Stirring the mash with a herms system?

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Truman42

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Gday Gents,

I just want to run my mash procedures by you to see if Im doing it right or if I could improve on my current procedures. Im getting around 65-70% on average gravity brews of around 1.050 start gravity.

I use a 3V system with a herms coil

1. Heat water in HLT to strike temp and drain to mash tun (keg with domed stainless mesh false bottom)
2. Dough in at a ratio of around 3:1 adding half the grain, stirring then adding the rest and stirring again.
3. Start pump which recirculates through the herms coil and back to the mash tun and Im using a T piece on the end of my hose with a loop of hose that has slots cut into it as my mash return.
4. Raise the temp on my herms to ramp up to the next step as per the recipe. (pump runs for the entire mash)
5. Raise to 75C for 10 min mash out then transfer to kettle until pump runs dry.
6. Add half of my sparge water at a temp of 82C. Stir for a few minutes then recirculate for 10 mins.
7. Transfer to kettle then repeat for second batch sparge.
8. Begin boil.

Ive been reading about stirring the grain at least a couple of times during the mash but seems to be done only with non recirculating systems such as BIAB etc.

I was advised not to bother stirring as im recirculating my wort, which will allow the enymes to move through the grains and convert the starches. Although Ive never had a stuck sparge, Ive considered that this recirculation for 90 mins might be compacting the grain bed and causing the enzymes to be "locked" in place so to speak and not be able to freely move around in the mash.
Obviously when I sparge and give it a stir Im freeing this up but as Ive already done a mash out wouldn't I only be freeing up sugars already converted and thus ending up with a lot of starch that wasn't able to be converted by the enzymes?

So would a stir of the mash at regular intervals, (say each time I ramp up) be beneficial? Do other herms brewers here stir their mash at all? Have you noticed a difference in efficiency compared to if you havent stirred?

Yes I could do this in my next brew as an experiment but would like to know if others have done this and what their findings were.

If I did my last stirring while ramping up to a mash out step the ten minute mash out should be enough recirculation to filter the wort through the grain bed as it is during my sparge steps.

(Yes I searched and most posts related to stirring BIAB or non recirculation mash, didnt find anything on stirring a herms or rims mash)

Thanks in advance gents for those willing to offer some good helpful advice.
 
Truman, I do exactly the same as you, however, I stir after adding the first and second sparges. On my old system this used to give me about 80% efficiency, on the new, somewhat less due to the physical design of it. logially speaking you are using mehcanical action (stirring) to help rinse the sugars from the mash. If you are chasing better efficiency then do it as you only have to recirculate for a few minutes to get the wort flowing cleanly again.
 
Same here - only stir at dough in and at sparge.
I mash a bit thinner - 4l/kg and also am extra cautious not to compact the grain bed.
I let it sit for a good 10 minutes following dough in - this is normally just my first rest - then begin recirculation.

Compacted grain bed sounds like a separate issue to efficiency/stirring, though they are obviously related in their effects.

I can only speak for my setup/experience, but I feel that all the grain gets a mighty good washing through a 90 minute recirculation.
I normally hit 75% and that is all I'm after myself.

You might consider your crush as a factor as well.

Having said that, I don't see the 'harm' in stirring more, you just have to wait for your grainbed to resettle, or be mindful that you're more likely to cause it to compact when you pull the grain down from being in suspension with the pump.

To me, you're either stirring/agitating the grain, or your recirculating the liquor through it, both to the same end, but never both at the same time YMMV though.

65-70% sounds all right to me. I just CBF chasing efficiency points beyond 70%, grain is cheap, life is short ;-)
 
@browndog... I also stir between at the start of the first and second sparge? How long do you sparge for each time? 10 mins?

@hsb... I'd be happy with 70% but more often that not its around 65%. Would like to get that extra 5% consistently.
 
I only stir after I've gotten pretty close to mash out. Once I've given it a stir I leave it for at least 10min until the wort clears up fully. Then once all my batch sparge water is added I give it a second stir, and once again give it at least 10mins. So only 2 stirs for the entire brew. Most my beers are only 1.040 OG, but I get around 85% efficiency.

I don't stir upfront of the mash as I underlet the mash water, so dough balls are not an issue.

I think a big % of the efficiency comes from the crush and the sparge. Crush needs to be fine enough so not too much sugar is caught in the sparge, and the sparge needs a good stir to mix into suspension all the sugar.

If you are ramping up the main mash to mashout, why are you adding 82c sparge water? What temp does that settle at? To me since your grain bed is already at mashout temps, the sparge water should only need to be at the same temp.

QldKev
 
I would not recommend stirring truman, If you do you will disturb the grain bed. I only stir, as others have said, when I add the sparge water then rest again before recirc begins.
As for the eff. I get about 85-87% MASH efficiency (which is the important one imo) with a regular 55/65/78 step mash, one thing I noticed is your mashout is 75 so you may want to increase that a little. Not too much as you risk tannin extraction.

I think one of the other big impacts of mash efficiency (measured as 'into the boiler') along with crush and sparge as QldKev said is the mash tun loss! My mash tun pickup under my false bottom is extremely close to the bottom of the tun, I let it pump until I hear the suction from in the tun, then I take off my hose at the MT outlet and get all the liquid out of the herms line (by blowing on the other end of the hose) and pour that into the kettle through a sieve. That has reduced my loss alot and I believe helps for a good mash efficiency.
 
Gryphon Brewing said:
I stir once at mash/dough in thats it, I can get 82% effic but dumb it down to 76% so I dont get below 1.010 onmy last runnings.
Nev
I'm with him ....
I always get between 70 & 75%, fly sparge - never stirring.......
Cheers
BBB
 
I batch and stir at Dough-in and between each sparge,

I have thought (I like to play and something to do) about putting a "stirrer" in the tun to stir for the full mash
 
@browndog... I also stir between at the start of the first and second sparge? How long do you sparge for each time? 10 mins?
Right, I neglected to see that. If by sparge, you mean recirculate, then as soon as the wort is running clear it's into the kettle, no more than a couple of mins stirring and 5 mins or less of recirculating.
 
I think a big % of the efficiency comes from the crush and the sparge. Crush needs to be fine enough so not too much sugar is caught in the sparge, and the sparge needs a good stir to mix into suspension all the sugar.

If you are ramping up the main mash to mashout, why are you adding 82c sparge water? What temp does that settle at? To me since your grain bed is already at mashout temps, the sparge water should only need to be at the same temp.

Now that I have my own grain mill I can buy grains uncrushed and see how I go crushing my own instead of relying on the crush from the LHBS.

I add 82C sparge water as I lose a bit by the time I stir it etc. Its usually around 78C once I begin recirculation.

@ Acasta..My mash tun pick up is at the very bottom of my keg. (The keg is on legs so the outlet comes out under that so dead space in the mash tun is minimal. I do blow out the lines but dont usually collect the wort so might do that from now on.

How exactly do you measure mash efficiency into the kettle? Brewmate only has a brewhouse efficiency calculator. If I put in my figures say from my last recipe of SOB gravity 1.040 and volume of 37.5 litres it gives me 84%. Does that sound right? If so maybe Im doing better than I thought.
 
browndog said:
Right, I neglected to see that. If by sparge, you mean recirculate, then as soon as the wort is running clear it's into the kettle, no more than a couple of mins stirring and 5 mins or less of recirculating.
Ok so waiting 10 mins is pointless? Great, Always trying to knock off a few extra minutes of my brew day. Will try that next time, cheers.
 
Truman said:
How exactly do you measure mash efficiency into the kettle? Brewmate only has a brewhouse efficiency calculator. If I put in my figures say from my last recipe of SOB gravity 1.040 and volume of 37.5 litres it gives me 84%. Does that sound right? If so maybe Im doing better than I thought.
It depends on the grain bill, mash temp and length and the type of sparge you use, but assuming you have got your ducks in a row it doesn't sound like 84% is too far off. I get about 75% mash efficiency with single infusion and double batch sparge, but with HERMS you should do better than me.

I don't calculate my mash efficiency though, I let beer smith do it for me. So long as it is a consistent 70-75% I'm a happy brewer. Got more important things to worry about than chasing a few extra points of efficiency for the sake of it.

JD
 
So using beersmith I imported my last recipe and input the figures into the efficiency table and I still get 84% mash efficiency. So I can assume that my brewhouse efficiency is dropping possibly because my settings such as trub loss, evaporation rates etc need more tweaking.
i did notice that my usual evap rate of 15% is off as Im not losing that much and have since reset this to 12 % based on my last brew. But Ive also noticed that for my last few brews Ive always been around 5 points under at EOB.
Could this be because my evap loss was set too high?
 
Truman said:
So using beersmith I imported my last recipe and input the figures into the efficiency table and I still get 84% mash efficiency. So I can assume that my brewhouse efficiency is dropping possibly because my settings such as trub loss, evaporation rates etc need more tweaking.
i did notice that my usual evap rate of 15% is off as Im not losing that much and have since reset this to 12 % based on my last brew. But Ive also noticed that for my last few brews Ive always been around 5 points under at EOB.
Could this be because my evap loss was set too high?

In Beersmith it has a field where you can enter the volume, so even if you didn't get the desired vols it should equal the same efficiency.
 
I have also been struggling with efficiency. I was also wondering if it had to do with the crush. Though id experiment on the last brew day. So the first brew looked like the kernels were not crushed enough. About 65% on that brew. The second brew I though I would tighten the gap and double mill. What a mistake. Two stuck mashes! Pretty sure ill find out that hot side airation is real with this batch. Was a major **** up of a day which I won't fully go into.

So, my question is What is the best gape distance on your mill for a Herms brewery?
 
I'm with Nev and BBB. I stir at dough-in and don't touch it after that. I've only done recirc on my last few brews, but recirc or not, I hit around 80% efficiency.
 
Wolfman said:
I have also been struggling with efficiency. I was also wondering if it had to do with the crush. Though id experiment on the last brew day. So the first brew looked like the kernels were not crushed enough. About 65% on that brew. The second brew I though I would tighten the gap and double mill. What a mistake. Two stuck mashes! Pretty sure ill find out that hot side airation is real with this batch. Was a major **** up of a day which I won't fully go into.

So, my question is What is the best gape distance on your mill for a Herms brewery?
Cant give you a size but if you crush so the grain is still 50% intact and when you rub it between your hands it falls apart you are pretty much on track.
Efficiency will grow as the flow thru the grain beds increases.
Nev
 
I may give the next brew a no stir approach and see how the efficiency compares. Maybe I'm just wasting my time waiting for it to clear up after stirring it.
 
I've been trying to get my efficiency up on my new rig and noticed that my crush (due to lack of maintenance on my home made mill) had a lot of whole grains in it. While the grains did break up when rubbed, I decided to run it through the mill a second time and see how that effected efficiency. After the second time through there were no more whole grains to be seen and I was a bit worried I was going to be in for a stuck sparge. So the result, no difference in efficiency at all.
 

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