Is my fly sparge a waste of time? Need help and common sense!

[wilserbrewer]

While I agree, it does seem intuitive that it would take some amount of time for the sugar to equilibrate from the grain to sparge water during a batch sparge, however Denny Conn, a well respected pioneer of the batch sparge process found that the time to equilibrate was about the time it takes for a “good” stir, whatever that is.

I believe Denny claims to have tried it both ways and found little to no difference, and therefore a rest is not required according to him.

Perhaps the grain particles being so small, the sugar is rinsed rather quickly.

The sponge example should perhaps include squeezing the sponge a few times to replicate the action of a “good stir” lol jk

 

[doug293cz]

Soak a sponge in salt water

Then dip it in clean water quickly, soak it in the salt water again then dip it in a second bowl of clean water and let it sit for 5 minutes. Taste both bowls of clean water.

Which one extracted more salt?

There is a contact time factor to allow the new concentration to equilibrate in the liquid solution and the grain particles - I don't know what the correct amount of time is, but a few minutes 5-10 seems reasonable, but there would logically be a point of no-gain where equilibrium is reached. I would be very surprised if that happens completely within 2 minutes (the amount of time it takes to stir and run off)

While I agree, it does seem intuitive that it would take some amount of time for the sugar to equilibrate from the grain to sparge water during a batch sparge, however Denny Conn, a well respected pioneer of the batch sparge process found that the time to equilibrate was about the time it takes for a “good” stir, whatever that is.

I believe Denny claims to have tried it both ways and found little to no difference, and therefore a rest is not required according to him.

Perhaps the grain particles being so small, the sugar is rinsed rather quickly.

The sponge example should perhaps include squeezing the sponge a few times to replicate the action of a “good stir” lol jk

Wilser is correct. The sponge alone is a bad model for a stirred batch sparge. Holding the sponge in clean water and squeezing it several times, is a better analogy for stirring.

The goal in a batch sparge is to homogenize the extract (sugar) concentration throughout the entire volume, prior to running off. Stirring can accomplish this in a short period of time. Without stirring, you are depending on diffusion to homogenize the wort, which will take a significantly longer period of time.

There is a situation where a dwell after adding the sparge water can improve efficiency. This happens when the conversion is not complete at the end of the initial mash, and no mashout is done. In this case, conversion can continue during a sparge dwell, resulting in an increase in the conversion efficiency component of mash efficiency. However, getting complete conversion prior to initial run-off will still result in better mash efficiency.

Brew on

 

[luckybeagle]

Really enjoying this discussion; thanks everyone for contributing thus far.

 

[TheMadKing]

Wilser is correct. The sponge alone is a bad model for a stirred batch sparge. Holding the sponge in clean water and squeezing it several times, is a better analogy for stirring.

The goal in a batch sparge is to homogenize the extract (sugar) concentration throughout the entire volume, prior to running off. Stirring can accomplish this in a short period of time. Without stirring, you are depending on diffusion to homogenize the wort, which will take a significantly longer period of time.

There is a situation where a dwell after adding the sparge water can improve efficiency. This happens when the conversion is not complete at the end of the initial mash, and no mashout is done. In this case, conversion can continue during a sparge dwell, resulting in an increase in the conversion efficiency component of mash efficiency. However, getting complete conversion prior to initial run-off will still result in better mash efficiency.

Brew on

Consider me very surprised and corrected

I would have expected that even with stirring, there would still be some time needed to equilibrate the solution

Another factor that you've not mentioned and that I missed, is that batch sparging is typically done successively. So even if there is a time factor involved, it's reduced by the fact that clean water is added a second and even third time in some cases.

the analogy then becomes

Dip the sponge in clean water and then dip it in clean water again immediately, which one has more salt

 

[doug293cz]

Consider me very surprised and corrected

I would have expected that even with stirring, there would still be some time needed to equilibrate the solution

Another factor that you've not mentioned and that I missed, is that batch sparging is typically done successively. So even if there is a time factor involved, it's reduced by the fact that clean water is added a second and even third time in some cases.

the analogy then becomes

Dip the sponge in clean water and then dip it in clean water again immediately, which one has more salt

I believe most brewers who use a batch sparge, do a single batch sparge. There are some who do a double batch sparge. There may even be some who routinely do a triple batch sparge, but they are a small minority of batch spargers. Each successive batch sparge recovers a little more extract (sugar) from the grain bed, but each additional sparge has less benefit than the previous. This is all laid out in the chart in the 2nd post in this thread. The chart assumes that the wort has been homogenized prior to each run-off.

Typical procedure for batch sparging is to:

1. Run off wort
2. Add sparge water to MLT
3. Stir sparge water and grain
4. Run off wort
5. repeat from step 2 as desired

If the stir in step three is adequate, then the desire for homogenized wort will be met.

So, your: "Dip the sponge in clean water and then dip it in clean water again immediately, which one has more salt" should become: "Dip the sponge in clean water, then squeeze multiple times, transfer the sponge to clean water, then squeeze multiple times. Which of the two originally clean water masses has more solute (sugar, salt, whatever)?" The answer is the first water that the sponge was dipped and squeezed in has more solute.

Brew on

 

[luckybeagle]

Whenever I would batch sparge in my igloo cooler for large, high gravity batches, I had no choice but to double or triple batch sparge--I simply did not have the space to sparge with the amount of water needed to reach preboil volume. I remember these making for long brewdays, but IIRC I was still hitting 75% efficiency or greater on those high OG batches. This is what I would achieve on normal gravity batches employing a single batch sparge, so I'm of the mindset that a double sparge results in slightly better efficiency given the tendency for higher grain bills to result in lower numbers (I probably should've been hitting 65 or 70%). This was with a braided stainless line in the bottom of the tun and not a legit false bottom.

For my process, I usually dumped in the sparge water (which was hot, about 190F--at least for the first sparge) fairly aggressively from the kettle and let that mix up the grains, then immediately began vorlaufing/recirculating with the help of a pump. I moved away from letting the grain sit and settle once I got the pump. I don't recall my efficiency improving or reducing, but that's just one anecdote. I also stopped letting the grain sit based on Denny's writings.

 

[VikeMan]

so I'm of the mindset that a double sparge results in slightly better efficiency given the tendency for higher grain bills to result in lower numbers (I probably should've been hitting 65 or 70%).

Yep. Double batch sparging ("all other things being equal") yields higher mash efficiency than single. And that tendency for larger grain bills to result in lower efficiency (given same sparge method) is quite simple (ok, at least not rocket science) to calculate. I've seen a lot of folks say things like "I get 80% mash efficiency with most of my beers, but only 70% with high gravity beers," as if it's something binary. But if they were to plot their mash efficiencies vs. grain bill size, they'd find a pretty smooth curve.

 

[luckybeagle]

Yep. Double batch sparging ("all other things being equal") yields higher mash efficiency than single. And that tendency for larger grain bills to result in lower efficiency (given same sparge method) is quite simple (ok, at least not rocket science) to calculate. I've seen a lot of folks say things like "I get 80% mash efficiency with most of my beers, but only 70% with high gravity beers," as if it's something binary. But if they were to plot their mash efficiencies vs. grain bill size, they'd find a pretty smooth curve.

Agree completely on it being linear. There's no way the mash tun *knows* to hit 75% efficiency at 15 lbs, and then arbitrarily decides to drop to 65% at 16 lbs.

 

[doug293cz]

Yep. Double batch sparging ("all other things being equal") yields higher mash efficiency than single. And that tendency for larger grain bills to result in lower efficiency (given same sparge method) is quite simple (ok, at least not rocket science) to calculate. I've seen a lot of folks say things like "I get 80% mash efficiency with most of my beers, but only 70% with high gravity beers," as if it's something binary. But if they were to plot their mash efficiencies vs. grain bill size, they'd find a pretty smooth curve.

See post #2 in this thread

Agree completely on it being linear. There's no way the mash tun *knows* to hit 75% efficiency at 15 lbs, and then arbitrarily decides to drop to 65% at 16 lbs.

Not quite linear, but definitely monotonically decreasing with increasing grain bill size. Again, see post #2 this thread.

Brew on

 

[VikeMan]

See post #2 in this thread

Lol. I guess someone besides me has plotted this stuff. I should have read the whole thread! The calculations I've done were in the context of predicting changes in mash efficiency when changing grain bill size and/or sparge methods, given particular (user) brew house setups (mash tun dead space, etc), i.e. constant volume wort losses.

 

[doug293cz]

Lol. I guess someone besides me has plotted this stuff. I should have read the whole thread! The calculations I've done were in the context of predicting changes in mash efficiency when changing grain bill size and/or sparge methods, given particular (user) brew house setups (mash tun dead space, etc), i.e. constant volume wort losses.

Have you seen this spreadsheet? A modified version was used to create the chart in post #2. The modifications were only to allow multiple data points to be calculated simultaneously.

Brew on

 

[VikeMan]

Have you seen this spreadsheet? A modified version was used to create the chart in post #2. The modifications were only to allow multiple data points to be calculated simultaneously.

No, but I'll check it out. Thanks!

 

[eric19312]

In response to OP's title question...

I do like fly sparging and don't see it as any more or less time consuming on my system. You likely have different constraints than me so it may be a time waster for you.

I use household natural gas on the larger banjo burners to heat and boil and just don't generate the amount of heat I might be able to get out of high pressure propane on same burners or with jet burners or some of the high amp electric systems for that matter. But my burners are clean, reliable, cheap to run and I never run out of gas. They are also very quiet compared to jet burners and high pressure burners. Downside is it takes me an hour to get 20 gallons of wort from 170 to a rolling boil. Maybe a little longer.

But I start that process about 15 minutes after starting my sparge so I can sparge for an hour and then be at a rolling boil 15 minutes later. If I were batch sparging it would really take just about the same amount of time for a single batch sparge and batch sparging is more hands on...

With fly sparging I've been able to manage my entire packaging process from cleanin any dirty kegs to ending with initial cleaning of the fermentor during the combined mash and sparge. I need both pumps to fly sparge so I've been running CIP and sanitizing fermentor during boil and chill but just got a dedicated CIP pump so taking that slightly fussy timing issue out of my brew day. I don't always keg on brew day but it is convenient option for when I need it.

 

[Dog House Brew]

I too use NG and do 20 gallon batches. I’ve never timed my 170-boil time. I’m guessing in the 20min time frame. I use 20 tip jet burners.
I never liked batch sparging. Doing large batches, I hated the stiring. I never could get good numbers when batch sparging. Once I started the fly, I never looked back. I use a manifold in a 120qt cooler. I think my process improved with the addition of a Wilser bag. I initially bought the bag for ease of cleanup. I started crushing finer because I didn’t have to worry about a stuck mash. I haven’t had a stuck mash in years, but the bag adds insurance. The finer crush helped add some efficiency. The only time I stir is right after I underlet my strike water. I found that underletting greatly reduced dough balls. This also reduces the amount of stirring needed. This is the only time I stir the mash. I use a Locline as my return. I recirculate slowly until the bed is set and open to full for the duration. I also knife the bed before I start the sparge. The times I hurt my efficiencies and process came from rushing. HEX too hot to speed ramp times. Speeding up the flow on the sparge. It didn’t do anything positive for the process. I don’t get to brew often. When I do, I learned to relax. No matter what, brew day is a full day. So no, I do not think that fly sparging is a waste of time. To get the most out of the process I found that it took some refining. 1) the manifold/false bottom used. 2)Crush adjustment 3) Sparge flow probably had the most impact.

 

[eric19312]

Is that jet burner noisy on NG? Maybe I should try one of those.
I also got a wilser bag for my mash tun for exact same reasons - cleanup and stuck sparge insurance. I've not had a stuck sparge since I started using it.

 

[Dog House Brew]

Is that jet burner noisy on NG? Maybe I should try one of those.
I also got a wilser bag for my mash tun for exact same reasons - cleanup and stuck sparge insurance. I've not had a stuck sparge since I started using it.

I love the burners. It does make a little noise, but not obnoxious. I plumbed my rig with a 3/4” flex line Rig has 3/4” iron pipe. Burners take 1/2, just reduced right at burner. I can run both full go w/o starving them. Love the Wilser bag too.

 

[day_trippr]

I think the worst of the jet burner noise is found in the high pressure propane jetted versions.
There's a local nano with a 2 barrel rig running on 20 psi propane with a pair of 22 tip jets in a stupid tight store-front space and honestly I could never brew on that thing without some excellent headphones...

Cheers!

 

[Dog House Brew]

That would suck! Let alone the heat output in a tight space.

 

[luckybeagle]

This is incredibly frustrating. I really need a grain mill.

Brewed a 5 gallon batch of Barleywine tonight and missed my numbers by a huge margin.

Recipe and stats:

• 20 lbs Maris Otter
• 0.5 lbs Caramalt
• 0.5 lbs Dark Crystal

Mash at 150F for 75 minutes, recirculating on LOW flow.
Mash thickness: 1.2
Mash pH was 5.3
Mashout at 170 for 10
Fly sparge with 5.3 pH water to 6.5 gallons preboil over the course of 1 hour
Stir the mash every 20 minutes during mash and just after mashout (followed by pump vorlauf until runnings cleared)

Preboil OG: 1.073. Target: 1.081 at 70% efficiency - apparent efficiency = 58%
Post Boil Gravity: 1.087. Target: 1.106 - missed it by 19 points

--Side note, how does gravity jump from 1.081 to 1.106 after just a 60 minute boil?? I'm getting this jump in both BrewTarget and BrewersFriend software.--

I *thought* I was only 2 points off on my preboil gravity but it turns out I had my boil volume plugged in as 7 gallons into my brew software rather than 6.5, so I was actually off by 8 points. I proceeded to hop accordingly. After I boiled, chilled, and took an SG reading, I realized I was 19 points off from target SG, which sent my BU:GU to 0.78.

Is this beer ruined? I was aiming for a BU:GU of about 50. Should I boil up some DME? Add a sugar-water solution to help balance the BU:GU ratio back down by adding gravity units? I'm afraid of drying it out too much, but I'd rather have a slightly dryer beer than something that makes my mouth pucker like I'm licking a 9v battery.

 

[VikeMan]

--Side note, how does gravity jump from 1.081 to 1.106 after just a 60 minute boil?? I'm getting this jump in both BrewTarget and BrewersFriend software.--

By boiling away about 23.6% of the pre-boil volume.

(OGpost -1 ) = ((OGpre -1 ) x VOLpre) / VOLpost

 

[TheMadKing]

This is incredibly frustrating. I really need a grain mill.

Brewed a 5 gallon batch of Barleywine tonight and missed my numbers by a huge margin.

Recipe and stats:

• 20 lbs Maris Otter
• 0.5 lbs Caramalt
• 0.5 lbs Dark Crystal

Mash at 150F for 75 minutes, recirculating on LOW flow.
Mash thickness: 1.2
Mash pH was 5.3
Mashout at 170 for 10
Fly sparge with 5.3 pH water to 6.5 gallons preboil over the course of 1 hour
Stir the mash every 20 minutes during mash and just after mashout (followed by pump vorlauf until runnings cleared)

Preboil OG: 1.073. Target: 1.081 at 70% efficiency - apparent efficiency = 58%
Post Boil Gravity: 1.087. Target: 1.106 - missed it by 19 points

--Side note, how does gravity jump from 1.081 to 1.106 after just a 60 minute boil?? I'm getting this jump in both BrewTarget and BrewersFriend software.--

I *thought* I was only 2 points off on my preboil gravity but it turns out I had my boil volume plugged in as 7 gallons into my brew software rather than 6.5, so I was actually off by 8 points. I proceeded to hop accordingly. After I boiled, chilled, and took an SG reading, I realized I was 19 points off from target SG, which sent my BU:GU to 0.78.

Is this beer ruined? I was aiming for a BU:GU of about 50. Should I boil up some DME? Add a sugar-water solution to help balance the BU:GU ratio back down by adding gravity units? I'm afraid of drying it out too much, but I'd rather have a slightly dryer beer than something that makes my mouth pucker like I'm licking a 9v battery.

I would also add a couple comments, and please don't take this the wrong way, but I think you need to recalibrate your expectations depending on the beer you're brewing.

You brewed a barleywine so an efficiency in the mid 65% range is not unreasonable. 70% is ambitious IMO

A mash thickness of 1.2 reduces your efficiency as well. Mash thinner on bigger beers especially, and you'll have a little more luck.

You sparged to your normal preboil amount for a 60 min boil which left a bunch of sugar behind. On big beers try a 90 minute or even 120 minute boil. It allows you to sparge far more and get more of your sugars out.

Maris Otter is a good base malt choice, but its very common to add some simple sugars to a beer this big to save yourself some pain. So I will usually add 1lb of brown sugar or candi syrup to mine.

I don't think the beer is ruined. It might need some time for the hops to settle down, but there's nothing wrong with a hoppy barleywine.

 

[eric19312]

I'd start checking conversion efficiency. This is pretty easy to do but requires some planning before you start brewing. What you want to know is your pre-sparge gravity target that indicates all the starches in the mash have been converted to sugar. Braukaiser explains it the best and posted a really useful table - link to table and full article below:

http://braukaiser.com/wiki/index.php/Understanding_Efficiency
In your scenario with 1.2 mash thickness you would be targeting mid-way between 1.15 and 1.24 on the table so I'd eyeball that at 1.099 SG. So I'd start taking refractometer measurements of my mash starting at about 30 minutes into the mash and take another measurement every 15 minutes. With this big and thick of a mash you might not get to 1.099 for 2-3 hours but if you are tracking the data over time you can make a judgement call when you are close enough and start your mash out and accept what you have.

Also once you know what to expect and have some data you can start tweaking things to see if you can improve on last time. Crush is certainly low hanging fruit, if a mill is not in your current budget try getting LHBS to double mill next batch and plot its curve. I'd also look into channelling. Maybe after every 15 minute refractometer measurement you should give the mash a stir.

On the other hand if you are getting great conversion efficiency then you need to focus on your sparge/lauter technique. I believe channeling is the enemy of fly sparging. Going slow is one key. Mixing the grain bed before the mash out might help. I did something as simple as moving my dip tube from 3" from the edge of the kettle to the middle of the kettle and think I am seeing improved performance. Also are you sparging to dry grain bed or sparging to kettle volume target. I understand best practice is to keep adding water to the top keeping the grain bed fully covered until you hit target volume in your kettle. Then you have to drain the mash tun into another vessel or drain before cleaning.

Finally for the big beers...no harm in adding some sugar right before flame out if your refractometer tells you you are coming in low. Table sugar up to 10% shouldn't be detrimental to a 1.080+ beer.

Really that whole article posted by Kaiser is excellent and I strongly recommend it.