Mash temp measurment

[TipsySaint]

I have an igloo cube cooler and I'm wondering what the best location to measure the mash temp is?

I have a long wire probe that I'm thinking of affixing to my mash tun somehow....and somewhere....so I can have a consistent measurement point....

Opinions are appreciated and opinions with facts and citations are worshiped....:rockin:

 

[Cyclman]

I like to measure my mash at different locations, depths, etc. It can vary a few degrees.

 

[TipsySaint]

I'm more looking to monitor. i'll spot check at dough in and during and hot water additions but simply for monitoring in a single continuous location...It makes for a knowledge base much simpler....

 

[william_shakes_beer]

If I had an igloo cooler and wanted a monitor point I'd install it in the lid with the probe extended to the 3d center of the mash. Open the lid and the probe swings up out of the way for stirring.

 

[blizz81]

I'm more looking to monitor. i'll spot check at dough in and during and hot water additions but simply for monitoring in a single continuous location...It makes for a knowledge base much simpler....

I kind of went away from a static monitor when I used a cooler-style tun, really because 1) it doesn't tell the whole story (as mentioned, you want to know from various points - edges vs. center, top vs. bottom, etc) and 2) once you do a couple spot checks during a couple brews, you get to understand how your equipment behaves and that will pretty much be a constant going forward with that equipment.


If you still want a static read with those things in mind, I'd plop it somewhere in the middle of the mash.

 

[TipsySaint]

I'm having issues getting good conversion and I'm down to temp and grain crush....I figured temp is simpler to rule out than grain crush as I don't have my own mill....

 

[blizz81]

Temp won't really hurt your conversion unless you happen to be quite a bit over your target mash temp, I'd think. That said, it's nice to know how your equipment is performing re: holding temp. A penetrating probe of some sort (longer if you're a vertical cooler) would be optimal to poke around at various points in the mash - a wire probe like yours might be enough to make sure you're not too high / in the 160s or something.


If you look around, I'd say something like 80% of the "efficiency" threads here are related to crush. If you're getting your grain crushed at your LHBS, you can ask if they can adjust their mill tighter for you and / or to have them run the grains through twice. Ask Santa for a mill for xmas!

 

[max384]

I'm having issues getting good conversion and I'm down to temp and grain crush....I figured temp is simpler to rule out than grain crush as I don't have my own mill....

Well there's your problem!

When you say you're having conversion problems, do you mean that it's taking a long time for your iodine test to come back as finished converting? Or do you mean that your efficiency is low?



IMO, there is no reason not to own a mill if you're doing AG brewing. You can get an inexpensive hand cranked corona mill for under $30 shipped. Then you can set the crush to however fine you like. Plus, you can buy uncrushed grain in bulk and it will store for quite awhile uncrushed. I had TERRIBLE efficiency numbers (like 40-50%) when I first started doing AG. I went up to about 80% on the first brew that I milled my own grains. Turns out my LHBS didn't have a good grind at all.

If you don't like milling by hand, you can replace the turn handle with a threaded rod or a bolt that you grind the head off of. Then just attach a drill and you've got an insta-powered mill! That's what I did to mine, and it has worked beautifully. I mounted it on a scrap wood frame, attached a tubberware container to the frame, and now I can mill a full grain bill for a five gallon batch in just a couple of minutes. Originally I was just going to do this as a temporary fix until I got a roller mill... But it's worked so good that I don't know if I'll ever switch.

Here's a picture of it. I also used some aluminum sheet metal to create a bigger hopper. It's ugly as sin, but works well with grain bills of up to about 12 pounds, and beats refilling the hopper all the time.

 

[TipsySaint]

I'm pulling like 60% efficiency (i'm nailing my volumes though) and I'm a specific about knowing what is happening. I will likely end up doing both a fixed probe on the cover and my own mill. I'm thinking I will start asking my LBHS to double mill....doubt they'll adjust the mill. My manifold is a copper baffel with slits cut in it, so I can't get to fine or it will suck through.

 

[max384]

I'm pulling like 60% efficiency (i'm nailing my volumes though) and I'm a specific about knowing what is happening. I will likely end up doing both a fixed probe on the cover and my own mill. I'm thinking I will start asking my LBHS to double mill....doubt they'll adjust the mill. My manifold is a copper baffel with slits cut in it, so I can't get to fine or it will suck through.

I think you're wasting your time with a fixed probe. As has been said, you really need measurements at different spots and/or stir quite a bit to get the temperature fairly even throughout for the temperature reading to mean anything.

Even if your temperatures are spot on, or vary wildly, what will that tell you with a fixed probe? You're still going to need to see what the temp is in a few places. If you want a good picture of what is going on, stir it well at say 15 minute intervals and measure the temperature in a few places and then see where you end up at the end of your mash. You'll then see how the temperature drops over the course of your mash.

Frankly though, I think you're barking up the wrong tree. Nearly everyone with an efficiency problem actually has a crush problem. After reading thread after thread about guys who had their grain double milled with little to no improvement, and wasted time troubleshooting other less likely problems, before finding out it was a crush problem, my first troubleshooting step was the crush. I'm glad I went that route. Common things are common.

When you have an efficiency problem and you're buying pre-crushed grain and trying to rule out everything but the crush, it's like trying to figure out why your chest hurts when a knife is stabbed into your chest. Sure, you could be having a heart attack... But most likely it's the knife in your chest. I'd probably start treating the knife wound before I ruled out a heart attack.

 

[TipsySaint]

I know but I don't want it to be the knife because then well it just leads to spending more $$$ on a mill and grain storage....dang it! So is double milling worth the time or should I just get a cheap mill and go nuts?

 

[TipsySaint]

So if multiple measurements are best, how do automated systems function?

 

[max384]

I know but I don't want it to be the knife because then well it just leads to spending more $$$ on a mill and grain storage....dang it! So is double milling worth the time or should I just get a cheap mill and go nuts?

I've never double milled before, but I'd imagine it would help the crush some.

In the long run, you'll save money with increased efficiency (and thus less grains for a given brew) if you mill your own grains. If you buy in bulk because of that, you'll save even more money.

So if multiple measurements are best, how do automated systems function?

I don't do any automated brewing, but I believe most of those type systems recirculate mash water and some may also continuously stir the wort.

I'm sure someone else who is more familiar with these systems will provide better detail.

 

[Reisende]

...I believe most of those type systems recirculate mash water and some may also continuously stir the wort.

As max384 said, systems that are automated to some extent, and that measure mash temp at a single fixed point, must either A) stir the mash or B) recirculate the liquid mash and measure that. That's the only way a single point of measurement will work. Big commercial lauter tuns have rakes that slowly turn, lifting the grain bed and increasing extract, and keeping temps even. Most of these even measure temps at multiple points.

That being said, I TOTALLY understand where you are coming from, I am a "control" freak as well (control in the sense of process control/general geekines). I am about to build my AG setup after nearly two years of extract/PM, and I will be including a mash stirrer in addition to a steam injection manifold in the bottom of the tun. Good luck, and check your crush!

 

[blizz81]

So if multiple measurements are best, how do automated systems function?

Walking down the lines of blizz81 brewing history, I did a lot of reading about moving to AG and what people used. We had a horizontal cooler with a spigot already so we started with that. I didn't take as good of notes as I should have back then but measuring with a little $4 harbor freight digital thermometer, I think it kept temp ok. I don't think I was able to check all points in the mash with how long the probe was, though.

We had other issues with the setup and my roommate at the time was getting into the hobby and liked throwing $ around. It seemed almost universal that people only lost 1, maybe 2 degrees in vertical GOTT coolers, and we found a pricey product from the west coast designed after these, but specifically for homebrewers with a false bottom, thermometer included, sight glass, other connections for recirculating, etc. Once we got to using it, we found this lost quite a bit of temp over 60 minutes - up to like 15 degrees around the edges, even with a sleeping bag around it. This was after buying a more expensive Thermoworks long probe as we found the thermometer included would read pretty nutty, could never tell if it was stratification or bad thermometer. It was difficult to brew a beer that wasn't super-fermentable.

Because I wanted control (like you), I got a sanke keg and had intended to do direct fire on it, but I saw Bobby's bottom-drain hookup and thought that was cool (my No Wort Left Behind campaign), so I changed course and went RIMS. The tube is standard - heater element at one end, probe at the other, pump recirculating wort out the mash tun, through the tube, back into the mash tun. Probe measures the temperature of the wort passing through the tube. But you don't just trust the probe - you still want to know how the mash is doing. I've found if flow rate is consistent / moderate, the mash quickly settles to about 0.5-1 degree below what I set on the PID, and the delta at all points in the mash is within 1 degree. I usually end up setting the PID for one degree higher than my target mash temp.


If your mash tun does only lose a degree over the course of a mash and you're confident in the probe you're using (for what it's worth, the Harbor Freight ones I had measured within 0.5 degrees of the pricey Thermoworks probe), and you're measuring all over your mash and the delta is low, then even if you're a control freak you'll be able to RDWHAHB.

But in your case, especially if you're a control freak, get at least a cheap mill to where you can measure and control your crush

 

[Black Island Brewer]

I have an igloo cube cooler and I'm wondering what the best location to measure the mash temp is?

I have a long wire probe that I'm thinking of affixing to my mash tun somehow....and somewhere....so I can have a consistent measurement point....

Opinions are appreciated and opinions with facts and citations are worshiped....:rockin:

I've chewed on the question of temp probe placement on and off over the years, and I finally settled on this: I don't like to have to mess with my mash. I like to dough in, stir thoroughly, seal it up and ignore it. Logically I know that there can be hot and cold spots, and that the longer my mash sits, the cooler it becomes, from the outside of the tun into the middle. And since I don't have a stirring device, and don't want to make one, and since opening the mash tun to stir not only lets out heat, but is just one more variable to contend with, I have fixed my probes (plural because I have a traditional 3-vessle tun, and a BIAB kettle) and I just let it ride. Thanks to good software and lots of stirring, I usually hit my initial mash temps within a degree. It helps that on both systems I heat my strike water in the mash tun, so no thermal loss from the mash tun temperature, and it helps that my probes measure mostly in the center of the mash. I think it also helps that I do a mash-out, so if there were areas that were slower to convert, the mash may spend a little time as it ramps up to get a little more conversion.

What I like about my method is that it is easy and it is repeatable. I can easily do the same thing over and over and expect similar results. The biggest variable ends up being the ambient temperature of my garage, which can be 90F in the summer and 30F in the winter. Fortunately, living in the wet half of Washington State, the temperatures are usually more temperate, and when they're not, and it gets too cold, the heat from my burners help some with the ambient temp (I can close my garage door once I kill the flame).

Just my thoughts, hope it helps.

 

[johngaltsmotor]

I just tied a piece of string to the end of the 16" glass lab thermometer and tied a carabiner on the other end. I drop it in the center of the MLT, then pull it out to measure. Flop the string over one of the handles. Toss the themometer out to stir, then plunge it back in. After the first 4 or 5 batches it's now just done out of habit, things are repeatable so I don't really use it except to double check. I did a batch where I alternated and put the probe in the center for 15min, then near the outside for 15min and only had about 1-2deg deviation so I quit spot checking and just put it in the center now.

 

[TipsySaint]

So I'm getting that i should:

1: fix the dang crush issue by buying a corona mill and fabing up a hopper
2: mount something that can get to about the center, both left right and top bottom.

I feed my water into mash via a pump in the bottom with the grain in place and once I get my volume transferred I stir like hell...wondering if that method might be contributing to the issue as well.....

 

[BrewWho]

I am one who likes to be able see what is going on. I know that a fixed temp. reading location is not the most accurate but it gives you an idea of how close you got and what kind of temperature change you are getting.

I ended up getting Auberins to build one of their weldless probes for me but in an 8in version. Drilled a hole about 1/3 the way up in my cooler and stuck her in. So far it has worked well, iv even smacked it pretty good with my paddle but it held in place with no leaks.
Im not saying its going to rule out the efficiency problem but its nice to have

http://www.auberins.com/index.php?main_page=product_info&cPath=20_15&products_id=454