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General Category => All Grain Brewing => Topic started by: Caddywhompusbeer on September 02, 2011, 10:09:14 pm

Title: First AG, water volume questions
Post by: Caddywhompusbeer on September 02, 2011, 10:09:14 pm
I'm going to try my hand at AG this sunday and am a little unsure of my water volumes. I've looked at calculators that say I need about 8 gal after runoffs to start with but this seems a bit much to me. I'll be batch sparging and don't know my equipment loss & grain absorption yet. I do know my pickup tube leaves 1/8 a gal in the bottom of my keggle. I'll be making le petit orange ( http://www.northernbrewer.com/documentation/allgrain/AG-LePetiteOrange.pdf ) kit from NB. This is how I'm hoping it goes. If you see any issues or have other ideas please let me know.

I plan on using a mash thickness of 1.5 qt/lb, so at 8.5 lbs of grain I should start with 13 qts or 3.25 gal.

I'm assuming a water absorption of .1 gal/lb, being .85 gal in this case, so that should leave me with 2.4 gal for wort

Mashout with 1.1 gal to have a first runoff ending with 3.5 gal

Sparge with 2.5 gal to have 2nd runoff end at 6 gal

Assuming I lose 1 gal/hr in the boil I'll end up with 5 gal of beautiful wort. If need be I can boil a little longer or top off with some water.

Title: Re: First AG, water volume questions
Post by: Caddywhompusbeer on September 02, 2011, 11:22:15 pm
After thinking about it I'm not sure that my 55,000 btu burner will boil off 1 gal in an hour. I have a converted keg for a kettle. Would it be more like 1/2 gal?
Title: Re: First AG, water volume questions
Post by: morticaixavier on September 03, 2011, 12:18:14 am
I lose about 1 gallon an hour even when I am boiling on the electric stove. My kettle is maybe a little wider than the keggle but not much. I would stick with the 1 gallon/hour number for this first try. After than you will know.
Title: Re: First AG, water volume questions
Post by: euge on September 03, 2011, 12:29:04 am
You'll boil off more than you'd expect. It can be a considerable loss throughout the process. Then there's hop absorption to consider. And expansion and shrinkage. Doesn't hurt to have some extra hot or sterile water around. But, if you measure your water carefully and stick to your guns you'll fine tune it and figure out where your overages and losses are coming from.

Title: Re: First AG, water volume questions
Post by: jeffy on September 03, 2011, 07:47:55 am
Why not measure how much six gallons is in the kettle and mark it.  Sparge until it's a little higher than that to be safe.  I don't think I have ever calculated the amount of water, but I don't batch sparge, so I guess it is not as critical.  What I understand Denny does is run off the first batch, measure how much more wort is needed to top up the kettle and add that same amount of water to the mash.
Title: Re: First AG, water volume questions
Post by: Caddywhompusbeer on September 04, 2011, 07:27:08 pm
It went really well! Hit my target OG, only had one mishap which was remedied fairly quickly. My girlfriend thinks AG is more trouble than its worth, but she doesn't even drink my beer so who the hell cares lol. It did take me longer than it should have but the process is new to me, and I didn't start clean up until the wort was in the fermenter and yeast was pitched.

Very happy with the petit orangé and happy to have successfully brewed all grain.
Title: Re: First AG, water volume questions
Post by: Hokerer on September 04, 2011, 07:41:08 pm
Congratulations!  Things'll get smoother (and quicker) each subsequent brew you do as you get your processes down.
Title: Re: First AG, water volume questions
Post by: Caddywhompusbeer on September 05, 2011, 10:07:46 am
Thank you! I'm sure it will.
Title: Re: First AG, water volume questions
Post by: denny on September 05, 2011, 10:18:43 am
What I understand Denny does is run off the first batch, measure how much more wort is needed to top up the kettle and add that same amount of water to the mash.

Yeah, that's the pragmatic way to do it!  Although, after all the batches I've done, I've got a pretty good handle on volumes and can estimate really closely what I'll need for the sparge.  But I still always measure the mash runoff forst to make sure my calculations match reality.
Title: Re: First AG, water volume questions
Post by: Caddywhompusbeer on September 05, 2011, 03:39:13 pm
Denny, to find your grain absorption do you measure the first runoff after adding water for mashout then subtracting the mashout volume & calculating the amount absorbed? Or is there any negative impact to mash then runoff & measure then add it back to the cooler and then mash out?

Your website really helped me get through the process.
Title: Re: First AG, water volume questions
Post by: Hokerer on September 05, 2011, 07:08:18 pm
The beauty of the pragmatic method is that you don't care so much what the absorption is.  After your first runoff, you simply measure how much more you need to get your pre-boil volume, add that to the mash, and runoff the second time.  Done.

If you want to do calculations, you could measure your first runoff and simply subtract that amount from whatever total amount of water you had added to that point.  The only problem is that that doesn't directly tell you your absorption amount.  The calculated result will be the sum of the absorption and the dead-space in the tun.  The dead-space won't change from batch to batch but the absorption will.  In general, you're best off just using something between 0.10 and 0.12 gallons per pound of grain to calculate the absorption.
Title: Re: First AG, water volume questions
Post by: denny on September 06, 2011, 11:03:40 am
Denny, to find your grain absorption do you measure the first runoff after adding water for mashout then subtracting the mashout volume & calculating the amount absorbed?

You could certainly do that.  I should mention that I seldom do a mashout any more.  I've found that there isn't a whole lot of value in it.  The main reason I ever do (did) it was to approximately equalize the runoff volumes between mash and sparge runoffs.  These days, I simply increase my mash ratio to do that.  It's much easier and seems to have improved my efficiency slightly.

The beauty of the pragmatic method is that you don't care so much what the absorption is.  After your first runoff, you simply measure how much more you need to get your pre-boil volume, add that to the mash, and runoff the second time.  Done.

Absolutely!
Title: Re: First AG, water volume questions
Post by: Caddywhompusbeer on September 06, 2011, 02:03:23 pm
You guys are right. Looking back on the process it was a lot easier to "eyeball" it than to try to find out all the exact numbers. Think I'm gonna just go with a bigger mash ratio then adjust the sparge to make up the other half of the boil volume, not worry, have a homebrew, ect.

Thanks for the help.