Suggestions to improve my all grain kit, getting variations in mash temps (hot spots)

[pyrocam]

Hi all, what I am hoping to get is some changes in my process or suggestions for things I can change in my kit to get around the issues I am finding.

So, I have been slowly building up a piece of kit for my all grain, but I am getting a high F.G. so I think it has some short comings when managing the mashing temps, specifically I think I am getting big variations within the grain bed.

I built this to be mostly self contained and using trying to use vertical space rather than a sprawling bench top. I have a frame to hold a big 50L (13Ga) pot over a 3 ring LPG burner. Inside this pot is also a 2000w element to help maintain and adjust temperature while mashing, and some stainless legs. to hold up an inner 40L (10Gal) pot with a false mesh bottom.

The mashing plan:
use LPG to get the water up to strike temp, add grains, make sure the water is an inch or more over the grain bed, then use the STC1000 to manage the temperature while continuous/fly sparging.

Once I have finished mashing I can raise (using a winch) the inner pot up out of the big pot and sparge with some new kettle water

Let that sit for a while to drain then start the boil using the 3 ring burner.

I only have pictures of me testing the setup but they might help make sense of it.

I have tried moving the temperature probe around and I feel like I get the best results when its in the wort rather than the grain bed, but even when placing the probe in different places I am getting heaps of variation in the bed.

Any thoughts would be appreciated. Thanks in advance

 

[cswis86]

So you're continually circulating the mash with your pump right? I would think you should be getting really even temps. The temp of the grain bed doesn't really matter during the mash. The liquid wort is where the enzymes and starches are so that's the temp you should focus on. In my experience, high FG is 90% of the time a problem with fermentation/yeast health so maybe it's worth reviewing your fermentation process as well.

Also, that's a pretty nice setup! I'm still mashing in a cooler

 

[pyrocam]

So you're continually circulating the mash with your pump right? I would think you should be getting really even temps.

Thanks! that's what I would of thought too, it is pretty much the basis of this design

I have to fiddle with the valves to match the flow a bit, but generally speaking its continuous albeit quite slow, slower than I would like sometimes.

The temp of the grain bed doesn't really matter during the mash. The liquid wort is where the enzymes and starches are so that's the temp you should focus on.

interesting, I will try and mount the temperature probe further into the dead space under the inner pot, I might get a better read (and therefore adjustment) there. I just have to be cautious of the element and junk

In my experience, high FG is 90% of the time a problem with fermentation/yeast health so maybe it's worth reviewing your fermentation process as well.

Valid point, I use Safale 05 most of the time, and I dry pitch ( based on comments that you dont need a starter with those packs.) and use the STC1000 in an old refrigerator, I usually aim for 18-19 degrees C (64.4f) I posted my last 3 batches below , I'm using really basic grains as I am just trying to get the kit working well with super basic brews right now.

Also, that's a pretty nice setup! I'm still mashing in a cooler

thanks!

Edit. re-reading the dry pitching threads and maybe I am wrong and I should be at least re-hydrating .... whoops
Edit2. http://www.fermentis.com/wp-content/uploads/2016/12/SafAle-US-053.pdf Oh. ok . well. Looks like you might be right

 

[jekeane]

so is that how your return works while mashing? Like are you just flowing wort down from that height with no dispersion etc? If so I have to imagine that you are just blasting a hole through your grain bed and there is no dispersion or filtering going on except in the "blast radius". I'm not sure how much I believe in hot side aeration but if that image is now you are running your wort then that would be the ideal setup for hot side aeration to be put to the test. I think the LODO guys may have a heart attack looking at that!

Would running a piece of silicone hose with a sparge arm head like this one on it be a better idea? https://www.amazon.com/dp/B00X39TRE0/?tag=skimlinks_replacement-20

 

[acidrain]

Nice setup.
I would add a valve to the exit side of the pump, and add some kind of dispersion for the wort return. Even aluminum foil with holes punched in it.
Then you can open the tun outlet fully as you have there, and throttle down the flow a bit.
If you're not getting stuck sparge running wide open like that, your crush may be too coarse.

All that aside from your issue. I would look at cell count for sure.
Something to consider (related to above comments) is your temp probe placement.
Like cswis86 said... monitor your temp at the wort. I monitor at the pump outlet at about 2 deg F above target temp to allow for the small temp drop that happens after routing through hoses.

 

[pyrocam]

so is that how your return works while mashing? Like are you just flowing wort down from that height with no dispersion etc? ...

Would running a piece of silicone hose with a sparge arm head like this one on it be a better idea? https://www.amazon.com/dp/B00X39TRE0/?tag=skimlinks_replacement-20

You are not wrong, in fact I have looked at that exact product, I'm halfway there, I should of probably mentioned: I just bought 2 meters of silicone to replace that most of that copper pipe (conveniently sent to me as 2x 1M lengths of Silicone, thanks Ebay) Although when I was using it the flow rate was quite low. Definitely not as fast as shown, that was me testing the setup.

I have looked at the Fighter but its really expensive and hard to to get to NZ. I haven't tested this yet but I'm planing on just cutting out notches in a length of silicone hose and coiling it in the pot, I also have some 2.5mm perforated stainless I was considering making a 'grain lid' type thing. although I haven't seen anyone else use that before.

Nice setup.
I would add a valve to the exit side of the pump, and add some kind of dispersion for the wort return. Even aluminum foil with holes punched in it.
Then you can open the tun outlet fully as you have there, and throttle down the flow a bit.

Ooops sorry, it has that aswell now, in the picture you only see one but I have the same ball valve on the output as well now. that's what I use to control the flow. I would also like to consider a float switch triggering the pump so I can maintain a specific liquor/wort position.

If you're not getting stuck sparge running wide open like that, your crush may be too coarse.

I am not sure what you mean by that sorry? can you rephrase? it sounds like something else I might be having an issue with (managing flow rate)

All that aside from your issue. I would look at cell count for sure.
Something to consider (related to above comments) is your temp probe placement.
Like cswis86 said... monitor your temp at the wort. I monitor at the pump outlet at about 2 deg F above target temp to allow for the small temp drop that happens after routing through hoses.

Cool, thanks will try both



All these nice comments, making me think I should post some actually nice photos without bare feet in them.

 

[acidrain]

I said stuck sparge, but I should have said stuck vorlauf, or stuck re-circulation. It's really all the same thing happening at different phases of the mash.
Stuck "anything" happens when you drain too fast and the grain packs down and blocks the flow.
The goal is to crush the grain as fine as you can (crushed so the hulls are intact, but the center is fairly pulverized) and circulate slow enough that you don't get stuck.
If you slow the flow, it helps avoid packing down the grain.
If you flow very fast, and you never get stuck, your crush may be too coarse.

 

[pyrocam]

I said stuck sparge, but I should have said stuck vorlauf, or stuck re-circulation. It's really all the same thing happening at different phases of the mash.
Stuck "anything" happens when you drain too fast and the grain packs down and blocks the flow.
The goal is to crush the grain as fine as you can (crushed so the hulls are intact, but the center is fairly pulverized) and circulate slow enough that you don't get stuck.
If you slow the flow, it helps avoid packing down the grain.
If you flow very fast, and you never get stuck, your crush may be too coarse.

I didn't know that, that would explain why sometimes it starts OK but gets really hard to get good flow towards the end. thanks this is really helpful!

 

[Sadu]

One thing I discovered, the hard way, is that those STC-1000 probes don't survive long term if you put them in the mash or immersed in fermenting beer. I have gone through dozens of them. They start off giving you slightly bad readings, couple of degrees out, then crazy readings (like 10c off the actual).

My experience is that even a couple of degrees out is enough to give you a different FG to what you expect. I went through batch after batch of beers overattenuating and wasn't until I got rid of the probes and used a handheld thermometer that things came right. Now I put the probe in a thermowell in my pot for regulating the mash and it works great.

Not saying this is your issue, but it you are just hanging the probe into the mash water I'd be surprised if you don't get dodgy readings after a few batches.

 

[Nokie]

If you're having a hard time getting parts you could use a mesh strainer onto of the pot that you're using for a mash tun. That way when your sparge/ return water hits it it'll break up that steady stream am done slowly trickle down onto your grain bed. That would help steady your temps in the grain bed because you're heated water would be spread out through the grains.
Now it looks like it's Making a straight shot to the bottom.
Other than that it's a pretty sweet setup

 

[pyrocam]

Not saying this is your issue, but it you are just hanging the probe into the mash water I'd be surprised if you don't get dodgy readings after a few batches.

That is quite interesting! I was wondering if I was seeing the same thing but thought it was only a couple degree's out, I have been using a multimeter probe and an analogue probe as well to try get a bigger picture. I bought some new probes from DigiKey, they are much smaller than I was expecting I doubt they will last long. I wonder if there are some more reliable probes out, I think I could build a thermowell into the big pot. Ah yeah, this looks awesome , great idea ! thanks !
http://www.ebay.com.au/itm/6-Length...852752?hash=item1eb6709e50:g:NP4AAOSw6n5XsvYC

If you're having a hard time getting parts you could use a mesh strainer onto of the pot that you're using for a mash tun. That way when your sparge/ return water hits it it'll break up that steady stream am done slowly trickle down onto your grain bed. That would help steady your temps in the grain bed because you're heated water would be spread out through the grains.
Now it looks like it's Making a straight shot to the bottom.
Other than that it's a pretty sweet setup

Cool, I will build that out of the perforated stainless I have, should work great.

 

[pyrocam]

Thanks for all the ideas!
I have made a couple pages on my website with some better pictures of the machine now. feel free to let me know if you guys have any other improvements

http://pyrocam.com/beer-brewing-machine-build/

http://pyrocam.com/beer-machine-brew-day/