I am new to AG brewing after 6 extract and 2 partial mash and I have a question about volume size from mash to the boil. The beer i brewed had a 12 lb grain bill. i had just about 3.75 gal of water in the mash tun + 1.5 gal for Mash out + about 6 gal of sparge water. The end result was about 8 gallons into my boil, for what was supposed to be a 5 gallon batch. after boil i was at about 7.5 gallons and couldnt get all of the liquid into my fermenter. I cant help but think i am missing a step or had something wrong in my process. any insight would be appreciated.
Cut back on your sparge water. You want to pick a water/grist ratio that works for you. Many use 1.25 - 1.5qt/lb. I prefer a little thinner mash at 1.5 - 2.0qt/lb. Figure out how much you’ll get from your first runnings and then get the balance you need from you sparge runnings. If you only boiled off 1/2gal in an hour (seems low), you want to start with 1/2 gal more wort than what you want for your post boil volume to be.
Example (rough numbers to illustrate):
5.5 gal post boil desired.
1/2 gal/hr boil off.
Need 6 gal from combined runnings.
Mash yields 3.75gal.
Sparge with 2.25gal to equal 6 gallons combined.
I’ll add I try to shoot for close to equal runnings or at least within about 1 gallon of each other at the advice of Denny. So with the numbers I posted above, I’d probably cut back on the initial mash water to get closer to 3 gallons from the first runnings and closer to 3 gallons from the sparge. This doesn’t need to be exactly 50/50. I’m usually more like 60% volume from my mash and 40% from the sparge.
You’ll need to work backwards…
You now have a general idea that you’ll boil off half a gallon, so shoot for 5.5 or 6 gallons in your kettle.
Conventional wisdom aims for equal runnings, so plan on half of that (3 gallons) to come out of sparge. Mash with what’s left, and add some for grain absorption.
Thanks for the quick replies. I left my lid on during most of the boil, which i believe is what contributed to the lower boil off amount.
Also, when fly sparging, do you begin to sparge immediately after the vorlauf or will you run some out of the mash tun until you have just an inch or so above the grain bed?
Definately don’t use a lid when boiling. You don’t want to induce any dms. I usually start with about 7 gallons to end up with about 5.5. it also depends on how vigorous your boil is. Is your boil a rolling type or just a simmer.
[quote=“jra173”]Thanks for the quick replies. I left my lid on during most of the boil, which i believe is what contributed to the lower boil off amount.
Also, when fly sparging, do you begin to sparge immediately after the vorlauf or will you run some out of the mash tun until you have just an inch or so above the grain bed?[/quote]
If you’re fly sparging, the answers you got may not be applicable. They all look like batch sparge ideas. But you should be batch sparging, anyway! 
[quote=“jra173”]Thanks for the quick replies. I left my lid on during most of the boil, which i believe is what contributed to the lower boil off amount.
Also, when fly sparging, do you begin to sparge immediately after the vorlauf or will you run some out of the mash tun until you have just an inch or so above the grain bed?[/quote]
Once the boil starts you will want to boil w/ as much of the lid off as possible. During the boil certain undesirable compounds are boiled off but w/ the lid on they cannot exit and will drip back in from under the lid.
When fly sparging once you are done vorlaufing keep the drain going into your pot. Then start the laughter water to the rate you need so you maintain about an inch above the grain bed.
Stop draining when you reach the amount you need for your boil. Just because you have more that could be drained from the mash doesn’t mean you need to keep going. If you go to long it’s possible to extract tannins as the mash will want to climb in pH the more you extract from it.
Edited for my lack of comprehension skills today. 
[quote=“dsiets”][quote=“jra173”]Thanks for the quick replies. I left my lid on during most of the boil, which i believe is what contributed to the lower boil off amount.
Also, when fly sparging, do you begin to sparge immediately after the vorlauf or will you run some out of the mash tun until you have just an inch or so above the grain bed?[/quote]
Once the boil starts you will want to boil w/ as much of the lid off as possible. During the boil certain undesirable compounds are boiled off but w/ the lid on they cannot exit and will drip back in from under the lid.
When fly sparging once you are done vorlaufing keep the drain going into your pot. Then start the laughter water to the rate you need so you maintain about an inch above the grain bed.
Stop draining when you reach the amount you need for your boil. Just because you have more that could be drained from the mash doesn’t mean you need to keep going. If you go to long it’s possible to extract tannins as the mash will want to climb in pH the more you extract from it.[/quote]
when fly sparging, do you follow the guide of 2qts of water per lb of grain? if so, what do you do with the extra liquid?
You leave it behind once you get your boil volume.
Sure you wouldn’t rather batch sparge? I think you’d find it faster and easier, with results at least equal to fly sparging.
You leave it behind once you get your boil volume.
Sure you wouldn’t rather batch sparge? I think you’d find it faster and easier, with results at least equal to fly sparging.[/quote]
I have thought about it. I want to fly a few times, get that process down and then batch a few times…and pick a winner. so far i have enjoyed the learning part of the process almost as much as the consuming portion.
If batching, i would just dump into mash immediately after vorlaufing with the valve on my mash tun staying open…correct?
[quote=“jra173”]I have thought about it. I want to fly a few times, get that process down and then batch a few times…and pick a winner. so far i have enjoyed the learning part of the process almost as much as the consuming portion.
If batching, i would just dump into mash immediately after vorlaufing with the valve on my mash tun staying open…correct?[/quote]
If you fly sparge first, I can pretty much guarantee you’ll LOVE batch sparging! Keep in mind that batch sparging takes less equipment, so you might want to try that first, then buy the extra stuff you need if you decide to try fly sparging.
No, you run off your mash tun, then close the valve. Dump in all your sparge water at once, stir thoroughly, then vorlauf and runoff again. The 2 vorlaufs are no big deal becasue with my system the wort clears so quickly. You can read about it and see pics at dennybrew.com
[quote=“jra173”]
when fly sparging, do you follow the guide of 2qts of water per lb of grain? if so, what do you do with the extra liquid?[/quote]
When I was fly sparging, if I recall, I was doing 1.25 qts/lb grain for the mash conversion.
The extra liquid leftover was just to keep the grain “floating” to avoid channeling. If you have to/want you can stop your sparge water
and let the 1’’ of water on top disappear if you are near your target volume and can predict how much you have left. But at this point the gravity of your run-off is
going to be pretty low and you don’t want to push it lower or your pH higher.
If you are going to explore fly-sparging for a bit be sure to check the gravity of your final runnings. You generally want to stop before it gets below 1.010.
