Question about fly sparging

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maltMonkey

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I'm gearing up to attempt my first AG--planning a single temperature infusion mash with a fly sparge. From what I've read, you want to continue to collect wort until the SG in the MLT is 1.008-1.010.

So what do you do if your SG is high or low? If you've collected your 6 gallons or whatever and the SG is still high, do you keep collecting and plan a longer boil? And if you're a gallon short but you're lower than 1.008 do you keep collecting or just stop and add water to the boil?
 
The first few times you do this you'll be discovering your efficiency baseline. You'll formulate your recipe with say 70% efficiency and then see what you end up with. If your gravity is low, you can make up with a little DME. Next time, set your efficiency to whatever it WAS on the last batch. Now you'll come in closer.

Are you sure you have the equipment suited for fly sparging? By the way, sparge until you have a reasonable preboil volume that will not require a 3 hour boil. Figure on somewhere between 1-1.5 gallons of boil off per hour. If you want 5 gallons in the fermenter, sparge until you have 6.75 gallons and boil for 70 minutes or so.
 
Bobby_M said:
By the way, sparge until you have a reasonable preboil volume that will not require a 3 hour boil. Figure on somewhere between 1-1.5 gallons of boil off per hour. If you want 5 gallons in the fermenter, sparge until you have 6.75 gallons and boil for 70 minutes or so.


+1

I also wouldn't concern yourself with gravity of the runnings right now. Sparge to your preboil volume.

I would take a gravity when you reach the preboil volume to see if you could have sparged more (or less) to establish the baseline efficiency that Bobby mentioned.
 
Bobby_M said:
The first few times you do this you'll be discovering your efficiency baseline. You'll formulate your recipe with say 70% efficiency and then see what you end up with. If your gravity is low, you can make up with a little DME. Next time, set your efficiency to whatever it WAS on the last batch. Now you'll come in closer.

OK, that makes sense....so basically if I use the same equipment and technique every time then my efficiency should always be about the same regardless of how large or small the grain bill is? Or will it be different for different grain bill sizes?

Bobby_M said:
Are you sure you have the equipment suited for fly sparging?

I believe so....there isn't much more equipment required outside of a sparge arm, is there?

What I have now is a 30qt hot liquor tank (I need a bigger one soon) that feeds via gravity through a sparge arm into my 60qt cooler MLT. I should be OK, right?

Bobby_M said:
By the way, sparge until you have a reasonable preboil volume that will not require a 3 hour boil. Figure on somewhere between 1-1.5 gallons of boil off per hour. If you want 5 gallons in the fermenter, sparge until you have 6.75 gallons and boil for 70 minutes or so.
That raises another question: if you underplan for boil off evaporation and end up with say 4.5 gallons can you just make up the difference with some more water?

Thanks a bunch...I really appreciate the help.
 
Efficiency is mostly constant given everything is done exactly the same. Same relative temps, process, etc. I've found, along with others that as your intended OG goes up, efficiency does go down. I don't know what the ratio is, but it's observable.

Right, fly sparging requires some kind of sprinkling device but I'm more concerned with the extraction device. False bottom, manifold or stainless braid in there? Batch sparging might take a few variables away for the first time.

Yup, if you boiloff too much, a little top off water at the very end of the boil would be fine. You could add it to the fermenter, but a short ride in the kettle at the end of the boil ensures sanitation (if you have a way of measuring volume in the kettle).
 
Bobby_M -- As far as the extraction device I have a 2 foot stainless braid that runs the length of the cooler.

I initially starting planning for fly sparging because ultimately that's how I wanted to brew all my beers, and I figured I might as well start with that route even if I messed up the first couple batches. I'm cautiously optimistic about the upcoming "virgin" brew, but I'm brewing some relatively small pale ales until I get all my techniques & efficiencies figured out.
 
The only problem with the braid is that you can't be sure to avoid channeling. When the sparge water has an easy path, which I would imagine would be a quick turn towards the centerline just above the braid, you tend to miss a lot of sugar in the lower portion of the cooler furthest away from the braid. I'm not saying you'll absolutely have problems but I would guess at about 60% efficiency.
 
hmmmm.....I hadn't thought of that. I guess if I get a low efficiency I could always add a second or 3rd braid and weave it around the cooler.....

If you're thinking 60% I need to adjust my grain bill, as I think beerTools defaults to 72%. Thanks for the heads up!
 
I'm just starting out AG as well and I'm planning on batch sparging the first few times to get the hang of it, that way I can use the mash tun I just built (with a single stainless steel braid). If i want to go to fly sparging I'll need to make a manifold, probably out of rigid 1/2" copper I'd imagine.
 
Bobby_M said:
The only problem with the braid is that you can't be sure to avoid channeling. When the sparge water has an easy path, which I would imagine would be a quick turn towards the centerline just above the braid, you tend to miss a lot of sugar in the lower portion of the cooler furthest away from the braid. I'm not saying you'll absolutely have problems but I would guess at about 60% efficiency.


so does batch sparging lead to less channeling issues then? i have just switched from a false bottom to a stainless braid since upgrading to a 10 gal setup using a keg as my mash tun and i got a pretty low OG (though this could also be due to the mash being too hot (72 C)).
 
Batch spargers don't even need the word channeling in their vocabulary. You dump sparge water in, stir like crazy, then drain the tun (after a quick recirculation of course). The reason there is no channeling is because you forcefully get the water into contact with all available sugar through stirring. The key to good efficiency with batch sparging is to run out the sweet wort fully prior to the first sparge and break up the sparge volume into two equal batches. IOW, you run wort out of the tun 3 separate times.

With fly sparging, you're hoping all the water finds its way to the sugar on its way down to the bottom of the tun.
 
A lot of good advice from Bobby (who is a batch sparger).

I usually fly sparge, and usually take about 90 minutes to finish the sparge.
With a small grain bill (O.G. below 1.050), I would oversparge with a 90 minute sparge, so I cut it down to about 60 minutes.
With a large grain bill (O.G. over 170), I need to collect extra wort to get the gravity of the last runnings down to 1.010 with a 90 minute sparge. In that case, I usually stop the sparge when I have collected enough wort, and it doesn't hurt my efficiency. I still seem to get 85%
For normal brews (O.G. from 1.055 - 1.060), I sparge to collect 6.75g, and always end up with the final runnings at about 1.010. This is so predictable that I hardly ever bother to measure it.
But I use a round Rubbermaid cooler with a false bottom. This gives me a much greater grain depth than you will get, the sparge arm delivers water evenly over the entire grain area, and the false bottom allows the wort to be collected across the full area. With a rectangular cooler, you will have a much shallower grain bed. The braid only allows collection from a small area close to the braid, and the sparge arm probably won't deliver sparge water over the entire surface.
It is my belief (but I cannot say for sure) that these factors will contribute to very poor efficiency with a fly sparge.
The good news is, that the rectangular cooler and braid are excellent for batch sparging, and you could save a whole bunch of time while getting much better efficiency.

-a.
 
You guys are bringing up a lot of things I hadn't considered yet.....It sounds like I probably need to install some sort of false bottom if I want to fly sparge....
 
Yes, false bottoms are the preferred method for a fly sparge lauter. There was a great write up about mash tun design and efficiency by John Palmer in a recent BYO. I'm sure you could find it online. There are lots of things to consider in MLT design. The first is how you are going to sparge. From that you can design the best system around which technique you are going to employ.
 
Bottom line is if you plan to fly sparge you'll either have to

1. Create a rectangular manifold to cover more area on the bottom of that cooler.
2. Buy a 10 gallon round cooler with a false bottom.

Given you already have the rectangular and braid, I implore you to batch sparge on your first all grain. If you hate it afterwards, play around with fly. I assure you it will not feel any less like "real" brewing.

Check out Denny's page on batch sparging. Watch my batch sparge videos. Mind your temps. Let 'er rip.
 
+1 for Bobby's tips. I would say that if you have a rectangular cooler and have small grain depth you should not fly sparge at all due to channeling. If it was a bigger depth then it would be OK if you made the proper design to cover the whole grain bed with sparge water. I personally batch sparge all the time in a round Rubbermaid cooler and always sparge two times after draining the tun.
 
Well, I just got my 55lb bag of Maris Otter a week early, I'm ready to go, and I don't have time to try to get a false bottom together for this thing....

So I'm either going to try to quickly learn how to do a batch sparge, or up my grain bill and suffer through some inefficiencies while fly sparging....

.....either way, I'm doing my first AG tomorrow!
 
I read somewhere (can't remember where) that if I fly sparge I should allow the water in the mlt to fill up about 2 inchs above the grain bed. Then let about 1 qt a minute drain out the bottom via braid/false bottom/manifold as I add 1 qt onto the top via a sparge arm.
1. is allowing the water to fill above the grain bed an issue?
2. would this allow more water to reach all the sugars?
3. any better techniques I should be using?

I have a 10 gallon round home depot cooler with a 12 in SS braid.
 
I wouldn't try fly sparging with a braid. You will get channeling resulting in poor efficiency. You could get better efficiency with a batch sparge in less time, and with fewer potential problems.
Check out http://www.howtobrew.com/appendices/appendixD-1.html for some good information on manifold designs for fly sparging. If you really want to fly sparge, a false bottom gives you the best results in a round cooler.

-a.
 
My first AG I used the fly sparge method mostly because I didn't know any other way.
15.5 keggle with AIB false bottom, it sits almost 4" off the bottom and was wondering if this distance makes any difference at all.

OG was 1.052 FG 1.010 so I was happy at my first attempt. Dont want to jack this thread but it is a sparging question that might apply.

I fly sparged at 170f for 60 minutes and never touched the grain bed and kept the water about 1" above grain. Used a march pump, worked very well for consistency, gravity does not stay consistent throught sparging so you might want to setup a pump system if you want to fly sparge.
 
Fly sparging works fine as a gravity feed process. Just go slow so you get an even flush. Slowness helps with chanelling too, but you want a proper maifold or false bottom for a clean rinse.

I don't often hear many batch spargers complain about their equipment's shortcomings though, hmm.
 
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