HERMS Sparging tips

[BrewRunning]

Ok, I did my first brew last night on my Spike HERMS system and it was my first time fly sparging. Overall brew day was a success but, I feel like I could improve on the fly sparging.

My process;

Mashed at 154 with constant recirculation. 1 hour.

At the end of the mash I raised temp to 168 to mash out.

Began transferring wort from MT to BK

Began transferring from HLT to MT at same rate. Maintaining approx. 1" over grain bed.

Once my boil volume was reached (about 45 minutes), stopped sparging.

Here's my issues;

Est. preboil gravity was 1.071 and measured was 1.061

After shutting the sparge off I was still getting wort that measured 1.035 from the MT. Seems like I left a lot of sugar behind.

I also had nearly 9 gallons of wort now in the MT left over from the sparge. Seems like a lot of waste.

Questions;

Am I supposed to be maintaining the water over the grain bed for the ENTIRE sparge? Or, should I have stopped the transfer from the HLT once I knew my sparge volume had been transferred over to the MT?

Did I not sparge slow enough to rinse all of the sugars properly?

Any other suggestions on how to improve my sparging process with the HERMS system?

Learning as I go, thanks for any input. You have all been very knowledgeable and helped me tremendously so far!

 

[Bobby_M]

Ok, I did my first brew last night on my Spike HERMS system and it was my first time fly sparging. Overall brew day was a success but, I feel like I could improve on the fly sparging.

My process;

Mashed at 154 with constant recirculation. 1 hour.

At the end of the mash I raised temp to 168 to mash out.

Began transferring wort from MT to BK

Began transferring from HLT to MT at same rate. Maintaining approx. 1" over grain bed.

Once my boil volume was reached (about 45 minutes), stopped sparging.

Here's my issues;

Est. preboil gravity was 1.071 and measured was 1.061

After shutting the sparge off I was still getting wort that measured 1.035 from the MT. Seems like I left a lot of sugar behind.

I also had nearly 9 gallons of wort now in the MT left over from the sparge. Seems like a lot of waste.

Questions;

Am I supposed to be maintaining the water over the grain bed for the ENTIRE sparge? Or, should I have stopped the transfer from the HLT once I knew my sparge volume had been transferred over to the MT?

Did I not sparge slow enough to rinse all of the sugars properly?

Any other suggestions on how to improve my sparging process with the HERMS system?

Learning as I go, thanks for any input. You have all been very knowledgeable and helped me tremendously so far!

You were getting channeling in the grainbed if your runoff was still that high in gravity. Less likely but your conversion may not have been completed at the start of the sparge. You can rule that out with a gravity test before sparging.

To avoid channels, stop recirc, stir well, reset grained twice; once in the middle of the mash and once before ramping to mash out. You can also rake the top inch of the grain a couple times during the sparge. Rice hulls will also help.

 

[Beardless]

I have a HERMS system (not electric, not spike, but hey it’s all brewing) and agree with @Bobby_M in one of those two things- channeling or not converted completely at start.

If you hadn’t already I would make sure your thermometers are all in cal as well (could’ve started on the low end temp wise and had more conversion happen during the ramp, never heard of such a thing but just an idea of another worthwhile, easy check). I have a couple of spike thermometers and they seem to cal best in smaller ranges (they don’t stay in cal for the entire range of like 0-212 degF). So for mine I made sure they were calibrated most accurate from like 110 to 180 degF for my mash thermometers; 50-180 degF (ish) for my boil kettle thermometer.

With my system I typically drain all the wort / sparge water from the MLT during transfer, but it is a learning curve to dial in water amounts on most systems. I usually turn off sparge water and drain the last of the wort to obtain my target pre boil volume.

There is also the possibility (if you don’t like waste and do have reasonable gravity and sparge water left during the last runnings) of doing some parti-gyle beers. I’ve always liked the idea but it seems like it’d be a long day.

 

[BrewRunning]

You were getting channeling in the grainbed if your runoff was still that high in gravity. Less likely but your conversion may not have been completed at the start of the sparge. You can rule that out with a gravity test before sparging.

To avoid channels, stop recirc, stir well, reset grained twice; once in the middle of the mash and once before ramping to mash out. You can also rake the top inch of the grain a couple times during the sparge. Rice hulls will also help.

Thank you both. After your input, and reading through some other threads, I think channeling may be one of the issues. During mash recirculating I ran the pump fully open and didn’t stir the mash at all. I’ll try a slower recirculation next time along with your recommendations for stirring.

As far as sparse volume, was I correct to continue pumping water from HLT to MT all the way through until boil volume was reached?

Thanks,

 

[Bobby_M]

There are a lot of schools of thought on whether the MLT should run dry at the end or if it should be full. There can be a compromise but if you have to fill the HLT to cover your whole HERMS coil anyway, it's not really being wasted by running into the mash except that could have been used for cleaning later. When I drag out the old 3 vessel HERMS system just to be a glutton for punishment, I'll continue sparging until I am 3 gallons shy of my preboil volume. That way the mash is a little dry up top without completely collapsing the grainbed.

Definitely do not pump at full volume. Do stir occassionally. After the last stirring, just recirc very very slowly until the runoff is chunk free, then sparge. Also, you're pumping your sparge water through the HERMS coil right?

 

[JaymzMF]

Missing my Preboil gravity with my HERMS setup was mostly all due to me not stirring the mash. I stir several times now to ensure nice even temps throughout.
I'm assuming you are also running your sparge water through the HERMS coil to clear out that trapped wort? If not, you'll want to do that as well.
I like to get close to exactly the amount of sparge water I need to get to boil volume. Beersmith does a great job of nailing that for me. Then I just run all of my sparge water. Then, it's also a matter of dialing in your equipment profiles. Will probably take several brew days to get that dialed in. Good luck!

Edit: I just realized with a Spike setup, you probably can't start with the exact sparge water needed as your HERMS in in your HLT. Mine is a separate smaller dedicated HERMS pot, so my HLT is separate from that. But as long as you stir and run your sparge through the coil as well, you can just watch until you hit your boil volume.

 

[BrewRunning]

Thank you both. Will definitely do some things differently next brew day.

Yes, I do run the sparge though my coils.

Although I can’t have only the sparge volume in the HLT, I can monitor the amount going to the MT using the etched markings.

Cheers

 

[doug293cz]

I disagree with the previous posters who think channeling is to blame. If you have channeling, the sparge water bypasses most of the grain bed, so only picks up sugar from the grain close to the channels. Grain "far away" from the channels doesn't get rinsed. The fact that you are only rinsing a fraction of the grain bed, means the sparged wort will become more dilute faster than if you were rinsing the entire grain bed. Thus with channeling you get lower SG wort sooner during the sparge. This is the opposite of your problem, which is why I don't think channeling is the culprit.

Your sparge process appears to be basically sound. Other possibilities for low SG are incorrect calculation of estimated SG and low conversion efficiency in the mash. We need more information (grain bill, strike volume, pre-boil volume) to determine whether the first possibility is in play. Conversion efficiency can be directly measured using the method here. Your conversion efficiency should be 90%, or better, with 95% - 100% being achievable with optimized crush and mash time. You should crush as fine as you can without it limiting recirculation too much. If that doesn't get you good conversion efficiency, then mash longer. Adding some higher temp rests, but still below mash out, may also help with conversion efficiency.

Your wort SG at end of sparge was abnormally high, as typical is in the range of 1.010 - 1.015 (and higher for high gravity beers.) High ending SG is probably due to using too much strike water, thus forcing inadequate sparge volume before hitting your pre-boil volume target.

Brew on

 

[BrewRunning]

I disagree with the previous posters who think channeling is to blame. If you have channeling, the sparge water bypasses most of the grain bed, so only picks up sugar from the grain close to the channels. Grain "far away" from the channels doesn't get rinsed. The fact that you are only rinsing a fraction of the grain bed, means the sparged wort will become more dilute faster than if you were rinsing the entire grain bed. Thus with channeling you get lower SG wort sooner during the sparge. This is the opposite of your problem, which is why I don't think channeling is the culprit.

Your sparge process appears to be basically sound. Other possibilities for low SG are incorrect calculation of estimated SG and low conversion efficiency in the mash. We need more information (grain bill, strike volume, pre-boil volume) to determine whether the first possibility is in play. Conversion efficiency can be directly measured using the method here. Your conversion efficiency should be 90%, or better, with 95% - 100% being achievable with optimized crush and mash time. You should crush as fine as you can without it limiting recirculation too much. If that doesn't get you good conversion efficiency, then mash longer. Adding some higher temp rests, but still below mash out, may also help with conversion efficiency.

Your wort SG at end of sparge was abnormally high, as typical is in the range of 1.010 - 1.015 (and higher for high gravity beers.) High ending SG is probably due to using too much strike water, thus forcing inadequate sparge volume before hitting your pre-boil volume target.

Brew on

Thanks for adding some new things to consider.

I have my batch size in beersmith set to 16.5 gallons to account for losses in fermenter.

30lbs 2-row
9lbs Flaked wheat
9lbs White Wheat

Mash PH was 5.35
End of boil PH was 5.02

I have my grain mill set to .30, did not crush the flaked wheat.

I mashed in with 17gallons, mashed at 154 for 1 hour and mashed out at 168. Preboil volume of 19 gallons. After 2 gallons of boil off and kettle losses, went into fermenter with 16.5-17 gallons. All calculated through BeerSmith. I don't have the program in front of me right now since I'm at work. I can't remember what I had the estimated efficiency set at. Most likely around 73%.

Mash ratio was around 1.40 since I had read to mash a little thinner when doing a recirculation mash. I used to use around 1.33. Was this too thin?

Estimated preboil gravity was 1.071, actual was 1.061. Estimated gravity post boil was 1.078, Actual was 1.064. Final runnings were still at 1.035.

The thing that confuses me the most is the high end of runnings and why so much sugar was left behind instead of getting into the wort. Obviously if those would have made it to the boil kettle the SG would have been a lot closer.

I always do a starch conversion test using iodine at the end of the mash.

 

[Beardless]

I disagree with the previous posters who think channeling is to blame. If you have channeling, the sparge water bypasses most of the grain bed, so only picks up sugar from the grain close to the channels. Grain "far away" from the channels doesn't get rinsed. The fact that you are only rinsing a fraction of the grain bed, means the sparged wort will become more dilute faster than if you were rinsing the entire grain bed. Thus with channeling you get lower SG wort sooner during the sparge. This is the opposite of your problem, which is why I don't think channeling is the culprit.

Your sparge process appears to be basically sound. Other possibilities for low SG are incorrect calculation of estimated SG and low conversion efficiency in the mash. We need more information (grain bill, strike volume, pre-boil volume) to determine whether the first possibility is in play. Conversion efficiency can be directly measured using the method here. Your conversion efficiency should be 90%, or better, with 95% - 100% being achievable with optimized crush and mash time. You should crush as fine as you can without it limiting recirculation too much. If that doesn't get you good conversion efficiency, then mash longer. Adding some higher temp rests, but still below mash out, may also help with conversion efficiency.

Your wort SG at end of sparge was abnormally high, as typical is in the range of 1.010 - 1.015 (and higher for high gravity beers.) High ending SG is probably due to using too much strike water, thus forcing inadequate sparge volume before hitting your pre-boil volume target.

Brew on

For my system I stop recirculation at/after mashout to change some hoses around and get my sparge arm setup. Wouldn’t / couldn’t the stopping of the process and then restarting “disturb” the channels if that were the issue, or is that unlikely?

Also, wouldn’t the sparging actually change the dynamics in the mash as well (thin it) due to relatively higher temp, potentially also allowing more of the bed to rinse? I’m thinking of the gray mush on top of the grain bed that often shows up.

Not disagreeing with you, since what you’re saying made me go “huh, that’s true”. But just posing the question to close the loop.

 

[doug293cz]

Thanks for adding some new things to consider.

I have my batch size in beersmith set to 16.5 gallons to account for losses in fermenter.

30lbs 2-row
9lbs Flaked wheat
9lbs White Wheat

Mash PH was 5.35
End of boil PH was 5.02

I have my grain mill set to .30, did not crush the flaked wheat.

I mashed in with 17gallons, mashed at 154 for 1 hour and mashed out at 168. Preboil volume of 19 gallons. After 2 gallons of boil off and kettle losses, went into fermenter with 16.5-17 gallons. All calculated through BeerSmith. I don't have the program in front of me right now since I'm at work. I can't remember what I had the estimated efficiency set at. Most likely around 73%.

Mash ratio was around 1.40 since I had read to mash a little thinner when doing a recirculation mash. I used to use around 1.33. Was this too thin?

Estimated preboil gravity was 1.071, actual was 1.061. Estimated gravity post boil was 1.078, Actual was 1.064. Final runnings were still at 1.035.

The thing that confuses me the most is the high end of runnings and why so much sugar was left behind instead of getting into the wort. Obviously if those would have made it to the boil kettle the SG would have been a lot closer.

I always do a starch conversion test using iodine at the end of the mash.

Ok, I did a simulation using your mash parameters for a triple batch sparge process, which usually gives results not too far away from a good fly sparge process. Conversion efficiency to get 1.061 pre-boil worked out to 85.7%, assuming your grain bill had a weighted average potential of 36 pts/lb. With that conversion efficiency, the final runnings (after 3rd batch sparge) were 1.032. So, your final runnings SG doesn't seem unreasonable. Also, the predicted pre-boil SG at 100% conversion efficiency came out at 1.070, so your estimated 1.071 wasn't out of line.

It looks like your biggest issue was incomplete conversion. The starch test gives pretty much useless results if you just measure wort, since any remaining starch will be in the grits. The best way to monitor for conversion completion (actually gelatinization and solubilization completion) is to sample the recirculating wort SG at 15 minute intervals, starting at about 45 - 60 minutes into the mash. When you get two samples the same, your mash is done (and any dissolved starch that was not converted at the second to last sample will have converted by the time of the last sample.)

In your case, at 100% conversion efficiency, your wort at the end of mash should have had an SG of 1.085 - 1.086, but you more likely had about 1.073.

You could increase your lauter efficiency a tiny amount by increasing your mash thickness to 1.25 qt/lb, which at your actual conversion efficiency would have increased the pre-boil SG to about 1.062, so the big gains are in improving conversion efficiency, not increasing lauter efficiency by increasing mash thickness.

Brew on

 

[doug293cz]

For my system I stop recirculation at/after mashout to change some hoses around and get my sparge arm setup. Wouldn’t / couldn’t the stopping of the process and then restarting “disturb” the channels if that were the issue, or is that unlikely?

Also, wouldn’t the sparging actually change the dynamics in the mash as well (thin it) due to relatively higher temp, potentially also allowing more of the bed to rinse? I’m thinking of the gray mush on top of the grain bed that often shows up.

Not disagreeing with you, since what you’re saying made me go “huh, that’s true”. But just posing the question to close the loop.

Ideally, you don't have any channeling going on during recirc. If you did have channeling during recirc, there may be a chance that stopping the flow could cause the bed to restructure, and the channels collapse, but I think that is unlikely. If you didn't have channeling during recirc, then shutting off the flow definitely won't cause the bed to restructure.

Heating from mash temp to mash out temp only decreases the wort viscosity by about 20%. Dilution with sparge water decreases the viscosity of the wort remaining in the bed much more than that, so the decrease in viscosity due to heating will have little net effect on lautering.

The "gray mush" has a name which I don't recall, but will definitely slow flow thru the bed for both recirc and lautering. May pro brewers use mash rakes to break up that surface gunk to improve flow. The gunk that collects is stuff like grain fines, coagulated protein, etc. and it just shows that the grain bed is doing an excellent job of filtering the wort.

Brew on

 

[Gnomebrewer]

I second what Doug is talking about. With my crush (about 0.035" according to the dubious markings on my grain mill) I never have maximum conversion efficiency after 60 minutes. I suspect many brewers (apart from BIABers with a fine crush) are stopping short of 95% to 100% conversion efficiency - which is quite achievable. To get there, I find a couple of stirs and a rest at the high end of conversion temperatures (about 160F) helps - I think it's more to do with extraction of starches (rather than conversion itself) that works much better at higher temperatures (which is why the iodine test won't work - the starches are still in the middle of the grain bits). This spreadsheet is useful for calculating conversion efficiency so you know when your mash is finished. Also, I find wheat needs to be crushed very fine or conversion takes a long time - I crush mine to flour with a corn mill and add rice hulls if needed.