Batch Sparging - Newbie Question

[Nztayls]

Okay,

So I am now all set for allgrain brewing. I have a mash tun - a converted beverage cooler with a bazooka screen, and a nice big brew kettle with a ball valve tap on it. Best of all, its solid stainless and works on my induction hop inside. I have done two brews already, both using batch sparging methods, and I am using beersmith v2 as my brewing software. 

I just have a couple of questions as far as the sparging goes. I know to take the first runnings off until they run clear, and then recirculate them through the top of the grain bed. My main question is, do I just keep refilling the mash tun, giving it a stir, then running it into the kettle until I get the desired amount of wort pre-boil (and does anyone know a rough rull of thumb as to how much is lost due to evaporation during a 60 and a 90 minute boil). Or is there a set amount of sparge water that should be run through the grains, and once thats it, then thats it? Following the suggested amounts of sparge water in beersmith has left me a little short of the volume I was expecting by the time I had cooled it and added it to the fermentor.

Any advice would be gladly accepted!

[oliver]

Tip: Figure out an accurate way of measuring the volume in your pot (e.g. mark out a stick). Next time you brew (or boil some water) - measure your boil off rate. Enter this value into your equipment profile in beersmith, you'll notice beersmith adds your boil off rate to the second sparge volume when you select a batch sparge mash profile. There's a limit to how much you can/want to sparge but I don't fully understand it, hopefully someone else can explain this to us :) You could always top up your kettle with water as long as you have enough sugars in there.

[Damon Colbert]

I'm going to be completely honest here.  I am a lazy brewer sometimes.  I haven't measured my evaporation rate.  I just collect what I need, do the boil, and add water back to the volume/gravity I need towards the end of the boil (or even in the fermentor - naughty!).

I should really get my act together and account for boil off and trub losses.

[oliver]

yeh fair enough, I'm sure that works too :) Actually trub losses are worth mentioning too, especially if you switch between malty beers and hoppy beers, havn't brewed enough hoppy beers to know what my trub loss is exactly, but it's worth factoring in some extra water/wort when doing hoppy beers I reckon.

[Damon Colbert]

Or for beers with a large amount of wheat malt, or unmalted grains (high protein content).  I have lost a lot of volume to hot break in my 50% wheat malt beers.

[oliver]

Ah sweet, didn't know that. How much extra volume would you factor in for say a 20L batch of 50% wheat?

[Damon Colbert]

Normally you sparge until you get to a runnings gravity of 1.016 (or start going above pH 6), or until you've hit your target pre-boil volume/gravity.  If you're a little short of volume, you can keep sparging.  But make sure you check the gravity of the runnings, and stop once it gets towards 1.016, as beyond that you will find pH starts to rise and you are likely to get increased tannin extraction.

I should note that you can correct for temperature when checking the gravity of a sparge.  A hotter sample will have a lower apparent viscosity.  Google 'Hydrometer correction' and you should find a few tools for that.  e.g. a gravity of 1.016 at 60C will have an actual gravity around 1.030 at 20C.

Just to check, you are recirculating the cloudy runnings each time you add in a new batch sparge and stir? 

As for your boil-off rate, olivers advice is pretty solid.  Evaporation is going to vary significantly depending on your kettle dimensions, burner, the vigor of your boil etc.  Best bet is to make some measurement for your system.

[Grant R Baker]

Batch sparge quantity of water is simply the required amount required to get you up to your pre-boil volume (since there is no absorbsion to worry about this bit is easy)... but of more importance is hitting your efficiency or pre-boil SG.

This bit has been the key for me to getting batch sparged brews up to spec... (volume is less important than desired target SG, OG and FG)  and a refractometer is a big help in judging where your pre-frementer brews are at.

Thus I Batch sparge for 30minutes all of my sparge water (unless ti won't fit in the mashtun).... and usually add all of my sparge water to the sweet wort... or up to the point the refractometer tells me to stop. If the  SG is a bit low then boil off some water before starting your count down.

Batch sparge runnings works the same as the first mash runnings. Run & return them until they are clear.

 

Evaporation: start at 10% per hour and adjust from there is subsequent brews. I'm at about 11% of my kettle for 90minutes but a larger brew maybe as little as 9.5%... take notes, they help over time.

Have a lookc at BrewMate... it is not a technical as BrewSmith but it might help you find the Sparge Water and Evapouration numbers you are looking for... and its free. Plug yer recipe into Brewmate then look at its BrewDay option... it might help.

[Alasdair]

Batch sparging is straightforward once you get the hang of it.

Once you know the pre-boil volume you need you can calculate how much water you need (taking into account how much the grain soaks up). The theory is that equal volumes of water from each "batch" of sparging is most efficient. For example, my pre boil gravity is 27l, so my first and second runnings are each 13.5L.

Give the mash a good stir before you start recirculating. And don't worry about PH and gravity of the runnings. Bacth sparging isn't efficient enough for these to be a problem. The runnings for lower gravity beers can be a bit grainy, but that's the case no matter how you sparge.

There's heaps of tips on-line about batch sparging. Just google Denny Conn.

And like the majority of brewing techniques, it doesn't matter so much how you do it, but you want to be consistent.

[Karl Hayes]

Hi.

I put some time lately into an Excel sheet with a few basic calculations, download it here and have a play around with it. I've found it works well for my brews. I think the trick is to get each batch - whether you have 2 or more - the same size.

[Karl Hayes]

And a +1 to Alasdair's comment about Denny Conn.

[paul m]

Just watched this vid on denny conn.

http://www.youtube.com/watch?v=ki61_HppGnY

real cool dude, explains it real well, stresses the idea of not stressing, keep it simple. great guru on homebrewing allgrain stuff!!

[Nztayls]

Thanks Karl, used it last night and it worked well.