partial mash...full boil...batch sparge amounts..

Homebrew Talk - Beer, Wine, Mead, & Cider Brewing Discussion Forum

Help Support Homebrew Talk - Beer, Wine, Mead, & Cider Brewing Discussion Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

TacoGuthrie

Well-Known Member
Joined
Jan 11, 2009
Messages
428
Reaction score
2
Location
P.R.
I've done a couple partial mashes but i've only used my 4 gal brewpot and therefore done 3.5 gal boils, topping up with water.

Batch sparge amounts have made sense for me mashing 4-6 lbs of grain and i've followed the recommendations i've read. Denny has a formula where your initial runoff volume should be half of your total boil volume. With my partial boils i've been able to come pretty close to that as i can usually collect about 1.5 gal for a 3.5 gal boil.

My schedule usually looks like this:

Mash with 8 qts.
1st runnings: 1-1.5 gal
Batch sparge: 1.5 gal
2nd Batch sparge: 1.5 gal


Now that i have a bigger pot there is no way i can collect 2.5-3G of runoff from just 6 lbs of grain. What would a sparge schedule look like for a partial mash into a 32 quart brew pot?
 
I don't know anything about the formula, but it sounds like it was designed for all grain brewers using a full boil. A partial mash, with a full boil will be different. As far as I understand you can sparge as much as you want keeping two things in mind:

1) don't sparge so much that the run off gravity is less then 1.010 as this can extract tannins from the grain.

2) You don't want to end up with more extra water then you can boil off.
 
Stick with the old schedule.

+1 on old schedule.

There's really no reason to change your schedule, unless you want to shoot for a higher efficiency. The enzymes have no way of knowing what your boil volume is going to be. :D If you want to get a little more out of your grains, you can do a thinner mash. (Some people use 2 qt / lb.) You can also use more sparge water. Just keep in mind the things I said above about over sparging.
 
i would top up with about 2 g in the fermenter in the old sched.

so i would just top up with water in my brew pot?

I think brian answered this question but is there a downside to just pulling that extra 1.5-2 gal of liquid from my grains instead of my water tap?
 
I like to use enough grain in my partial mash so that my first runnings and sparge get me right to my max boil volume. That way I top up with less at the end and I use less extract.
 
I can get up to about 4 gallons before the boil starts to get too sluggish on my electric stove. I use a 5-gallon Igloo for my partial mash tun.
 
I've got a 3G 'Bubba Keg' so have topped out at 6# of grain and 8 qt of water. Any more and it'll spill over the top of the cooler.

I can't wait to build a bigger mlt and jump up to ag but i'll keep this setup for stove top winter brewing.
 
That's why I went with the 5-gallon. This way my only limit on how much grain I can use in a partial mash is how much wort I can get to a boil. I just did a PM version of an Arrogant Bastard clone that used 7.5 lbs of grain. Still had to use 7lbs of LME though. :D
 
do you choose to stay with PM because of the jump in equipment (outside burner/ big pot)?
 
The reason you need to care is so that you don't over sparge. The easy rule of thumb is to not use more than 4 quarts of brewing water per pound of grain. That's strike + sparge.

Example. If you mash 4 pounds of grain and strike with 2 gallons (that's 2qts/lb). Given that, you want to limit your sparge to another 2 gallons. Your total preboil will be about 3.5 gallons.
 
Thanks, Bobby - that's a super helpful tip. Very easy to remember.

I'm assuming you can split up that 4 qts/lb any way you want, right? So, given your example, if I started with 4 lbs of grain and strike with 5 quarts (1.25qts/lb), then I could still be safe with sparging up to 11 quarts?

And if I wanted to add more water after that (to get closer to full boil amount, say), I could do that after removing the grains (I use DB's stovetop PM method)?

Just making sure. Thanks again for the tip.
 
Yeah, after that sparge amount, any new water should be added directly to the kettle. At that point the PH of the mash could be way the heck off and you don't want to extract tannins and other nasty flavors.
 
do you choose to stay with PM because of the jump in equipment (outside burner/ big pot)?

I'm currently an apartment brewer, so I have nowhere to brew outside for now. We're hoping to buy our first house later in the year, so I'll be making the leap sometime after that. :ban:
 

Latest posts

Back
Top