash 2:1 (4.5l:2.2kg). Ended up losing so much heat I had to add another 2l of near boiling water and even then couldn't hit my target temp. Mashed by dumping the bag in the fermentor and adding 2l of 80c water, stirred and let it sit for 10 minutes. Got decent efficiency this time, but could be better. Ended up getting 8 litres into the fermenter at 1.064 (rather than the 1.070 I was aiming at, was too confident in calculations...). Still happy with that.
However, I need a bigger pot and more consistency. Let the brew learning continue!
Cheers for all the input fellas.

 

[thunderwagn]

Just for everyones interest, I did a brew yesterday, the olde worlde ipa, and tried a very thick mash 2:1 (4.5l:2.2kg). Ended up losing so much heat I had to add another 2l of near boiling water and even then couldn't hit my target temp. Mashed by dumping the bag in the fermentor and adding 2l of 80c water, stirred and let it sit for 10 minutes. Got decent efficiency this time, but could be better. Ended up getting 8 litres into the fermenter at 1.064 (rather than the 1.070 I was aiming at, was too confident in calculations...). Still happy with that.
However, I need a bigger pot and more consistency. Let the brew learning continue!
Cheers for all the input fellas.

Out of curiosity, did you hit your stike temp when adding the grains?