Mash Tun Cooler Question

[tomluter]

Hi Guys! I suppose I should start by introducing myself first, I'm Tom, I''m 22 and I've been brewing only for around 8 months but have loved beer since I was allowed to drink. I've done a few nice all grain brewings on the kit I initially set up (a BIAB keggle) but I've been investing a little more money recently and have now assembled myself a 3 tun set up, with pump, whirlpool ports, camlock connectors etc..
So, I did my first brew on the 3 tun set up around 3 weeks ago, a chocolate milk stout recipe of my own creation. The beer itself turned out very drinkable and is currently sat in my corny keg ready for me to drink whenever. That being said.. I did not hit anywhere near the OG or FG intended, and the beer only ended up being around 2.8% ABV (4.6% was intended). Intended OG was 1.056 and I got 1.042.
I also did a brew of a NEIPA two days ago, intended OG was also 1.056 and I got an OG of 1.042 again but the other issue was.. I got only 14L in the fermenter on this brew whereas I got 24L from the milk stout.

Grain bills on both recipes were similar (5.8KG and 6.2KG respectively) but the hop bill on the NEIPA was considerably higher than the stout, but surely that shouldnt be enough to lose 10L?

The mash tun i'm using is a converter 42LTR cooler with bazooka filter as the "false bottom", could the gravitity issue be caused by this? Should I invest in a proper full false bottom?

I am pumping my wort to the kettle via the tap and pump, when the pump sounds like it is running dry I stop pumping, would it be worthwhile to pump until in sounds dry, then allow the water to settle to the bottom and then try pumping again? (In case I'm missing a certain amount of water from the grains)

I appreciate all your help, the forum looks great and I hope to be active on this forum as I am on other forums.

Thanks guys!

 

[cushyno]

Hi, are you pumping the wort into your kettle straight after mash, or lautering and sparging first?

 

[lancon]

If this happened to me then the questions that arise in my mind are, have I checked hydrometer/temperature, did I take a gravity reading of first runnings, am I sparging efficiently, have I tried iodine test? Also as a matter of interest is the mash tun a bit big for that amount of grain? could there be a problem with the grain bed being too shallow not holding the temperature?

 

[tomluter]

Hi, are you pumping the wort into your kettle straight after mash, or lautering and sparging first?

I am vorlaufinf, then pumping straight from tun to kettle, then batch sparging, leaving for 15 minutes and then pumping the rest over.

 

[tomluter]

If this happened to me then the questions that arise in my mind are, have I checked hydrometer/temperature, did I take a gravity reading of first runnings, am I sparging efficiently, have I tried iodine test? Also as a matter of interest is the mash tun a bit big for that amount of grain? could there be a problem with the grain bed being too shallow not holding the temperature?

All sound like good ideas. Perhaps it may be time for a new hydrometer or an upgrade. I will look into iodine testing to make sure all my sugars are being extracted properly.
Can I ask what is meant by sparging efficiently? I’d love to know how I could sparge better if you’ve got any tips?

Regarding the last point, the tun is slightly larger than necessary. 6KG of grain and then I use 20 LTR initial strike water plus around 16/17 LTR sparge water so it’s never full to the top. Perhaps I need to check the temperature more often in the tun to make sure I’m not dropping too low.

 

[lancon]

I just had a look at Beersmith, (are you using software for recipe) I think you should be using less strike water and then probably the sparge in 2 or 3 stages. Personally I would run the mash tun to a vessel and then pump from there.

 

[tomluter]

I just had a look at Beersmith, (are you using software for recipe) I think you should be using less strike water and then probably the sparge in 2 or 3 stages. Personally I would run the mash tun to a vessel and then pump from there.

I use Brewers Friend to make my recipes. Does beer smith say how much sparge water I should use?

So you think perhaps sparge in 2 batches and then transfer to an in between vessel and then pump to kettle from there? I could certainly do that.

 

[simon12]

Could it be you just have alot of dead space in the equipment so your loosing alot in the bottom of the vessels and the pump tubing etc? Otherwise for efficiency that bad could the grain be off? Do you even need a pump for that batch size ie could you drain the mash tun into a bucket and just pour it into the kettle, not that this is likely the issue. I had a similar plastic setup and was getting efficiency in the mid 70%s with a 2 stage batch sparge.

 

[Baffled]

What grain are you using? Is it bought already crushed or are you crushing it yourself?

 

[tomluter]

Could it be you just have alot of dead space in the equipment so your loosing alot in the bottom of the vessels and the pump tubing etc? Otherwise for efficiency that bad could the grain be off? Do you even need a pump for that batch size ie could you drain the mash tun into a bucket and just pour it into the kettle, not that this is likely the issue. I had a similar plastic setup and was getting efficiency in the mid 70%s with a 2 stage batch sparge.

Dead space isn't huge, I already take that into consideration in my calculations. I think maybe next brew I'll eliminate the pump and just transfer using tap to intermediate vessel and then pop that into the kettle.
Grain wise.. I get it from The Malt Miller and order as and when I need it (I input my recipes and they send the exact quantity I need)

 

[tomluter]

What grain are you using? Is it bought already crushed or are you crushing it yourself?

Store crushed, straight from The Malt Miller.

 

[lancon]

The reason I suggested eliminating the pump was in case it caused the sparging to run too quick. What is your target batch size and I'll run it through BeerSmith

 

[tomluter]

The reason I suggested eliminating the pump was in case it caused the sparging to run too quick. What is your target batch size and I'll run it through BeerSmith

Much appreciated, heres the whole recipe, and you can see my last brew session too.

Let me know if you spot anything worth changing?

 

[lancon]

Well I couldn't put exact grains in and my yeast profiles need updating. The temperatures are interesting, what temperature water do you add? If you add 66C water to the initial mash then it cools down, I use 73C water which then cools down in heating up the grain....
If that's not the case then I would go for a simple recipe and measure SG of initial runnings and then regular SG readings of the sparge.
Just looking back I see that your milk stout was 2.8%, with 1.042 this means ending on 1.020/1. It is not something as easy correcting your SG with temperature of wort?

 

[tomluter]

View attachment 17178
Well I couldn't put exact grains in and my yeast profiles need updating. The temperatures are interesting, what temperature water do you add? If you add 66C water to the initial mash then it cools down, I use 73C water which then cools down in heating up the grain....
If that's not the case then I would go for a simple recipe and measure SG of initial runnings and then regular SG readings of the sparge.
Just looking back I see that your milk stout was 2.8%, with 1.042 this means ending on 1.020/1. It is not something as easy correcting your SG with temperature of wort?

I have to say I only over heat by strike water by around 2-3 degrees, perhaps I should try to get it a bit higher to compensate for drops. I'll try 73C next brew.

I usually cool the water when I take OG readings, but I'm not 100% sure what my hydrometer is calibrated to. Do you think a refractometer could be more accurate than a hydrometer? I've been considering getting myself one.

 

[lancon]

UK Hydrometer normally calibrated to 20C. You heat the water and then add it to the mash tun (as opposed to a mash tun with an element). The iodine test is simple and shows that your mash is complete. Its a nuisance when a problem arises. Accurate (aka more expensive) hydrometer probably better then cheap refractometer and vice versa, I use Malt Millers hydrometer for everyday and an expensive (calibrated which is unnecessary for domestic brewing) hydrometer from Stevenson Reeves for final calculations along with an Index Instruments refractometer.

 

[Gerryjo]

If this happened to me then the questions that arise in my mind are, have I checked hydrometer/temperature, did I take a gravity reading of first runnings, am I sparging efficiently, have I tried iodine test? Also as a matter of interest is the mash tun a bit big for that amount of grain? could there be a problem with the grain bed being too shallow not holding the temperature?

I use a 52 litre coolbox with a 12" bazooka and a 1/2" ball valve and shall either infusion mash or use 3l per 1kg of grain and reciculate through a burco cygnet.
I have no issues and use crushed grain and still get around 70% efficiency.
It has been insulated and retains heat with a loss of only 1-2 degrees if I only infusion mash.
I would make sure that the grains are soaked for at least 20 mins and well mixed before recirculating as well as the other points highlighted though it will take a few brews to calibrate.

 

[tomluter]

I’ve considered adding a recirculating port to the mash tun, sort of like a shower to spread it evenly across the bed. Would that increase efficiency?

 

[Gerryjo]

Lots of people use various methods for recirculation and yes it may help to aid your efficiency.I use a simple garden fountain pump which cost £5 from eBay which I pump from the mashtun to my boiler to regulate the sort temperature and gravity fees back from the boiler to the mashtun which is regulated using the levers on the ball valves.
Best ever efficiency was 80% with fresh grains but usually average between 70/75%.

 

[lancon]

I've never recirculated a mash, I just put initial water in, then grain, then drain after 60mins, then add 20ish litres of water (76C normally) leave 15-30 minutes drain slowly, add more water repeat, always have water over the grain until draining, generally I seem to get 80% efficiency. I think that the first thing is to check your initial runnings SG