Stirring the mash with a herms system?

[Wolfman]

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

Cheers mate will adjust before next brew day.

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 was getting good efficiency when fly sparging and not stiring the mash. Gone back to batch sparging, little less time consuming, and maybe this is where some of the hit has come from? Next time will try with a spilt sparge and a no stir with a 10 min recirc at 75c on both sparges.

Kev i'd be interested to hear the results if you brew before me next.

 

[Parks]

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.

I've found the crush to make a big difference in my efficiency. My last few brews have been back down under 70% (from close to 80%) and I realised that I hadn't checked the gap on mill...

It had slipped from 0.9 to 1.3mm.

The grain still looked crushed enough, but obviously that in combination with my system made a big difference.

 

[mckenry]

Just to add my 2c
Truman,
Can you underlet?
I also only sir at mash in, never again.
When I do my sparge, I underlet. This raises the grain bed again, I recirc for a few minutes til I see clear wort into the wort return dish, then off to the kettle.
Underletting is great. My eff is just shy of 90 and never a stuck sparge and the clarity into the kettle is great. Not that that is the be all and end all.

I tried stirring during the mash, at ramps etc like you do / propose, but all that changed was I had to recirc for much longer to get clear wort.

I run my pump the entire time, so the wort is going through the grain bed for a long time. both from top to bottom, then bottom to top (sparge) then top to bottom (recirc) then off to kettle.

This keeps my grain bed set, but not compact. I also mash in at 3L/kg

 

[dago001]

Wouldnt a refrac test prior to stirring and after stirring/recirc tell you if there is a noticeable gain to be had. I have tried stirring the mash at mash out, as I thought that it may help increase efficiency. I never noticed any difference, so didnt bother after that. Not inclined to bother again either. I mash fairly thin around 3.5/1 depending on the brew size, and always find that at the end of the sparge, I am getting a 1010ish reading, so I figure I have extracted all that I can. There may be entrapped sugars in the mash, but as I am getting an efficiency of 75%, they can stay in the mash. I have never really bothered trying to increase my efficiency, as I know what my system will output consistently. You may never reach 80% efficiency with your system.
I am more concerned about producing a beer that is not only of good quality, but will give me the exact same result every time I brew. Too much emphasis on the maths. Spend more time refining your system and techniques.
I built a herms system to simplify my brewing, granted the system is more complicated, but the actual procedure is pretty straigthforward. If I wanted to stir the mash more than once, I would go back to BIAB. No need to overcomplicate a simple system.
2c
Cheers
LagerBomb

 

[Truman42]

Just to add my 2c
Truman,
Can you underlet?
I also only sir at mash in, never again.
When I do my sparge, I underlet. This raises the grain bed again, I recirc for a few minutes til I see clear wort into the wort return dish, then off to the kettle.
Underletting is great. My eff is just shy of 90 and never a stuck sparge and the clarity into the kettle is great. Not that that is the be all and end all.

I tried stirring during the mash, at ramps etc like you do / propose, but all that changed was I had to recirc for much longer to get clear wort.

I run my pump the entire time, so the wort is going through the grain bed for a long time. both from top to bottom, then bottom to top (sparge) then top to bottom (recirc) then off to kettle.

This keeps my grain bed set, but not compact. I also mash in at 3L/kg

Yes I could underlet as my HLT is higher than my MLT so gravity should allow me to run the sparge water down and into the MLT outlet tap at the botom of the mash tun. Will certainly be giving this a go the next time to see if it improves my efficiency.

 

[GalBrew]

Just to add my 2c
Truman,
Can you underlet?

Out of curiosity (not the most experienced with sparging as I BIAB) is underletting an efficient way to rinse the grains? I am assuming that is a batch sparge? Does it effectively rinse the whole grain bed or do you get an inverse channelling thing going on?

 

[Wolfman]

Just to add my 2c
Truman,
Can you underlet?
I also only sir at mash in, never again.
When I do my sparge, I underlet. This raises the grain bed again, I recirc for a few minutes til I see clear wort into the wort return dish, then off to the kettle.
Underletting is great. My eff is just shy of 90 and never a stuck sparge and the clarity into the kettle is great. Not that that is the be all and end all.

I tried stirring during the mash, at ramps etc like you do / propose, but all that changed was I had to recirc for much longer to get clear wort.

I run my pump the entire time, so the wort is going through the grain bed for a long time. both from top to bottom, then bottom to top (sparge) then top to bottom (recirc) then off to kettle.

This keeps my grain bed set, but not compact. I also mash in at 3L/kg

Does this upset/change the grain bed? Do you add all the sparge water at once? How are you recircing your mash?

I can underlet as I have a LBP on my HLT, so will also try this. I think the way the wort is returned to the mash tun may also hold the key. I have tried a laidle with the hose conected, very complicated. Now just sit the silicon hose on top and this creates a whirlpool effect.

Whats peoples thoughts on this?

 

[mckenry]

Out of curiosity (not the most experienced with sparging as I BIAB) is underletting an efficient way to rinse the grains? I am assuming that is a batch sparge? Does it effectively rinse the whole grain bed or do you get an inverse channelling thing going on?

Yes mate. Channelling occurs when the liquid runs in one direction (down, with gravity as it will find the path of least resistance) all the time. So underletting means you cant channel the grain bed as gravity forces the liquid to flatten out as it rises, therefore soaking the entire grain bed, rinsing all the grain.

 

[mckenry]

Does this upset/change the grain bed? Do you add all the sparge water at once? How are you recircing your mash?

I can underlet as I have a LBP on my HLT, so will also try this. I think the way the wort is returned to the mash tun may also hold the key. I have tried a laidle with the hose conected, very complicated. Now just sit the silicon hose on top and this creates a whirlpool effect.

Whats peoples thoughts on this?

Quite the opposite of upsetting it. The grain is gently lifted with the liquid pouring in from underneath which 'loosens' it without disturbing it.
No, I sparge in two even goes, but only due to the size of my MT. Its 50L and I need 72L preboil
I have a HERMS so constantly recirculating, with a beerbelly return dish. I set the dish so the top of it is at the top of the grain. Wort comes into the dish then flows out over the flat grain bed and distributes evenly.
whirlpool is not ideal, you want it slower than that, but its probably better than a waterfall in the one spot as thats the kind of thing that leads to channelling. Get a wort return dish or go ghetto and just punch heaps of holes into a big coffee tin lid or similar.

 

[dago001]

Thought I would revisit the stirring of the mash routine and take a few refrac readings at the same time. At the end of the mash out I took a refrac reading which was 1069, as I expected it to be. Gave the mash a good stir and let it settle for a minute then took another refrac reading. Initial reading jumped to 1072. Let it recirc for 5 minutes took another reading - 1070. It took about 10 minutes before I was happy with the clarity of the wort, took another reading 1069. Not too sure what this proves and where the initial jump in gravity came from, but the final result for me was 46 litres into the boil at 1048, exactly what my recipe said it would be, at the efficiency it said it would be.
So the conclusion for me is that I have wasted about 15 minutes time to prove what i already knew. I would be interested if anybody else has came up with a different result to me.
Theres nothing wrong with chasing better efficiency, but for me, Im happy not to bother with stirring again. I know what my system is capable of, but that changes whenever I do a modification. I have just purchased a new mill, replacing my much loved home made mill. I will be interested to see what that does to my brewing results
Cheers
LagerBomb

 

[Truman42]

Interesting conclusion lagerbomb. Your tests would conclude that stirring seems to be a waste of time.

@mcKenry..So when you underlet do you also bother to give the mash a stir after youve added your sparge water? Or do you just underlet your sparge water, recirc for a few minutes until the wort runs clear then transfer to the kettle and repeat for the 2nd batch sparge?

 

[Screwtop]

Once we reach a good/happy point in our brewing process, most brewers then begin to look at ways to shave off some time or make the day easier while maintaining efficiency, so our processes change over time.

Thought I might relate some changes to my process.

Underletting:
Found that due to temp losses involved (HLT and lots of other SS stuff) I needed to underlet at a high strike temp to achieve sacch rest temp. The high conversion rate of some malts meant the resulting wort was more dextrinous (complex sugars) than planned and resulted in lower attenuation. So I moved to underletting for a Protien Rest which meant lower strike temp and attenuation went back up.

To save time: Used to wait until total brewing liquor in HLT had reached strike temp - Now strike water is underlet to the EMPTY MLT once the temp has reached about 50C, the remainder continues to heat to Mash Out temp in the HLT. Recirculation is begun using the HERMS HEX and in about 15 min strike water/MLT and all plumbing etc has attemporated at mash temp (Sacch Rest Temp, dropped Protien Rest). About half of the grist is added and given a gentle stir to mix, remainder is added and again a few turns using the mash paddle, temp drops 5 or 6 degrees. Takes about 10 min of recirculation for the mash to be back at the Sacch Rest temp and the mash timer is set.

Sparging: Have always preferred fly/continuous sparge as I'm lazy. Preboil volumes had never been an issue and were always spot on, however preboil gravity was usually a little above target. For each successive batch the brewhouse eff% would be increased in Beersmith, but preboil gravity would always be a little above target until I got to 92%.

By then my beers were suffering from astringency. PH is adjusted using brewing salts and tests showed sparge PH was not the cause. Sparge temp was dropped to 76C but astringency remained. Thought about dropping back the eff% in beersmith, but this would screw up volumes and gravity targets. Emailed some other brewers for their opinions, some advised to reduce sparge volume which made sense but how could I do that and maintain volumes?? Take some of your sparge water out prior to sparging and add it to the kettle was the answer. Tried removing 6 litres (double batch) of sparge water prior to sparging and adding it to the kettle, surprise - preboil volume and gravity was spot on, wow! even though 6 litres of water has not travelled through the grist. Astringency was all but gone from this batch. For the most recent batch 10 litres of sparge water was dropped straight to the kettle before sparge began. Again gravities and targets were spot on, no astringency detectable and maltiness has returned. Obviously the extra sparge water was removing nothing more from the grist other than tannins from the husks. Obviously sugars were fully rinsed from the grist as preboil gravity has been maintained.

Truman, I believe your eff% should be higher as others have said, maybe it's in the calculation. Like others I have not found a great difference in grind gap settings, only a few foints in eff%.

Hope this helps others.

Screwy

 

[mckenry]

Interesting conclusion lagerbomb. Your tests would conclude that stirring seems to be a waste of time.

@mcKenry..So when you underlet do you also bother to give the mash a stir after youve added your sparge water? Or do you just underlet your sparge water, recirc for a few minutes until the wort runs clear then transfer to the kettle and repeat for the 2nd batch sparge?

No stirring. I just stir at mash in, then thats it.