Importance of Sparge Water Cyphering?

I am probably missing an important point but, why can't I prepare 6 g. or so of sparge water (skip the arithmatic) and use what I need until I have my pre-boil amt. of wort? Since sparge water is supposed to be replacing the sweet wort does it matter if you just stop the lauter process when you have the desired amount in the boil pot. Thanks for your input.

Its less important in a fly sparge compared to batch sparge but ideally you get the best efficiency when your preboil volume is hit as the MLT is fully drained.

Thanks! I do currently fly sparge and can see the importance when batch sparging.

With a batch sparge, the sparge volume will be dependent on the amount of first runnings collected, which in turn is influenced on the size of the grain bill and the rate of absorption.

For instance: I calculate all my recipes based on 80% efficiency and 8 gallons pre-boil. With my kettle, I lose 2 gallons to evaporation over a 90 minute boil.

So, if I collect 2.5 gallons in first runnings, I need 5.5 gallons total sparge water to get me to that volume.

Am I correctly understanding your question?

Because as you sparge you are continuously diluting the wort.

We like to think of the clean water "pushing" the sugars out but it doesn;t really work that simply.

Point is, if you diregard water volumes and just sparge to pre-boil you will likely miss your target pre-boil gravity or post boil volume to gravity.

If you calculate your volumes to gravity targets then your chances of hitting the numbers improves.

That has been my experience at least.

Plus, not draining the draff in the MLT thoruroghly makes for a heavy summombitch to move to clean. Or, a lot of muck to vacuum out.

Yes Angler. But say, in your example, you mistakenly figured 6.5 g. for sparge and then seeing that your reaching your 8 g. and still have sparge water remaining you stop the lauter with the extra g. in the grain. Would that be a big problem or not since you were supposedly replacing "the good stuff" with sparge water anyway.

Gila, Thanks. My problem seems to be that when I try to figure the right amts. of mash and sparge water I always seem to come up short. Then I wonder if its better to add more sparge water or keep what I got and add plain water to the boil???

gman1 said:

Yes Angler. But say, in your example, you mistakenly figured 6.5 g. for sparge and then seeing that your reaching your 8 g. and still have sparge water remaining you stop the lauter with the extra g. in the grain. Would that be a big problem or not since you were supposedly replacing "the good stuff" with sparge water anyway.

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If I made an error like that, I'd collect the total volume and boil longer to compensate.

gman1 said:

Yes Angler. But say, in your example, you mistakenly figured 6.5 g. for sparge and then seeing that your reaching your 8 g. and still have sparge water remaining you stop the lauter with the extra g. in the grain. Would that be a big problem or not since you were supposedly replacing "the good stuff" with sparge water anyway.

Click to expand...

gman1 said:

Gila, Thanks. My problem seems to be that when I try to figure the right amts. of mash and sparge water I always seem to come up short. Then I wonder if its better to add more sparge water or keep what I got and add plain water to the boil???

Click to expand...

Have you dialed in boil off between seasons and verified system losses? How quickly are you sparging? sparge time is a HUGE factor on the fly.

Kinda sounds to me you are accounting for too much system loss and too much boil off, or sparging too quickly.

As to the volume question, I focus more on target gravity than I do volume. So, If I come up short after the boil and my grav is high, I will dilute to gravity target. If I come out low, I'll either eat it or boil to grav.

If my grav is spot on and I am low or high in volume, so be it I am done.

Aside from losses, and boil off, re-evaulate your system efficiencies and go from there.

It's like GilaMinumBeer says, you're not "replacing" wort with sparge water. While sparging does rinse the sugars in the runoff downward, it's not exactly like you're pushing a separate layer of sugary runoff through the outlet - every bit of water you add dilutes the sugars in solution. If you keep adding water, you'll leave behind several gallons of water that definitely contains some sugar in it.

How about try it the way you propose, and then measure the gravity of the liquid that doesn't make it in your brew kettle? Then you'll understand how much you're leaving behind.

Kanzimonson, Thanks to you and the others for the insight. I am in the Charlotte area as well and wonder if you belong to or know of any good Homebrew Assoc.?

Yeah, I'm a member of the Carolina Brewmasters though I'm not able to make it to a lot of meetings because they're on weeknights and I'm a baker so I gotta get to bed early!

But the meetings are great and people are always sharing their beers. If anything, join the club just so you can get a 15% discount at Alternative Beverage. And if you ever want to brew with me, I always welcome company. In fact, I'm brewing next weekend on Saturday and maybe Sunday as well.