BIAB question. Sparging

[gone brewing]

When bag drains do the dunk sparg in another pot water temperature does not have to be high to get more sugars without astringency .

I'm with Wynnum. After raising the bag and letting it drain a bit I do a dunk sparge with around 7L of hot water in a stockpot. I let it sit for 5 min, with a bit of a stir then raise the bag from that. In the meantime the urn is going from mash temp up to boiling and as it comes to the boil, the sparge water is ready to be added. As someone else said, if the pot is big enough I wouldn't bother but I have a 30L urn which isn't enough to start with all the water I need so I think if you are going to add a little water through the process, may as well be with a batch sparge.

 

[Mozz]

"Sparge" in progress. Running water through the bag at about 1L a min into kettle as I raise temp to the boil. Kettle volume raised from ~35L to ~50L. The sparged wort coming through the bag is still about 1030 after 10L only dropping to near 1020 towards the end. So in my system it adds a lot in terms of efficiency and tops up the kettle in a no fuss way.

 

[stewy]

So often I hear of colanders, racks on top of the kettle etc with visions of the poor *******s grimacing as their nether regions are getting cooked by hot steaming bag...

"

I find it difficult nowadays to rub one out unless my nether regions are getting cooked by a steaming bag.....


*definitely getting the right amount of sex in my marriage.... Obviously..... Definitely.....

 

[pist]

If your doing full volume i think it's a waste of time
. Big beers approaching the limits of your setup yeah sure but I don't really see the point in doing a sparge on full volume. Just give it a good stirring on the way up to mashout sees me repeatedly hitting my numbers within a couple of points

 

[kingdomplantae]

IMO if your kettle is of sufficient size to do full volume BIAB then just do that, there is not much to be gained faffing around with a dunk sparge or other rinsing of the mash.
OTOH, if your kettle doesn't quite have the capacity to achieve full volume BIAB then a sparge may help you to achieve the greater volume, but some folks just settle on the reduced brewlength.
A kettle volume of around 40L is the threshold for a 23L brewlength, depending on how you determine brewlength and how efficiently the mash performs.

Apologies for reviving an old thread, but the search brought me here.....
I wonder if mashing a smaller volume with an electric urn.would allow for more accurate temp control, especially if a rest step regime employed.... and sparging to ferment volume is viable, with biab?
I find I can fit the entire volume in mu urn, but at that volume element is not quite responsive enough.
Any input appreciated !

 

[BrewLizard]

Seeing as a consistent 85% mash efficiency is possible with an 0.8 mm mill gap and full-volume mashing, you'd really have to be pushing 92-93% for this to be worth it.

Also, temp control is much easier with bigger volumes. If it drops more than 1-2°C in an hour, add blankets until it doesn't.

 

[kingdomplantae]

Seeing as a consistent 85% mash efficiency is possible with an 0.8 mm mill gap and full-volume mashing, you'd really have to be pushing 92-93% for this to be worth it.

Also, temp control is much easier with bigger volumes. If it drops more than 1-2°C in an hour, add blankets until it doesn't.

Thanks for the reply mate, my reasoning is not efficiency, but because I am doing rest steps, I am looking to get better response from my urn element, so for eg the recipe calls for bringing the mash from 35 degrees to 52 over 10 mins and rest there for 15 mins. I don't have a prob holding the temp, but cannot get it up to temp over 10 mins, approx 15 mins would be the best I can achieve... so I was thinking if I reduce my mash volume I can get more responsive temp adjustments..
I am sure I could make adjustments to the rest regime to allow for the time it takes for me to get to the temps but would prefer sticking to the recipe if I can, as I'm pretty new to this.

 

[BrewLizard]

Ah apologies for misinterpreting. Yep, you could do that. Alternative would be to just start your mash about 1-2 L under volume and add boiling water at every step temp increase until you hit the new temp.

 

[kingdomplantae]

Cheers @BrewLizard the Hot water is a great suggestion!

 

[MHB]

It is, but you will need more than the 1-2L mentioned, you can calculate the additions pretty easily, I'm sure there are calculators out there if you don’t want to learn the maths, search for Hot Water Infusions. Its nearly the same equation as calculating strike water temperature.

BIAB is not the easiest system to use if you want to do programmed infusion (heating what’s in the mash tun) as it requires either a pump recirculated wort or a stirred mash to work well. Both are a bit of a PITA when you have a bag in there, seen too many melted bags or bags wrapped around the stirrer. You might be wise to look at one of the many 1V systems on the market.
Mark

PS - Put your hand up if you want the equations
M

 

[kingdomplantae]

It is, but you will need more than the 1-2L mentioned, you can calculate the additions pretty easily, I'm sure there are calculators out there if you don’t want to learn the maths, search for Hot Water Infusions. Its nearly the same equation as calculating strike water temperature.

BIAB is not the easiest system to use if you want to do programmed infusion (heating what’s in the mash tun) as it requires either a pump recirculated wort or a stirred mash to work well. Both are a bit of a PITA when you have a bag in there, seen too many melted bags or bags wrapped around the stirrer. You might be wise to look at one of the many 1V systems on the market.
Mark

PS - Put your hand up if you want the equations
M

Cheers mate for the great info, and yes please post the math if no hassle.

As for purchasing a system, we'll I'm not looking to spend any more money, and luckily havent had to buy much more than empty tallies... trying to make do with what I have.

I'm manually agitating the brew at this stage, which isn't proving too hard, and I'm making sure the bag cannot make contact with the element. I feel I'm getting pretty close, sg, ph, efficiency are all close and wort tastes good.

I'm sure I will end up buying a brew system one day, but want to get my head around the fundamentals before I go balls deep.

 

[MHB]

Ok, it’s all based on the standard mixing equation

Aa+Bb = Cc
Where A+B =C
AB and C are all a value in this case mass
ab and c are a condition.
To give a basic example if we had 5Kg of water at 25oC and we mixed that wit 2L of water at 95oC, plug it in and
5*25+2*95 = 7*c, 125+190=7*c rearrange to (125+190)/7=45oC
We would have 7kg of water at 45oC

We also need to know that malt has a thermal capacity of only 0.4 of water.

From this information we can work out the strike water equation, we use mass as all the units have to be the same ie kg, it’s handy that 1kg water is about 1L.

We modify the mixing equation to allow for the thermal capacity of malt and we get
0.4*Aa+Bb=Cc
Say we had 5kg of malt at ambient temperature say 19oC and we mixed it with 27kg of water at 70oC, we get.
(0.5*5*19)+(27*70)+=32c, 47.5+1890=32c, 1937.5/32=60.55oC

We can rearrange the equation to make it more useful in this case so it tells us how hot we need that 27kg of water to be to hit a selected temperature say we want to mash in at 62oC for a dry beer.
The rearrange equation would look like
Strike water temperature =[((0.4 mass grain)+mass water)*Target temp)]-(0.4mass mass*grain temp)/mass water.
Plugging in
[((0.4*5)+27)*62)-(0.4*5*19)]/27=[29*62-38]/27=65.2oC

OK so now we have a mash at 62oc and we want to add hot water (boiling) to raise the temperature to say 72oC
Remembering that the mash isn’t all water part of it is malt so we need to take its lower thermal capacity into account. what we do is calculate a new combined value called the Mash Heat Capacity (MHC)
It is
MHC=(0.4*Mass Grain)+Mass Water/Grain Mass+Water Mass (total mass)
For the above
MHC=(0.4*5)+27/5+27=0.90625

Nearly there
The following is yet another rearrangement of the above, using MHC keeps it a lot simpler than plugging in all the bits. Looks like -
Mass Boiling Water=(MHC*Mash Mass)*(Target Temp-Current Temp)/Boiling Water Temp-Target Temp.

Note that once taken off the heat, the water droops a couple of degrees very quickly, even pouring from a jug it would be better to use 95-98oC than 100, if going through a hose or transferring from an urn to a jug to the mash 90-95 is probably smarter. Always have a couple of litres more than you think you will need. Let’s plug in 95oc, if you measure carefully and keep records you can get a firm number for your process/system.

We have 35kg of mash at say 61oC we want to raise the temperature to 72oC, how much water at 95oC do we need to add?

=(0.9065*32)*(72-61)/95-77=29*11/23=13.9kg

And therein lies the problem with hot water additions, the hotter the mash and the larger the volume the more hot water you need. It can easily reach the stage where you need much more than you can practically use to get the steps you want.
With careful planning, mashing in thick (say~2.5:1 L:G) you can get two good steps without running out of volume or making the mash too thin.
It does require careful planning.
Mark

 

[S.E]

As for purchasing a system, we'll I'm not looking to spend any more money

If you don't already have one and don’t mind spending a little more money you could get a cheap stock pot for hot water additions. I picked one up from Salvos for $6 a few months ago, as a bonus it works on my portable induction hob so I can use it next to the mash tun and don’t need to boil additions in the kitchen anymore.

I cheat with HW additions. I only roughly calculate what I need and take it from my mash liquor then borrow a bit extra from the sparge liquor. I then boil it all up add to the mash and use a fast read thermometer to check and stop when the desired temp is reached.

 

[kingdomplantae]

Ok, it’s all based on the standard mixing equation

Aa+Bb = Cc
Where A+B =C
AB and C are all a value in this case mass
ab and c are a condition.
To give a basic example if we had 5Kg of water at 25oC and we mixed that wit 2L of water at 95oC, plug it in and
5*25+2*95 = 7*c, 125+190=7*c rearrange to (125+190)/7=45oC
We would have 7kg of water at 45oC

We also need to know that malt has a thermal capacity of only 0.4 of water.

From this information we can work out the strike water equation, we use mass as all the units have to be the same ie kg, it’s handy that 1kg water is about 1L.

We modify the mixing equation to allow for the thermal capacity of malt and we get
0.4*Aa+Bb=Cc
Say we had 5kg of malt at ambient temperature say 19oC and we mixed it with 27kg of water at 70oC, we get.
(0.5*5*19)+(27*70)+=32c, 47.5+1890=32c, 1937.5/32=60.55oC

We can rearrange the equation to make it more useful in this case so it tells us how hot we need that 27kg of water to be to hit a selected temperature say we want to mash in at 62oC for a dry beer.
The rearrange equation would look like
Strike water temperature =[((0.4 mass grain)+mass water)*Target temp)]-(0.4mass mass*grain temp)/mass water.
Plugging in
[((0.4*5)+27)*62)-(0.4*5*19)]/27=[29*62-38]/27=65.2oC

OK so now we have a mash at 62oc and we want to add hot water (boiling) to raise the temperature to say 72oC
Remembering that the mash isn’t all water part of it is malt so we need to take its lower thermal capacity into account. what we do is calculate a new combined value called the Mash Heat Capacity (MHC)
It is
MHC=(0.4*Mass Grain)+Mass Water/Grain Mass+Water Mass (total mass)
For the above
MHC=(0.4*5)+27/5+27=0.90625

Nearly there
The following is yet another rearrangement of the above, using MHC keeps it a lot simpler than plugging in all the bits. Looks like -
Mass Boiling Water=(MHC*Mash Mass)*(Target Temp-Current Temp)/Boiling Water Temp-Target Temp.

Note that once taken off the heat, the water droops a couple of degrees very quickly, even pouring from a jug it would be better to use 95-98oC than 100, if going through a hose or transferring from an urn to a jug to the mash 90-95 is probably smarter. Always have a couple of litres more than you think you will need. Let’s plug in 95oc, if you measure carefully and keep records you can get a firm number for your process/system.

We have 35kg of mash at say 61oC we want to raise the temperature to 72oC, how much water at 95oC do we need to add?

=(0.9065*32)*(72-61)/95-77=29*11/23=13.9kg

And therein lies the problem with hot water additions, the hotter the mash and the larger the volume the more hot water you need. It can easily reach the stage where you need much more than you can practically use to get the steps you want.
With careful planning, mashing in thick (say~2.5:1 L:G) you can get two good steps without running out of volume or making the mash too thin.
It does require careful planning.
Mark

Great write up @MHB , Appreciate the time taken to summarise in a clear concise fashion!

I do see the volume dilemma, however you've provided a great understanding, and as suggested I think I can achieve my goal with a combination of approaches and good planning.

 

[kingdomplantae]

If you don't already have one and don’t mind spending a little more money you could get a cheap stock pot for hot water additions. I picked one up from Salvos for $6 a few months ago, as a bonus it works on my portable induction hob so I can use it next to the mash tun and don’t need to boil additions in the kitchen anymore.

I cheat with HW additions. I only roughly calculate what I need and take it from my mash liquor then borrow a bit extra from the sparge liquor. I then boil it all up add to the mash and use a fast read thermometer to check and stop when the desired temp is reached.

@S.E Mate great suggestion, and infact I've been on the look out for quite sometime, op shops I've never found decent sizes, I have a 7.5l already but am on the hunt for something around 20l.
Big w has some cheapies I've had my eye on.

I'm not scared of spending money here and there, just not in a position to drop hundreds of dollars at the moment.

I think next major purchase will be upgrading to conical fermenters, if I cannot nut out a sound DIY approach

 

[Hangover68]

@S.E Mate great suggestion, and infact I've been on the look out for quite sometime, op shops I've never found decent sizes, I have a 7.5l already but am on the hunt for something around 20l.
Big w has some cheapies I've had my eye on.

I'm not scared of spending money here and there, just not in a position to drop hundreds of dollars at the moment.

I think next major purchase will be upgrading to conical fermenters, if I cannot nut out a sound DIY approach

I would spend on a decent size brew kettle before a new fermenter, any fermenter will give the same result albeit more convenience .
You could put together a 35-40l electric kettle for under $100.

 

[yankinoz]

Mark-

Quoting "BIAB is not the easiest system to use if you want to do programmed infusion (heating what’s in the mash tun) as it requires either a pump recirculated wort or a stirred mash to work well. Both are a bit of a PITA when you have a bag in there, seen too many melted bags or bags wrapped around the stirrer.."

Doing Hochkurz mashes and mashouts, I've never found stirring hard at volumes of 15-25L, I may be the oldest person on this forum, and my mash efficiencies end up high. Never melted a bag, but I have a colander ring below it. Bag wrapped around the stirrer? Occasionally, but no great problem.

Dan

 

[MHB]

Hochkurz is a bit of a special case, it was primarily developed to avoid the need to do decoctions.

It is well suited to achieving the steps with hot water additions.

I was referring to using the element in a tun to achieve steps like most of the commercially available 1V systems. Having the malt in a pipe means the heated wort can be pumped through the grain bed from either top to bottom or bottom to top in a Braumeister. With a bag its virtually imposable to get even distribution of the heat as the wort will take the shortest path (usually out the sides) and you will often end up with bits of the grist at very different temperatures. Means in efect that you can have several different mashes going on at the same time.
Makes repeating the process difficult among other things.
In any system the application and distribution of heat is probably one of the most important design variables, if that is you aim to have controll of your process and achieve reasonable repeatability - make a good beer again...
Mark

Good basic info on Hochkurz scroll down a bit from the top.
M

 

[yankinoz]

Hochkurz is a bit of a special case, it was primarily developed to avoid the need to do decoctions.

It is well suited to achieving the steps with hot water additions.

I was referring to using the element in a tun to achieve steps like most of the commercially available 1V systems. Having the malt in a pipe means the heated wort can be pumped through the grain bed from either top to bottom or bottom to top in a Braumeister. With a bag its virtually imposable to get even distribution of the heat as the wort will take the shortest path (usually out the sides) and you will often end up with bits of the grist at very different temperatures. Means in efect that you can have several different mashes going on at the same time.
Makes repeating the process difficult among other things.
In any system the application and distribution of heat is probably one of the most important design variables, if that is you aim to have controll of your process and achieve reasonable repeatability - make a good beer again...
Mark

Good basic info on Hochkurz scroll down a bit from the top.
M

Thanks for the notes. FYI:

I use bottom heat, hence the colander ring. I've taken readings below the bag and colander, low in the bag and high in the bag. Within the bag it isn't hard to keep temperature variation < 1 degree. Below the ring it takes the use of a spatula inserted outside the bag and some hard stirring. A thin mash helps. I have found a temp of 73 there when the grist was at 71, but not for long.

Given that the bag probably precludes too intense bottom heat, the grist spends a significant amount of time at temps between 61 and 71. Mine usually takes 20-25 minutes

D