Fly sparging and time

Howdy everyone. I've been a lurker here for awhile, but long time brewer. I have a question concerning fly sparging and how to extend the time of the sparge for better efficiency. I use a Phils sparger (whirlythingy) and generally about 4 gallons of sparge water, to eventually yield a 5 gallon batch after boil down (strike water is usually around 3-4 gallons depending on grain bill, so I generally have to boil off around 2 gallons). I adjust the rate of the water and the outflow of the mashtun absolutely as low as I can get it and keep a 2 inch layer of water on the grain bed. Doing that I am LUCKY to get a 15-20 minute sparge. How on earth are you guys getting the recommended 45 min- 1 hour times using these methods?? Thanks in advance for any advice.....

I use Phil's whirlythingy (that thing is so cool!) and Schmidling's EZ Masher in a 5 gallon kettle. Sparge time is 45 min to an hour, so perhaps it is the inner diameter of the tube? The fineness of the screen? I have never tried a false bottom so i don't know how that effects speed of run off.

trefoyl said:

I use Phil's whirlythingy (that thing is so cool!) and Schmidling's EZ Masher in a 5 gallon kettle. Sparge time is 45 min to an hour, so perhaps it is the inner diameter of the tube? The fineness of the screen? I have never tried a false bottom so i don't know how that effects speed of run off.

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Hmmm. I use the same set up, however, I use a 10 gallon gott cooler as the mash tun. I'm limited as far as tube diameter goes because it has to match the bottling bucket (my "hot liquor tank") and the phils sparger piece. I have slowed it down to where the whirlythingy barely even rotates and the hose coming off the mashtun is barely trickling wort into the kettle, but it still doesn't run anywhere near an hour.

I have a ball valve on my 10g cooler / mash tun AND one on my cooler / HLT. If you do the math, for example; you end up needing 1 quart every 3 minutes out of the mash tun to get 5g in an hour. I measure and time the first few cups/pints/quarts out of the mash tun to see if I'm in the ballpark. Then just watch the water on top of the grain and adjust as needed. With 2 inches of water on top of the grain, I'm not 100% certain the "whirlythingy" is really needed (but I use it just cuz it looks so cool).

I think the real key is the valves and being able to slow the flow down to a trickle.

Good luck.

I use a standard bottling bucket for a HLT, but I have another cooler I could install a ball valve on and see if that changes things. Part of the problem I have is that it takes a certain volume of water coming through to actuall spin the whirlythingy, so you can only slow it down so much. It may be that 4 gallons is just not enough sparge water.

What's your efficiency? Do you need better efficiency? Are you sure you're going to significantly increase your efficiency?

I fly sparge 14.5 gallons into the kettle in 30 min and my efficiency is ~88-90% (my system and technique allow for this). I used to sparge for longer and only got another percent or two of efficiency... not worth the wait.

well, I must admit that I haven't done a lot of calculating of my efficiency. I used brewsmith to calculate it on one of my batches and it was around 70%. I commonly get slightly smaller OGs than the recipe calls for--for example, if the recipe expects 1.070, I might get something like 1.067 (ballpark examples, obviously).

I would guess that I am commonly getting 65-70% efficiency.

knightbeer39 said:

I use a standard bottling bucket for a HLT, but I have another cooler I could install a ball valve on and see if that changes things. Part of the problem I have is that it takes a certain volume of water coming through to actuall spin the whirlythingy, so you can only slow it down so much. It may be that 4 gallons is just not enough sparge water.

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If you have some water on top of the grain bed, it doesn't matter at all if the whirlythingy is actually whirling.

-a.

You are adjusting your sparge time by what it takes to make the thing spin. You need to adjust the sparge flow at the ball valve (out from the mash tun) to take 45 minutes. Its worth it. Maybe only 1/2 hour for a 5 gallon batch.

I just lay the hose from the HLT on the grain bed. Its submerged by a couple of inches of water all the time.

Droot said:

You are adjusting your sparge time by what it takes to make the thing spin. You need to adjust the sparge flow at the ball valve (out from the mash tun) to take 45 minutes. Its worth it. Maybe only 1/2 hour for a 5 gallon batch.

I just lay the hose from the HLT on the grain bed. Its submerged by a couple of inches of water all the time.

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I've considered that, but that would mean that the level of water above the grain bed is going to get higher and higher, much more so than recommended 1 to 2 inches. I've always assumed that if the water level got too high it would have a negative effect on compacting the grain bed, but if that's false then there really is no issue with doing that.

I'm doing an olde ale tomorrow, so I'll give it a try!

ajf said:

If you have some water on top of the grain bed, it doesn't matter at all if the whirlythingy is actually whirling.

-a.

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That beckons the question then, what is the purpose of the whirlythingy? Are you not supposed to keep a layer of water above the grain bed when using that device??

I always assumed that the whirlygig was to evenly distribute small amounts of water without disturbing the grain bed. I do essentially the same thing as Droot (Buffalo represent!), except I fold up some aluminum foil and drip the water onto that (which is also how I recirculate while vorlaufing).

As for getting too much water: just turn down the HLT flow then! I have ball valves on my HLT and MLT and don't do any kind of calculation regarding flow. I let the HLT drip slowly until there's an inch or so of water, then I open my MLT slightly. I check periodically to make sure there's enough water: if there's too much, I turn down my HLT (or turn up my MLT). If there's too little, I do the opposite.

I don't even know how long sparging takes me. By this point in the day I'm probably listening to Live at Leeds, so I sit back with a pint of whatever I have on tap and listen to Roger Daltrey shorten 'thank you' to 'cue' after each song and maybe measure out my hops or something. (The one time I let it go too long I drained too much, my grainbed compacted and I got crap efficiency. Moral? Don't do that.)

knightbeer39 said:

I've considered that, but that would mean that the level of water above the grain bed is going to get higher and higher, much more so than recommended 1 to 2 inches. I've always assumed that if the water level got too high it would have a negative effect on compacting the grain bed, but if that's false then there really is no issue with doing that.

I'm doing an olde ale tomorrow, so I'll give it a try!

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I don't keep the sparge water running continuously. I set my ball valve on the outlet of the MLT to get the flowrate where I want it, then I gently add sparge water to my MLT until it's several inches above the grain bed, then I shut off the sparge water flow. Once the water gets to the point where it;s just above the grain bed, I add another batch of fresh sparge water. Depending on how much grain is in my MLT, I add sparge water 3-5 times in 45 minutes.

The height of the water above the grain bed has absolutely no effect on anything*. The only possible ill effect is that the water on the surface cools down a little bit over time, not enough to make a big difference though (especially in a cooler).

The key to fly sparging is that you are continuously contacting the grain with new, fresh water throughout the lauter. IMHO, it makes no difference how you get the fresh water there, as long as you don't disturb the grain bed.

I used to use the whirlythingy way back in the day, but no more. Add the water to the MLT however you want, as long as it's gentle.



*Disclaimer: At some point, i assume, hydrostatic pressure will have an negative effect, but not in any normal MLT. Also, hydrostatic pressure doesn't compact a grain bed, that comes from having to high a flow rate through the grain bed.

Sounds good. If I keep using the whirlythingy, I'll just need to resign myself to the fact that if I want to stretch the sparge time, I'm going to have to cut down the flow from the HLT to the point that it may not provide enough flow to spin the sparger. But since there is a layer of water on the grain bed anyway, sounds like that doesn't really matter. I'll give a go tomorrow and post here the results. I've never really had problems per se, I've just been curious how people are able to get these hour long sparges using this equipment....

I gave up on my whirlygig in short time after using it. It was too hard to guage the flow rate due to all the steam and it was a wonder the sparge water wasn;t ice cold by time it actually reached the grain bed.

Just keep in mind that the 1 to 2 inches of water over top is a minimum. The intent here is to force stratification and push the sugars down through the grain bed. Set your flow out of the MLT to a trickle and balance the HLT to that.

This has been a very useful discussion; thanks all!

I think I'll stick around this place for awhile

knightbeer39 said:

Sounds good. If I keep using the whirlythingy, I'll just need to resign myself to the fact that if I want to stretch the sparge time, I'm going to have to cut down the flow from the HLT to the point that it may not provide enough flow to spin the sparger.

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For what it's worth, this is exactly where I'm at. I was running through 5G of sparge water in 20 minutes just like you. It drove me nuts. So I slowed it down forcing myself to sparge for 60 min, and my whirly stopped whirling. I figured she was bent or broke and getting stuck. I considered buying a new one.

But now I think the whirlything is just a pipe dream. (Badoom-chuck.) It ain't designed to actually spin at the flow rate that we fly-spargers need to flow at.

So, these days I flow slow, at least 50 minutes, making sure I keep a couple inches over the grain, and every once in a while giving the whirly a poke, just to shift it a few degrees.

Judochop said:

For what it's worth, this is exactly where I'm at. I was running through 5G of sparge water in 20 minutes just like you. It drove me nuts. So I slowed it down forcing myself to sparge for 60 min, and my whirly stopped whirling. I figured she was bent or broke and getting stuck. I considered buying a new one.

But now I think the whirlything is just a pipe dream. (Badoom-chuck.) It ain't designed to actually spin at the flow rate that we fly-spargers need to flow at.

So, these days I flow slow, at least 50 minutes, making sure I keep a couple inches over the grain, and every once in a while giving the whirly a poke, just to shift it a few degrees.

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Well I used it this weekend on a Strong Ale and I managed to get a 60 minute sparge quite easily--I had to just cut the water off from the whirlthingy and let the MLT drain super slow. When the water level above the grain bed got a little shallow, I would just turn on the whirlythingy as slow as it can go and still rotate then cut it off again when I had a three or so inches of standing water. It seemed to work fine; I got around 80 percent efficiency so I can't complain.

The bottom line as far as I can see is that the whirlythingy is nice for not disturbing the grain bed INITIALLY as you are building the layer of water over the grain bed. Once you have that layer, it serves very little purpose other than just adding water to an already exisiting pool....