Fly Sparge - Predetermined volume or Boil Volume

[sicktght311]

Looking for some feedback from you Fly Spargers

When you fly sparge, assuming you mashed with a predetermined amount of strike water based on your usual mash thickness, which of the following do you do

1) Calculate your total Mash volume + Sparge Volume ahead of time, start your sparge at your typical slow sparge speed, and just keep the water flowing over the grain bed until you hit that sparge volume, stop your sparge, and drain your mash tun until you hit your target boil volume

or

2) Calculate your Mash volume, proceed with your mash as usual, and then sparge not paying attention to how much water you've sparged with, but instead just making sure to keep the sparge water flowing slowly at the same speed as the boil kettle runoff until you hit your target boil volume.

Typically i do number 1, but i'm wondering if you gain more efficiency by continuously running clean water over the grains, or if the sparge volume you precalculated is enough to fully properly extract, and once you hit that volume you just need to get that liquid out of the mash tun and into the boil kettle

 

[bracconiere]

i measure out a guesstimate for 10 gals of sparge water, i figure more is better, then sparge until my pot if full, and ready to boil....so i guess 2 . i get ~89% effeciency with a two step mash 150->162f....store bought malt my homemalt is all over the place anywhere from 70-85% usually 85%, depends how good a job i do sprouting it....

 

[Dustin_J]

I've done both, but prefer to calculate the necessary sparge water and add a bit extra (maybe .5 gal or so) just to make sure I have enough and don't start pumping air. With #2, it actually seems that you'd be potentially extracting a bit more, but diluting it substantially and leaving a lot more liquid behind so I'm not sure you'd really gain much, if anything.

 

[bracconiere]

"People who choose Bud and Coors over a microbrew are the same people that put catsup on their steak." - Some guy on the internet.

lol, but what about meatloaf?

 

[Dustin_J]

lol, but what about meatloaf?

I'd be offended if you didn't! BBQ sauce is an appropriate alternative, though.

 

[sicktght311]

I've done both, but prefer to calculate the necessary sparge water and add a bit extra (maybe .5 gal or so) just to make sure I have enough and don't start pumping air. With #2, it actually seems that you'd be potentially extracting a bit more, but diluting it substantially and leaving a lot more liquid behind so I'm not sure you'd really gain much, if anything.

This is one of those things that make my brain hurt. One side of my brain says "4.5 calculated gallons of sparge water over the grain bed, stop the flow when you hit 4.5 gallons, and let the mash drain to my boil volume because you're extracting all the sweet wort then and not just empty water", but my other side says "clean water is going over the top, and as long as its not channeling, its not going to be clean when it hits the bottom drain. Keep rinsing until you hit your boil volume because you'll be better rinsing the grains through the process. If you stop the flow of water, you're leaving some of the sugars attached tot he grains when the mash tun drains"

I think i'm gonna try number 2 on my next brew session of a recipe i've done before, and see if there's a noticeable difference in my efficiency. I'm struggling with getting over 75% brewhouse efficiency on my herms system. I've made excellent beer and adjusted my recipes to account for it, and its consistently the same 70-75% efficiency every time depending on the grains i'm using, but i'd love to bump that up to get more bang for my buck out of my grains. I've tried narrowing the gap on my mill only to get constant stuck mashes even with rice hulls and no noticeable increase in efficiency. I've tried different mash thicknesses and sparge amounts. Etc Etc just trying to narrow down where i'm going wrong

 

[bracconiere]

This is one of those things that make my brain hurt.

that's why i like my system, i just figure i sparge with final volume after boil.....works for 10 gal batches, and 5...i've always assumed i'm boiling off the strike water that didn't get absorbed by the malt.....

i believe sugar sinks? sorta, so fresh water at the top just pushes it down the tun.....out of curiosity, i'm going to make a syrup, and pour it into water....well, it just dissolved, lol. i think it works different with the mash though....

(i should mention, i just use a pot, and colander for my sparge, and it usually does drop below the 2" on top rule, usually about 2-3 inches below the surface. and i do drain completly before starting the sparge, kinda like a hybrid batch/fly thing, where i batch sparge, but do the second runnings as a fly sparge)

 

[bracconiere]

Etc Etc just trying to narrow down where i'm going wrong

i remember that feeling, back when i was using boiling water, and running the ball valve full open, and getting 65%....lol i know the struggle!

 

[Bobby_M]

In fly sparging, you don't really want to run the grainbed dry (which would happen if you calculated the exact amount of sparge water (like you would for batch sparging). The intent is to keep the entire grain bed as fluid as it was when you were resting the mash. So, on the technically optimal side you'd continue sparging, maintaining 2" of water on top of the grain until your preboil volume is reached. I typically compromise just a little bit and stop adding sparge water when I'm 2 gallons short of my PBV. The exposes the top of the grainbed, but just barely. Running it dry causes grain bed collapse which encourages channeling and lowered efficiency. You'll find 100 people who do it every variation you can imagine and claim amazing efficiencies but we are talking about theoretical ideals.

 

[bracconiere]

You'll find 100 people who do it every variation you can imagine and claim amazing efficiencies

agreed, and not to mention the people that scold people about 'different' effeciencies.....lol, i know i can get a 10 gal batch with a ~1.063 gravity with 20lbs of malt...

 

[eric19312]

In fly sparging, you don't really want to run the grainbed dry (which would happen if you calculated the exact amount of sparge water (like you would for batch sparging). The intent is to keep the entire grain bed as fluid as it was when you were resting the mash. So, on the technically optimal side you'd continue sparging, maintaining 2" of water on top of the grain until your preboil volume is reached. I typically compromise just a little bit and stop adding sparge water when I'm 2 gallons short of my PBV. The exposes the top of the grainbed, but just barely. Running it dry causes grain bed collapse which encourages channeling and lowered efficiency. You'll find 100 people who do it every variation you can imagine and claim amazing efficiencies but we are talking about theoretical ideals.

That’s interesting

I run the grain bed dry as it makes cleanup easy. Also salt calculations if I’m salting my sparge water.

But my efficiencies aren’t anything to brag about...usually about 75% brewhouse. Might be worth trying.

One question...my grain bed never seems to set. Lots of floating grain through entire recirc mash. Is this a problem?

 

[RedwoodMonkey]

Just chiming in that I'm super curious about people's opinions on this. I was doing specific volume calculations and fly sparring till it was out of water, running the grain bed dry. The last beer I tried the constant sparge without calculating the water, and just stopped when I had the right pre-boil volume. This ended up making my pre-boil gravity a bit weaker than my last brew...but the last one was also a bit short on the amount of water I calculated.

 

[Bobby_M]

Just chiming in that I'm super curious about people's opinions on this. I was doing specific volume calculations and fly sparring till it was out of water, running the grain bed dry. The last beer I tried the constant sparge without calculating the water, and just stopped when I had the right pre-boil volume. This ended up making my pre-boil gravity a bit weaker than my last brew...but the last one was also a bit short on the amount of water I calculated.

There are a lot of other mechanics at play. What kind of false bottom do you have? Does it cover the whole diameter of the tun? How many gallons is your preboil? How long did the sparge take?

 

[RedwoodMonkey]

There are a lot of other mechanics at play. What kind of false bottom do you have? Does it cover the whole diameter of the tun? How many gallons is your preboil? How long did the sparge take?

Yeah, I know there are a ton of variables! I've got a ~12+ year old kettle kit from MoreBeer (Beer Beer Beer back then) that I bought used from someone a few years ago. It's got a regular grate-style false bottom; it covers the whole diameter and sits a few inches above the bottom (and above the outlet), but it doesn't have any tight seals.

I was also playing with doing a HERMs recirculation at the time, when I normally don't do it...so that could easily account for variability in temperatures and my lower-gravity level.

I'm still curious to hear other people's thoughts on sparging (calculating the volume and draining the mash tun dry, or constant sparging till you have the pre-boil volume -- or, another way, is to constant sparge until you hit the desired pre-boil gravity -- I could care less exactly how much beer I get, but I want consistent beer).

 

[day_trippr]

I'm wondering if there's any difference in extract efficiency between a decent batch sparge and running a "fly sparge" dry. My suspicion is you might as well do the former and avoid the down-side of channeling with the latter...

Cheers!

 

[catalanotte]

I have seen 75-85% with higher efficiencies fly sparging. Always start with extra sparge water and sparge to target preboil SG, regardless of volume. Sometime I have extra, sometimes I’m short, but always get the brew I want based on OG.

 

[doug293cz]

I'm wondering if there's any difference in extract efficiency between a decent batch sparge and running a "fly sparge" dry. My suspicion is you might as well do the former and avoid the down-side of channeling with the latter...

Cheers!

The best data I have seen gives a "perfect" fly sparge about 2 - 3 percentage points higher lauter efficiency than an optimal 3X batch sparge. Getting that result requires excellent technique. I have seen no data comparing "mash tun left full" and "mash tun drained" fly sparging.

Brew on

 

[Dog House Brew]

In fly sparging, you don't really want to run the grainbed dry (which would happen if you calculated the exact amount of sparge water (like you would for batch sparging). The intent is to keep the entire grain bed as fluid as it was when you were resting the mash. So, on the technically optimal side you'd continue sparging, maintaining 2" of water on top of the grain until your preboil volume is reached. I typically compromise just a little bit and stop adding sparge water when I'm 2 gallons short of my PBV. The exposes the top of the grainbed, but just barely. Running it dry causes grain bed collapse which encourages channeling and lowered efficiency. You'll find 100 people who do it every variation you can imagine and claim amazing efficiencies but we are talking about theoretical ideals.

This is what I do^^^^

 

[kevin58]

I vote for sparge until you hit your pre boil volume. I mash with a pre determined amount of water but then fill my HLT with more than I need for the fly sparge. The left over hot water in the HLT is used for clean up later.

 

[sicktght311]

I've got a new mash tun on order, so i'll be switching my fly sparging to "Sparge until i hit boil". Especially since my new tun has a larger deadspace under the raised false bottom, which means i'll be mashing in with more water than my previous tun to keep the water to grist ratio the same, which also means my old method would leave me with less "calculated sparge water" had i stuck to my old way of doing things.

Woudlnt it be nice to brew this batch and all of a sudden get 85% efficiency?