I put together a mash tun tonight... I have questions....

[tamoore]

Firstly, this site has been most helpful over the past few weeks as I've learned my way around brewing. Thanks for all the help you've given.

Now, on to my questions.

I used a Coleman 48 quart cooler, and a stainless steel braid......

When I look at this thing, I think - the wort is going to come out only to the lowest point of bulkhead fitting, regardless of how low the braided hose is sitting. How does this hose, which is full of 'holes', actually transfer liquid to the output fitting? Does it? It doesn't seem like it could.

Should I just scrap this and throw together a manifold? And if I do, how do these tubes - with the slices all over them - transfer wort to the output fitting? I can almost see an improvement in a manifold, just due to the fact that you get some siphoning action until the point at which the liquid level falls below the deepest 'slice' in the manifold tube.

Lastly, I've run an experiment with hot water in my new mash tun over the past hour, and the results have been disappointing...

I put 156 degree water in the tun, and closed it up with a thermometer probe it in. Just heating up the tun took the temp quickly down to about 152.0. I started a timer at 60 minutes, and the temp continued to steadily drop. I put a sleeping bag over the cooler at about 15 minutes in, and it slowed the loss a bit, but at the end of an hour, It was down to 143.0. I've heard that some people lose only 1 degree over an hour of mashing, so I was kind of upset at the loss.

So, my question here is; Does the presence of grain in the tun help retain the heat any better, or can I expect this kind of loss in my equipment? If so, what would I do to negate this 10 degree loss?

Thanks in advance.

 

[Wellshooter]

So, my question here is; Does the presence of grain in the tun help retain the heat any better, or can I expect this kind of loss in my equipment? If so, what would I do to negate this 10 degree loss?

Yes the grain will help hold more heat in, how much is a good question. But coolers are designed to keep heat out and thus have zero insulation in the lid. Have you drilled and filled the lid with insulating foam? That will help a lot. As for draining the cooler properly see the thread on 'tipping' https://www.homebrewtalk.com/f36/why-cant-you-just-tip-cooler-bit-drain-all-out-163920/

Another consideration is the dead space in the tun. I use a 40 qt and do 10 gallon batches of <1.050 OG beer. If I wanted 'Big' beers above 1.050 I would probably run out of dead space. I haven't calculated for your cooler and 5 gallon batches but you may be a little large for that.

 

[Zen_Brew]

You are correct that the liquid will only drain to the lowest point at whcih the opening in your braid/manifold sits. A manifold will drain to a lower level as long as you only put slits on the portion of the manifod that lays on the bottom of the cooler. Putting them on the bottom of the manifold only will get you the lowest drain level. What is left in the dead space is not generally recoverred and is compensated for by a slight increase in your water volume and grain bill.

There will always be heat loss to heating up the tun, and heating up the grain. This has to be compensated for with the temperature of the strike water. Software such as Beer Smith will figure this out for you. Generally you add water somewhere in the 165-175 degree range to compensate for losses to the grain and the ton heating up. Some people pre-heat the tun as well. 6 of one 1/2 dozen of the other.

The presence of grain will slow heat loss some as it is a thicker medium, but not entirely. Is the lid insulated. Some coolers do not insulate the lid. Other than the lid, putting a blanket over it (as you did) and wrapping the drain vavle with a towel as well (the metal acts as a heat sink drawing temperature out of the mash) are the best defenses.

Temp should stabilize ofter a couple minutes of stirring it all up and letting the tun heat up. After the first few minutes, You should be able to maintain temp loss to 2 degrees or better over an hour if the lid is insulated. Once you are familiar with your tun, you will know where to set your strike temps. I usually start out a couple degrees higher than my software tells me because it is much easier to add room temp water to drop my temp a degree or two than it is to raise it a degree or two if I end up low going in.

 

[tamoore]

Thanks for the replies. I'm going to the hardware store this morning to buy the parts to build a manifold, along with a can of 'Great Stuff' to insulate my cooler top.

Now, another question: Do I have to worry about the expanding foam ballooning my cooler top? I'm not sure how much this stuff expands, but the lid seems to be just a hollow blow molded shell which could be susceptible to such a thing farther away from the stronger edges. Is there a method to protect against that, or is it not an issue?

 

[brewagentjay]

I did an SS braid mash tun on Wednesday and used it same day....It worked well. SS braid got a little caught up in stirring but I did have a 30" SS braid.

I used 10G cyclinder cooler, but it held temp with in a degree for 60 minutes I'd say. I drained way more than I needed for the batch so you should be okay I's day insulating the top of cooler biggest thing you need to accomplish.

 

[Wellshooter]

Now, another question: Do I have to worry about the expanding foam ballooning my cooler top? I'm not sure how much this stuff expands, but the lid seems to be just a hollow blow molded shell which could be susceptible to such a thing farther away from the stronger edges. Is there a method to protect against that, or is it not an issue?

I drilled six holes just big enough for the 'straw'. When the foam expanded it oozed out the holes and hardened. It didn't seem to expand the top any.

 

[PT Ray]

When I look at this thing, I think - the wort is going to come out only to the lowest point of bulkhead fitting, regardless of how low the braided hose is sitting. How does this hose, which is full of 'holes', actually transfer liquid to the output fitting? Does it? It doesn't seem like it could.

This exact thing is covered in a "Brew Strong" session. The braided hose is really better suited for batch sparging. Here you can get away with the flow being pulled directly by the fitting. For fly sparging this is a concern and a properly designed manifold is important. You want as much of an even pull across the bottom as possible. If the flow is too strong by the valve the grains won't evenly sparged. The majority of the flow will just be the area above the valve.

 

[tamoore]

Thanks again for the input, everyone. Here's what I did today:

Replaced that braided hose with a manifold. It was cheap and easy, and I think I'll be happier with it. Still need to cut the slots, but I'll probably do that on a mill.

Insulated the cooler top. I sprayed about a bottle of that 'good stuff' in there. As a bonus, it was on sale. I hope it got filled OK....

Next Saturday is AG brew day #1....

 

[bootney]

I plan to do my first AG next weekend and have a similar set up with the exception that I used larger ID CPVC pipe, and drilled holes rather than slits.

I'm glad I came across this as I had my manifold openings facing up instead of down. Just curious to see what your efficiency was like.

 

[strat_thru_marshall]

The manifold and insulation design looks much better. I consistently get 78-80% efficiency with my copper manifold/10 gallon cylindrical cooler setup...I'd think you could do the same with this setup.

 

[ibbones]

I like your manifold a lot better than my SS braid. What size CPVC did you use? How did you attach the tube to the spigot?