HERMS question

[BoozeMedic]

Just a FNG who is in the dream stages of an eventual electric brewery.

So... if I'm recirculating wort from my MLT through a coil in the only slightly hotter HLT... how do I sparge?
For instance: If my MLT is 152°F and my HLT is, say, 153°F or 154°F, using a constant recirc, where does my 170°F sparge water come from? A second HLT?

Also, how do I prevent a stuck recirc?

I'm sure I'm overthinking something somewhere.

 

[SoCal-Doug]

Even this FOG was a FNG once, and you asked a great question for noobs just starting out with recirculating all grain systems.

After you are done mashing, you will bring your hlt up to about 170-172 so your mash gets to roughly 168. This "mash out" serves a few purposes. It makes the sugars more soluble and denatures the enzymes. In general it gets the grain ready to be rinsed clean of the goodness we need.

Now that your wort is around 168 and your hlt is around 170, close the valve that brings wort into your pump and open the valve that drains hlt water into your pump or mash tun. begin draining your mash tun into the boil kettle slowly. adjust the sparge flow to match (fiddle as needed). There are many ways to accomplish this. Valves, quick disconnects, altitude, bucket, or whatever you dream up and build.

In theory, you could sparge with 152F water although not as efficient. A typical 3 vessel herms system however, will do a mashout then sparge with water at around 170.

Hope this helps

 

[doug293cz]

... It makes the sugars more soluble ...

This is a common misconception. All of the sugar is dissolved in the wort as it is created. There is never any solid sugar to dissolve. The solubility of maltose in water at mash temps is 67% by weight, or two lb of maltose in one lb of water. This corresponds to an SG of around 1.300 (you can't possibly get the wort SG in a mash this high.) You never have to worry about sugar solubility in the mash. The increased temperature will drop the viscosity of the wort by about 19%, but the dilution by sparge water will decrease it very much more, so the viscosity drop is not really a big deal, since sparge time is limited by the flow rate needed to prevent channeling.

So, the primary benefit of mash out is to denature the enzymes, so that the non-fermentable sugars don't continue to become more fermentable during the long sparge time. If wort is too fermentable, you can have thinner/dryer beer than you desire.

The secondary benefit is that if your conversion is not complete at the end of the allotted mash time, then the higher temps, plus extra time before all of the enzymes are denatured, will supercharge your conversion for a short time, and improve your conversion efficiency and mash efficiency. If your conversion is complete at the end of the mash time, then this effect is not observed.

Brew on

 

[Smellyglove]

And if you want to avoid have to clean the coil after the session you just sparge through the coil to rise it.

 

[augiedoggy]

Even this FOG was a FNG once, and you asked a great question for noobs just starting out with recirculating all grain systems.

After you are done mashing, you will bring your hlt up to about 170-172 so your mash gets to roughly 168. This "mash out" serves a few purposes. It makes the sugars more soluble and denatures the enzymes. In general it gets the grain ready to be rinsed clean of the goodness we need.

Now that your wort is around 168 and your hlt is around 170, close the valve that brings wort into your pump and open the valve that drains hlt water into your pump or mash tun. begin draining your mash tun into the boil kettle slowly. adjust the sparge flow to match (fiddle as needed). There are many ways to accomplish this. Valves, quick disconnects, altitude, bucket, or whatever you dream up and build.

In theory, you could sparge with 152F water although not as efficient. A typical 3 vessel herms system however, will do a mashout then sparge with water at around 170.

Hope this helps

I second this.
I skipped this "mashout" step for years with my rims setup and found I got a nice boost in efficiency when I started taking the time to do it... some of it may have been from the longer mash time (I mash for 60 minutes) though I do believe the actual slow rising of the mash temp was more the reason since I experimented with longer mash sessions and never got the consistent boost I get from the mashout. (efficiency went from 88% to 91 with just that and a slower sparge session and has consistently averaged about 91% since.) Well worth the extra 12 minutes or so for mashout and extra 10-15 minutes I spend on sparging.

 

[Smellyglove]

I second this.
I skipped this "mashout" step for years with my rims setup and found I got a nice boost in efficiency when I started taking the time to do it... some of it may have been from the longer mash time though I do believe the actual slow rising of the mash temp was more the reason.

It's mostly due to the higher gelatinization temps of some of the starch granules in the malt. If you skip the step you don't gelatinize a part of the starch, thus not being able to convert them since they are not soluble below gelatinization temps.

 

[doug293cz]

It's mostly due to the higher gelatinization temps of some of the starch granules in the malt. If you skip the step you don't gelatinize a part of the starch, thus not being able to convert them since they are not soluble below gelatinization temps.

Gelatinization temp is also affected by the type, source and vintage of the grains. I have seen reports that some recent European barley vintages have a higher than usual gelatinization temp. But like most things temperature related (the exceptions being boiling points and freezing points) they do not happen at a fixed temperature, but rather over a range of temperatures. And they happen more slowly at lower temps than higher temps. That is one reason that finer crush can give you higher conversion efficiency. The water gets to the inner starch granules quicker (since they are closer to the surface of the grits) and the water has more time to work on the gelatinization at the lower temps.

Lack of complete gelatinization is one cause of incomplete conversion, and mash-out can mitigate that. But the fact remains that if conversion is complete, then mash out will not increase efficiency.

Brew on

 

[Smellyglove]

Gelatinization temp is also affected by the type, source and vintage of the grains. I have seen reports that some recent European barley vintages have a higher than usual gelatinization temp. But like most things temperature related (the exceptions being boiling points and freezing points) they do not happen at a fixed temperature, but rather over a range of temperatures. And they happen more slowly at lower temps than higher temps. That is one reason that finer crush can give you higher conversion efficiency. The water gets to the inner starch granules quicker (since they are closer to the surface of the grits) and the water has more time to work on the gelatinization at the lower temps.

Lack of complete gelatinization is one cause of incomplete conversion, and mash-out can mitigate that. But the fact remains that if conversion is complete, then mash out will not increase efficiency.

Brew on

You are absolutely correct. But if you mash at 65C, which is a classic temperature for fermentability, you still have undissolved starches left which will not become soluble until 70-75C, 72C is a normal temperature for the dextrinisation step. Even if you hold the step for an extended time, but it might be not long enough to get those small granules to solute.

Gelatinization is dependent on the crop mostly, and what kind of grains, as the process in the malthouse is mostly the same but with some variations to accommodate the differences in the grains itself.

 

[SoCal-Doug]

now after all this, I wonder if the o/p actually got an answer to his question

 

[AkTom]

Shiny!!! Wait, what?

 

[GoeHaarden]

This is a common misconception. All of the sugar is dissolved in the wort as it is created. There is never any solid sugar to dissolve. The solubility of maltose in water at mash temps is 67% by weight, or two lb of maltose in one lb of water. This corresponds to an SG of around 1.300 (you can't possibly get the wort SG in a mash this high.) You never have to worry about sugar solubility in the mash. The increased temperature will drop the viscosity of the wort by about 19%, but the dilution by sparge water will decrease it very much more, so the viscosity drop is not really a big deal, since sparge time is limited by the flow rate needed to prevent channeling.

So, the primary benefit of mash out is to denature the enzymes, so that the non-fermentable sugars don't continue to become more fermentable during the long sparge time. If wort is too fermentable, you can have thinner/dryer beer than you desire.

The secondary benefit is that if your conversion is not complete at the end of the allotted mash time, then the higher temps, plus extra time before all of the enzymes are denatured, will supercharge your conversion for a short time, and improve your conversion efficiency and mash efficiency. If your conversion is complete at the end of the mash time, then this effect is not observed.

Brew on

 

[SoCal-Doug]

LOL

I never mentioned dissolving anything

 

[doug293cz]

LOL

I never mentioned dissolving anything

Increasing solubility ("makes the sugars more soluble") is usually used in the context of getting more of something to dissolve. It's true that you could dissolve more sugar in the wort at higher temperatures, but that is moot, since you are nowhere near the solubility limit to start with. Dissolving things faster, which higher temps enable, is also moot, since all the sugar is created in solution.

Brew on

 

[Gameface]

Just a FNG who is in the dream stages of an eventual electric brewery.

So... if I'm recirculating wort from my MLT through a coil in the only slightly hotter HLT... how do I sparge?
For instance: If my MLT is 152°F and my HLT is, say, 153°F or 154°F, using a constant recirc, where does my 170°F sparge water come from? A second HLT?

Also, how do I prevent a stuck recirc?

I'm sure I'm overthinking something somewhere.

I'll take on the stuck recirc bit...

First line of defense is rice hulls.

Second line of defense is larger gap on your mill. Don't do this unless you have to because it does usually affect your efficiency. Try more rice hulls first.

But there are also some finer points. I usually dough in then wait a minute or two before starting recirc. When I do start recirc I start slow, then wait, then open the valve a very little bit more, then wait, then a little more, wait, more, wait, more, wait, more, wait, open all the way.

Helps the grain to settle and flow to become established before slamming the grain bed with pull from the pump.

I've done a mash out and I've not done a mash out. I haven't done a controlled experiment to compare the two, but it isn't something I consider even remotely critical. I'm not usually trying to control body or fermentability via the mash, I do that via the recipe and go for as much fermentability as I can get out of the mash.

 

[augiedoggy]

I can also offer an opinion on the stuck sparge based on what I do. which seems to be a bit different from gamefaces approach but does work well for me.

I never use rice hulls, never needed them. Tried them once and saw no difference. (I rarely do wheat beers and when I do theres not a lot in the grist, if I did I would use the rice)

I set my mill gap at 1.030 with credit card. (ive never "conditioned" my grain.)

I do have a cheap bayou classic kettle and fb for MT but I use a length of 30" fine stainless braid like you would find on the outside of a dishwasher or toliet water line attached to my diptube underneath as a second chance filter to stop the grain that gets through the FB from plugging the small 24v pumps I use.

I recirculate at 1.5- 1.8gpm depending of resistance of grainbed against the pump but 95% or the time its in that range. (I have a cheap flowmeter which shows speed/volume) I start out the flow speed of the pump at about 1gpm like gameface suggests. I leave it there for at least a few minutes before increasing speed so the grainbed "sets" I then dont mess with stirring the grain bed at all since I do not get channeling with the low flow speed like many with big 7gpm pumps do when they try to throttle them down with a ballvale (and likely still try pulling 3-4gpm) IMO this creates more problems with no benefit.

in over 5 years the only time Ive ever had a stuck sparge/recirc was when I forgot to attach the braided line under my FB I have had a scarce few (oats and wheat) that ran slow (under 1gpm) and could have benefited from rice hulls im sure but everything still worked out ok.

 

[cruelkix]

Just a FNG who is in the dream stages of an eventual electric brewery.

So... if I'm recirculating wort from my MLT through a coil in the only slightly hotter HLT... how do I sparge?
For instance: If my MLT is 152°F and my HLT is, say, 153°F or 154°F, using a constant recirc, where does my 170°F sparge water come from? A second HLT?

Also, how do I prevent a stuck recirc?

I'm sure I'm overthinking something somewhere.

Good question. What I would do is just start to bump your temp up like 10 minutes before the end of your mash. You won't loss too much heat form your MLT in that time and you will then have time to raise your water from the 154 recirc temp to the 170 you want for your sparge. Just remember to stop the recirc or it will be hard for you HLT to increase in temp. Also, you may need to set your HLT higher than 154 to keep your MLT at 152. It depends on your heat loss from hoses, kettle, etc as well as the flow rate of the recirc. You may want to monitor your herms outlet temp to make sure you dont get too high tho. HTH.