Low Fly Sparging Efficiency Gain

I brewed my first batch last weekend after switching from batch sparging to fly sparging and my efficiency only went up about 3-5%. I build my manifold, based mostly on the instructions from How to Brew. After I built it, I tested it with some tap water and food coloring to see if I would get any channeling, etc. The food coloring slowly settled to the bottom as I drained and seemed to spread evenly throughout the MLT.

Also, when I lautered I kept the flow rate very slow. I didnt time it exact, but I was very close to 1 qt/min and took me around 45-60 min to drain 6.5 gallons from the tun.

I expected to see more of an increase in my efficiency, closer to 10%, and thought of a couple things that could have effected my efficiency.

First, I didnt do a mash out. I know not everyone does them, but they can help with sugar extraction and flow. I used 1.5qts/lb of mash water and didnt have any problems with flow rate. However, even with my sparge water at ~185, my mash temperature never rose above about 150 during the sparge and lauter. Could I hvae lost some efficiency due to the temps by not improving the viscosity and rinsing the sugars enough?

Also, there was one part when I wasnt paying attention to my sparge and the water level dropped just below the top of the grain bed. B/c of my sparge setup, its difficult to dial in the exact flow rate of sparge water to outflow of wort to just keep it open. I know you are supposed to maintain about 1" of water above the grain bed, and cant imagine that jsut a couple min of not having enough would effect this.

Oh, and BTW, I am using a CPVC manifold with slits cut in the bottom 1/4" apart and the deadspace in my MLT is minimal, probably 1-2 cups, max


Any thoughts, ideas, suggestions??

/bump........ Anyone?

What was your efficiency before? If it was already fairly high you prob won't gain all that much from fly sparging. Sounds like you did everything OK. The level dropping below the top of the grain probably didn't affect it, but it's possible.

I would do a mash out though. Mainly to set the fermentability of the wort than for any efficiency gains. 60 minutes lautering/sparging (plus however long it takes to get the wort >175-ish) is a good bit of extra time for the enzymes to be working.

SpanishCastleAle said:

What was your efficiency before? If it was already fairly high you prob won't gain all that much from fly sparging. Sounds like you did everything OK. The level dropping below the top of the grain probably didn't affect it, but it's possible.

I would do a mash out though. Mainly to set the fermentability of the wort than for any efficiency gains. 60 minutes lautering/sparging (plus however long it takes to get the wort >175-ish) is a good bit of extra time for the enzymes to be working.

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I was getting 70-72% with dark beers and ~75% with lighter beers. I hit 75% while making the porter.

Yea, that was my thought on the mash out. I decided not to do one so I would have more sparge water to rinse the grains, but I think I'll go back to doing one. I have also done thin decoctions for mashout (with not much success) and think I will go back to trying those.

Thanks!

Decoction mash out is a great idea. I recently switched to new brew kettle and because the dead space makes the mash seem thicker for a given water:grain ratio I have to use more water during the mash. That sort of made a decoction mash-out a necessity if I'm doing multi-step infusions, otherwise I just don't have enough sparge water.

Different efficiencies by beer color suggests a potential mash pH issue. Have you looked into that? Have you ever tested for literal mash/conversion efficiencies by taking the gravity of the mash liquor before runoff?

You also might fine an efficiency gain by mashing a little thicker ~1.25 because it will flush more higher gravity wort when the sparge first starts. This assumes you're not having conversion problems.

With all that said though, 75% efficiency is just dandy.

Bobby_M said:

Different efficiencies by beer color suggests a potential mash pH issue. Have you looked into that? Have you ever tested for literal mash/conversion efficiencies by taking the gravity of the mash liquor before runoff?

You also might fine an efficiency gain by mashing a little thicker ~1.25 because it will flush more higher gravity wort when the sparge first starts. This assumes you're not having conversion problems.

With all that said though, 75% efficiency is just dandy.

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Yea, I have been very happy with 75% batch sparging. I was hoping to see an increase, but if I dont, thats fine....

Im not sure if it is a pH issues, I have just started doing water adjustments and getting my beer with the correct residual alkalinity for the style.

I usually mash at 1.25, but decided to do 1.5 for this brew since mash and sparge water volumes would be equal. I have always had better efficiency with 1.25....

I've been fly sparging for 17 years. For many of those years, I got 75% efficiency. Then I started doing a mash out, and my efficiency instantly increased to 85%.
At about the same time that I started doing a mash out, I tried batch sparging for about 10 brews. With the batch sparge (and an OG of about 1.050), my efficiency dropped to 80% About 2 years ago, I switched from a 5g MLT to 10g, and my fly sparge efficiency dropped 5% to 80%. I tried one batch sparge with the 10g MLT, and got 78% efficiency. Since I switched to the 10g MLT, my fly sparge efficiency has gradually risen back to 85%..
So what did I conclude from this?
1. When fly sparging, a mash out can make a big difference in efficiency. (When I started doing the mash out, the grain bed temperature during the sparge increased from about 155F to the high 160's, and I believe that this was primarily responsible for the 10% increase in efficiency.)
2. Familiarity with the process/equipment improves efficiency. That's the only explanation I can think of that would explain why my efficiency with the 10g MLT dropped to 80%, and then increased gradually back to 85% with no changes in equipment or procedures.

-a.

Sounds like a mash out it is! I decided to skip it (which I have never done before) b/c in How to Brew, Palmer says he skips it with no issues. I guess since my temps dropped so much, the sugars couldnt flow well.

Thanks for the info!

chode720 said:

Sounds like a mash out it is! I decided to skip it (which I have never done before) b/c in How to Brew, Palmer says he skips it with no issues. I guess since my temps dropped so much, the sugars couldnt flow well.

Thanks for the info!

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I think Palmers adds a caveat to that statement by saying that a mashout is usually not needed if you mash relatively thin (1.5-2 qt/lb). You were at the low end there. Also, a mashout is much less needed (as in, usually not at all) when batch sparging vs. fly sparging.

SpanishCastleAle said:

I think Palmers adds a caveat to that statement by saying that a mashout is usually not needed if you mash relatively thin (1.5-2 qt/lb). You were at the low end there. Also, a mashout is much less needed (as in, usually not at all) when batch sparging vs. fly sparging.

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I agree with the no mash out when batch sparging
As for not needing a mash-out with a thin mash, I must admit that I usually mash at 1 qt / lb, so you may not get the same benefits from a mash-out as I do.

-a.

So, I just wanted to give an update on this post.....

I just brewed today and did a mash out this time. With this, my efficiency jumped from my 75% when batch sparging to 87%!! Also, the crush on the grains was better, but it was still a noticeable different.

Guess I am never skipping a mash out again!

chode720 said:

So, I just wanted to give an update on this post.....

I just brewed today and did a mash out this time. With this, my efficiency jumped from my 75% when batch sparging to 87%!! Also, the crush on the grains was better, but it was still a noticeable different.

Guess I am never skipping a mash out again!

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This is some great info here! I just started fly sparging on the last few brews since I got my HLT working. I noticed a very minimal efficiency rise also. But have not yet tried a mash out.

I plan to soon recirculate through a coil in my HLT...just need to get a pump and things set up. Is this what you are doing? Is a mash out still going to help efficiency with HERMS?

ajf said:

I've been fly sparging for 17 years. For many of those years, I got 75% efficiency. Then I started doing a mash out, and my efficiency instantly increased to 85%.
-a.

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First off I am new at brewing, so my views are limited. I tried the fly sparge with limited luck. After several batches I did a mash out. WOW 78%efficiency, then 80%, and yesterday 84% efficiency. I can't help much, but this has worked for me. For the last 4 brew!! Best of luck!!

I fly sparge and I do a mashout routinely. My efficiency is usually right at 75% or just a little higher. IMO, efficiency is most affected by how finely you mill the grain. The sparge water dropping slightly below the top of the grain bed likely had little or no effect on your efficiency. Also IMO, chasing after high efficiency isn't worth the effort. Knowing what to expect is much more important to me. 75% is just fine. Pretty good actually. If you can do that consistently, you are golden.

Catt22 said:

I fly sparge and I do a mashout routinely. My efficiency is usually right at 75% or just a little higher. IMO, efficiency is most affected by how finely you mill the grain. The sparge water dropping slightly below the top of the grain bed likely had little or no effect on your efficiency. Also IMO, chasing after high efficiency isn't worth the effort. Knowing what to expect is much more important to me. 75% is just fine. Pretty good actually. If you can do that consistently, you are golden.

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I agree that the crush does make an impact. My LHBS precrushes their 2-row and it's a much finer crush than their mill can do. When I would batch sparge with the better crush my efficiency would go up to 80%. So I think how well u can rinse the sugars makes a huge impact

I'm also not trying to chase the best efficiency each time, but want to be consistent and hey if I can get 88-90% each time, why not. Saves me a couple $$ on grain, which is great for brewing on a budget

Unless your efficiency is excessively low (less than 65%), it's more important to get consistent numbers than high ones. Additionally, excessively high efficiency MAY impact wort quality.

From www.braukaiser.com:

The more water that is available for sparging, the more extract can be rinsed from the grain. But it should be kept in mind that the quality of the wort diminishes as lautering continues. The wort's extract content gets lower and lower while the buffering capacity gets weaker. The latter can cause a raise of the pH in the grain bed (especially when brewing liquor high in alkalinity is used for sparging) which leads the the excessive extraction of husk tannins (a major cause of astringent beer taste). This and the desired pre-boil volume limit how much sparging can be done and thus the efficiency of fly sparging. But if done correctly fly sparging yields a better lauter efficiency than batch sparging for the same amount of sparge water.

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As has already been stated, grain crush is the factor to likely have the biggest impact on efficiency, particularly in your case (based on your experience with LHBS crushed grain). Tighten your mill roller gap a bit if you can.

Consider monitoring (and adjusting) pH like Bobby says. It may increase your efficiency, but more importantly, it will increase your wort quality (notice a theme here?).

Otherwise, if you're happy with the quality of your beer, you should be happy with the numbers you're achieving.

Yuri_Rage said:

As has already been stated, grain crush is the factor to likely have the biggest impact on efficiency, particularly in your case (based on your experience with LHBS crushed grain). Tighten your mill roller gap a bit if you can.

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I dont have a grain mill yet. I'm just using the one at my LHBS, but they crush their 2-row on a different mill, with a tighter gap.

Yuri_Rage said:

Consider monitoring (and adjusting) pH like Bobby says. It may increase your efficiency, but more importantly, it will increase your wort quality (notice a theme here?).

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As I stated before, I dont think its a pH issue. I have just started adjusting my water and the quality of my wort and finished beer has improved dramatically.

Yuri_Rage said:

Otherwise, if you're happy with the quality of your beer, you should be happy with the numbers you're achieving.

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If anything, my wort quality is still as great as it was before. I just switched to fly sparging, so I'm doing a few batches at a higher efficiency and since the wort quality is great, I'm assuming the finished product will be as well. No harm in having an ~85% efficiency, if my wort quality does not suffer.

I didn't intend to be argumentative, just helpful.

chode720 said:

As I stated before, I dont think its a pH issue. I have just started adjusting my water and the quality of my wort and finished beer has improved dramatically.

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Without monitoring pH, you cannot rule it out. In fact, now that you're altering your water, it may be even more important.

chode720 said:

No harm in having an ~85% efficiency, if my wort quality does not suffer.

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There's no harm in CONSISTENTLY achieving 85% efficiency if the wort quality doesn't suffer. Since you're already getting consistent numbers and you're happy with the wort quality, make one minor change at a time. Read Kai's website (the one I linked above) - he's got some really good info on understanding efficiency and pinpointing losses.

Yuri_Rage said:

I didn't intend to be argumentative, just helpful.

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I know.... I get defensive sometimes....

As I have learned, there is a ton of experimentation and question marks with brewing. Yes, there can be some negatives from over-sparging and getting to high and efficiency, but having a high efficiency can be a good thing too. :rockin:

I am brand new this forum and to all grain brewing - tried my first batch yesterday. Ended up with a low original gravity which led me to research and find this post - a mash out is definitely part of my process next time. Thanks to you guys who provided that insight.

I have a question regarding the discussion of high efficiency vs. wort quality. My reading and googling has indicated that you should stop sparging when the wort gets to 1.008 specific gravity in order to prevent the extra tannins and off-flavors.

http://***********/stories/wizard/a...wizard/960-key-to-wort-volume-a-removing-trub

http://www.howtobrew.com/section3/chapter17.html

Do you guys test specific gravity as you sparge? Have you found this guideline to work well?

LarryD said:

I am brand new this forum and to all grain brewing - tried my first batch yesterday. Ended up with a low original gravity which led me to research and find this post - a mash out is definitely part of my process next time. Thanks to you guys who provided that insight.

I have a question regarding the discussion of high efficiency vs. wort quality. My reading and googling has indicated that you should stop sparging when the wort gets to 1.008 specific gravity in order to prevent the extra tannins and off-flavors.

http://***********/stories/wizard/a...wizard/960-key-to-wort-volume-a-removing-trub

http://www.howtobrew.com/section3/chapter17.html

Do you guys test specific gravity as you sparge? Have you found this guideline to work well?

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How are you sparging? With batch sparging I was stirring every 20min and getting around 75% With fly sparging and no stirring, I got a few points higher. I think I will try a mash-out next time just for experimental purposes.

I dont have enough experience to answer the 1.008 question (nor the capacity to measure it).

Welcome to the forum.
If you are fly sparging, I think that a mash-out is a good idea.
If you are batch sparging, I think that a mash out is a waste of time as you can do a combined mash out and sparge simply by adjusting the temperature of the sparge water.
As for stopping sparging when the gravity gets to 1.008, this is a rule of thumb. Some say stop at 1.008, others say 1.010, and yet others say 1.012. It isn't so much the gravity of the final runnings as the pH of the runnings that matters. As the gravity of the runnings decrease, the pH of those runnings increase, and the pH is the factor that determines whether or not you will extract tannins.
If you batch sparge, you probably won't have to bother about this. Every time I've batch sparged, the final runnings have always been > 1.012, and I've never had a problem with tannins.
If you fly sparge, it is very easy to over-sparge, and I have had problems with tannin extraction as a result of this, although you can minimize this problem by acidifying the sparge water.
Testing the gravity of the runnings with an hydrometer takes too long for me as hydrometer readings at high temperatures (even with temperature correction) are inaccurate, and I don't want to wait for the sample to cool. I use a refractometer to monitor the runnings, and stop the sparge when the brix value drops below 3 (about 1.012). Stopping at this value does not seem to make any measurable difference to my efficiency, and since I have been doing this, I have had no tannin problems.

-a.

LarryD said:

Do you guys test specific gravity as you sparge? Have you found this guideline to work well?

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I have yet to test the gravity of the final runnings of my sparge, but also have not run into any tannin issues yet. I know it would be probably advisable to test every time, but I figure that I'm not going to worry about something (and test for it) if I'm not having an issue.

That being said, a good way to avoid over sparging when fly sparging is only using enough sparge water to get to your desired volume in your kettle. I know some people will keep adding sparge water, maintaining an inch above their grain bed the whole time, and stoping once they reach their kettle volume.

However, I have been only adding enough water to fill up my kettle (using the same amount of water that Beersmith tells me to use for batch sparging). I am able to fill my kettle to my desired volume and there is generally less than 1 qt of water left in the grain bed.

If you have a fairly standard process you can easily measure the last runnings a couple of times to get a feel for where your gravity and pH are at. It may take some tweeking but after you've done that you'll have a good 'seat-o-the-pants' gage as to whether you're oversparging. Then you won't need to measure anymore. Just catch the sample and cool it as you bring the wort up to a boil (you've got at least an hour right?). I always catch a sample of the wort into the kettle preboil anyway so this is just one more sample.

I normally check gravity of the final runnings with a refractometer (I stop at 2 brix) but I'd be curious to check pH as well - what is the limit of the pH before you stop sparging ?

I also fly sparge, For mash-out I add 2.5qt of boiling water to the MLT and stir, wait 5 mins for grains to settle, vorlauf and sparge.
What is your mash-out method ?

ajf said:

Welcome to the forum.
If you are fly sparging, I think that a mash-out is a good idea.
If you are batch sparging, I think that a mash out is a waste of time as you can do a combined mash out and sparge simply by adjusting the temperature of the sparge water.
As for stopping sparging when the gravity gets to 1.008, this is a rule of thumb. Some say stop at 1.008, others say 1.010, and yet others say 1.012. It isn't so much the gravity of the final runnings as the pH of the runnings that matters. As the gravity of the runnings decrease, the pH of those runnings increase, and the pH is the factor that determines whether or not you will extract tannins.
If you batch sparge, you probably won't have to bother about this. Every time I've batch sparged, the final runnings have always been > 1.012, and I've never had a problem with tannins.
If you fly sparge, it is very easy to over-sparge, and I have had problems with tannin extraction as a result of this, although you can minimize this problem by acidifying the sparge water.
Testing the gravity of the runnings with an hydrometer takes too long for me as hydrometer readings at high temperatures (even with temperature correction) are inaccurate, and I don't want to wait for the sample to cool. I use a refractometer to monitor the runnings, and stop the sparge when the brix value drops below 3 (about 1.012). Stopping at this value does not seem to make any measurable difference to my efficiency, and since I have been doing this, I have had no tannin problems.

-a.

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I picked up about 7-8 points with a mash out just before starting the "drip". Not only did efficiency improve, but was able to more accurately dial in the malt profile by locking in the rest time with a mash out. My beers of late were over attenuating as a result of an extended rest (due to the lengthy fly sparge). Once I started mashing out, my malt profiles improved.

A question for the recirculators, how do you mash out? Do you continue to recirculate until temp reach 165 or 170 degrees consistently in the MLT? If you fly sparge do you try to keep the sparge water at 170degrees or hotter? In the MLT do you maintain the sparge water at the top of the grain bed until you hit your target pre-boil volume?

I'm asking because my eff on my sunday brew was horrible, 56%. All my previous beers to date have been at least 70% but never 75-80%. I modify my water and I get a good crush.

Thanks for your input.

Bru said:

I normally check gravity of the final runnings with a refractometer (I stop at 2 brix) but I'd be curious to check pH as well - what is the limit of the pH before you stop sparging ?

I also fly sparge, For mash-out I add 2.5qt of boiling water to the MLT and stir, wait 5 mins for grains to settle, vorlauf and sparge.
What is your mash-out method ?

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Most modern articles that I have read recommend keeping the pH below 6.0
I don't know what my pH was when I had the problems, but I do know that my final runnings were very low (probably below 1.008) and that I was using alkaline water for the sparge. I started treating the sparge water with gypsum which improved matters considerably, and (after I got the refractometer) by stopping the sparge by 2.5 - 3 brix. I've had no problems since doing this.

For a mash out, I add between 1 and 2 gallons of near boiling water (depending on the amount of grain). I try to reach a temperature in the upper 160's. I stir well to mix, and leave it for 15 minutes before vorlaufing and starting the sparge.

-a.

To answer an earlier question, I was fly sparging. Does anybody have any recommendations on refractometers? That seems the convenient and accurate way to go.

LarryD said:

To answer an earlier question, I was fly sparging. Does anybody have any recommendations on refractometers? That seems the convenient and accurate way to go.

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If you are fly sparging, they are great for telling you when to stop sparging.
They probably aren't quite as accurate as an hydrometer, but not having to cool the sample makes them invaluable; plus they are a lot more robust than hydrometers.
I don't find them at all accurate for calculating the FG, but I use a finishing hydrometer for that.

-a.

I fly sparge and I'm getting only 50-60% effic! My crush is from a local brewery, stainless steel false bottom in a converted keg, sparging with 180 deg water for 45 min or so. I tried stirring the mash right before sparging but it didn't help. I need to try a mash out- that may help. Also, I sparge to volume but always keep an inch of water of the grains, even at the end. Could this be my issue??