Tag Archives: featured

Mash Tun Insulation Comparisons – Complete

It is a hard truth that you will lose some temperature during your mash.  In my desire to go electric, I recently purchased the BREWER’S EDGE® MASH & BOIL from William’s Brewing.  Without actually even having brewed a batch of beer on it yet, I already got to work figuring out how to insulate it.  I tested various insulation methods on the Mash & Boil, but the relative comparisons should be valid on any mash tun.  A post with a better review of the Mash & Boil and my reasoning for wanting to go electric will come at a later date.

Nerd Alert!

Warning, the material in this post could get a bit nerdy.


Difficulty: level_5

Easy for you

Time Required:

Just a read for you fortunately.  It took me about a week to perform the experiments.


One of the advantages of an electric brewing system should be accurate temperature control.  With such a new system as the BREWER’S EDGE® MASH & BOIL, there is a lot of discussion about the 6 degree swing in temperature control.  This is pretty well contrasted with much more expensive systems as the Grainfather or PicoBrew Zymatic that may hold temperature within a degree or two.
While I do agree this could and should be safely regulated to a tighter temperature band on the Mash & Boil, I would at least propose that the first line of defense is just to insulate your mash tun so that accurate temperature control is not as critical.  In all reality, this is a turn-key electric brewing system for less than 1/3 the cost of the other systems on the market.


I initially started brewing with a 44 Qt kettle doing 5 gallon batches with a propane burner.  I did notice a decent amount of temperature loss, so I created a thermal wrap to use during the mash.  This was made using some cotton based insulation meant for water heaters.  I did not want to mess with fiberglass based insulation.  When I moved to a 62 Qt kettle and larger batches, I think the larger thermal mass helped maintain temperatures better, but I went ahead and used the same wrap anyway.


With the new system, it had such a different diameter to height ratio, I decided to start from new again.  Since we homebrewers are a thrifty bunch, it usually comes down to whatever we had on hand at the time we needed to create it.  This time for me, however, I had enough time to plan it out and (gasp) actually test it before using it.  As stated before, these results should be applicable to any mash tun that adheres to the laws of thermodynamics.
These results are relevant to a mash because the only thing that will change will be the specific heat of the mixture.  So the best insulation with water will still be the best with grain in the mash.

After my first post (part I) there was some discussion online and in forums surrounding the lack of air gap between the outer layer of Reflectix and the kettle in my testing.  As an engineer, I’d like to think that my test methodology is 100% comprehensive.  Also as an engineer, I’m always willing to accept that I might be wrong and the best way to do that is to attempt to prove that I am wrong.  I then ran variations of the Reflectix configuration only and posted them in (part II).

This post is a combination of (part I) and (part II) so that one can get all the information at once.  If you wish to read them as well, go ahead, but ALL the information from both posts has been combined here.  If future testing is taken on, this post will be updated and serve as the master record.

Insulation methods to test:

Baseline – Stock BREWER’S EDGE® MASH & BOIL kettle

  1. Described as double wall stainless construction
  2. Pros: you don’t have do do anything
  3. Cons: Hypothesis is that this will be the worst performer

Duck brand, cotton enhanced (Non-fiberglass)


  1. Was about $20 when I originally bought it and that is about the going rate at your local hardware store
  2. This was the insulation wrap from my 62Q Bayou Classic kettle
  3. Pros: Fairly inexpensive, relatively easy to find and no special handing required
  4. Cons: A bit dusty when cutting and not as tidy as the Reflectix

Sleeping Bag:

I wrapped the sleeping bag all the way around the kettle once and then had enough length left over to do a sort of “comb over” on the top of it.  I finished it off by holding it on with the bungee cord.
  1. No link, as these have been in my family for a LONG time
  2. Pros: super quick and most people have them on hand
  3. Cons: If you somehow damage it for brewing, you’ll probably get in trouble with your family

3 Layers of Reflectix


  1. It cost me $27 for a 25 foot roll at my local hardware store and is enough for 2 kettles worth
  2. 3 layers from the lip of the kettle to the top of the control box
  3. 3 layers loosely fit on the lid
  4. Pros: Easy to work with, clean look
  5. Cons: Really requires a semi-custom fit for it to perform well
  6. I’ll have a future post with cut dimensions so you can make your own

Reflectix with 2 cm gap

  1. The Reflectix website recommends the gap to consist of 3 layers of the bubble insulation
  2. https://www.reflectixinc.com/applications/diy/water-heater/
  3. I actually created 2 rings (top and bottom) composed of 3 layers of Reflectix that were 2 cm wide
  4. Then I used the 3 layer baseline Reflectix jacket wrapped around it.

026-gap rings026-gap distance026-gap as tested

Reflectix  “Dome”

  1. Having thought of the sleeping bag winning out big time, I wondered if it was due to the superiority of the sleeping back insulation properties or the fact that with that test, the entire kettle was surrounded (top and sides) with the sleeping bag.  Whereas, with the other insulation methods, there was a gap for practicality purposes between the lid insulation and the wall insulation.  I questioned whether this open gap was allowing more heat to escape.
  2. I constructed a dome that encapsulated the entire kettle.  The diameter was about 18″ (about 2.5″ air gap to the kettle surface) and the height was 28″.

026-dome as tested

Other methods considered (since I have seen them used), but not tested

  1. Fiberglass water heater insulation (I don’t want fiberglass anywhere near my beer)
  2. Single and double layers of Reflectix to understand the impact
  3. Custom molded expanding foam mold
  4. Red-Hooded sweatshirt

Setup and Test Methodology (Identical to the last time) :

I have not modified the Mash & Boil in any way.  I just used the unit in stock condition and let the temperature controller do it’s thing to get the water up to temperature.  I used exactly 6 gallons of RO water for the experiment.
The kettle was placed in my basement storage room, which maintained a consistent 65 degF throughout the testing.
I had 3 temperature probes in the kettle.  One at 1″ from the bottom, then another 6″ up and another 12″ up.  This was a nice spread for 6 gallons of water.  In reporting temperatures in this experiment  I am only using the temperature sensor at the 6″ height.  The other sensors were a proof of concept for some future testing I plan to carry out.  I did see some stratification in the temperatures over time as the water cooled, but for consistency, I chose the 6″ probe.
To start the each test, I topped off to 6 gallons and set the Mash & Boil to 215 degF and let it ramp up.  As soon as the system was boiling, I turned it off and unplugged it from the wall.  Temperature measurements were taken approximately every minute.  I allowed the temperatures to cool to somewhere around 100 degF or as long as I could stand it.  Absolutely no stirring or opening of the lid occurred during the cool down.
The critical stage in the test was when the water cooled to 155 degF.  At that point, marker would be taken and then compared to the temperature exactly 60 minutes later.  This would be indicative of a typical mash temperature and the relative temperature loss during the mash.  Yes there will be different thermal capacities of a water/grist mix, so to reduce the experiment to just the insulation, straight RO water was used.


I normalized the cool down datasets so that the start time (t=0) was the same for each configuration at 200 degF.  As a visual reference aid, I placed a line at 155 degF to see what the curves look like near mash temperatures.


One can clearly see here that the baseline configuration with no additional insulation decreases in temperature the most rapidly.  The cotton based insulation is a bit better, then beat by the Reflectix configurations and then the sleeping bag.  You can see that the 3 Reflectix configurations are quite close to each other when compared to the rest.

027-Overall Cooling Summary

Reflectix only shown below
026-Reflectix Cooling Summary


This small table places numerical values on the temperature drops through a simulated mash temperature window.  I calculated these temperature drops by taking the very last data point that was greater than 155 degF.  Then I grabbed the next data point that was +60 minutes from that initial point.  The values shown are then the differences between those two temperatures.


027-Full Summary


To glean even more from the data, I plotted the 3 different configurations only through the mash temperature window.  I normalized these curves so that the start time (t=0) was the same for each configuration at 155 degF The left axis shows the actual temperature reading, while the right axis shows the temperature drop, relative to the 155 degF starting reference temperature.  I also placed a helper line at 155 degF.


If you are to accept the belief that most of the conversion is done within the first 15 minutes of the mash, all of the Reflectix and Sleeping Bag insulation methods show a drop of less than 1 degF within the first 15 minutes.

027-Overall Mash Summary

Reflectix only shown below

026-Reflectix Mash Summary


The extended time plots do show the dome to be the best, followed by the 3 full layers and lastly the 2 cm gap.
I am surprised that the recommended method from Reflectix was slightly worse than the full 3 layers.  I’ve struggled to come up with a reason, but I think it would require more thought and analysis than I feel like spending on it.


It appears that when choosing Reflectix, that you almost can’t go wrong with any of the 3 methods as far as mashing goes.  Due to the 0.2 degF difference in temperature drop between the 3 different methods during the simulated mash time, I’d almost call it a tie.  However if you want to pull other factors in, depending on your preference, I can add some additional points.

Differences in Reflectix configurations

026-Reflectix Cooling Summary
The extended time plots do show the dome to be the best, followed by the 3 full layers and lastly the 2 cm gap.
I am surprised that the recommended method from Reflectix was slightly worse than the full 3 layers. I’ve struggled to come up with a reason, but I think it would require more thought and analysis than I feel like spending on it. Precisely why I just tested and reported the results.


Everyone has their own selection criteria when choosing the best equipment for their needs, so I hope you’ll find the information reported in this post useful.


It appears that when choosing Reflectix, that you almost can’t go wrong with any of the 3 methods as far as mashing goes. Due to the 0.2 degF difference in temperature drop between the 3 different methods during the simulated mash time, I’d almost call it a tie. However if you want to pull other factors in, depending on your preference, I can add some additional points.


There is something to the gap and whether it is just plain air or air encapsulated in bubble wrap, it is as effective as air naturally is.

I’m not suggesting that I do the testing, but I’d be willing to be that if you simply took a bunch of mylar balloons and created a dome as I did (or re-created the other methods), you’d get a similar result. Nothing particularly special about the materials involved, just the application.


3 Layer Reflectix:

Definitely adds the most material, but is what I had already made, so for me, that’s what I’m sticking with.  Plus I just felt that without the spacer rings, there would be less material to snag on something else.

Reflectix with 3 layer gap:

Probably the least amount of material needed and arguably the same performance as the other 2 options.

Reflectix Dome:

Also a lower amount of material, but for storage, if you want to maintain the shape, it is quite bulky.  I would caution against this method if you have electronics or moisture sensitive gauges integrated with your kettle.  When using this dome, it gets quite steamy in there and moisture could find a way into the electronics enclosure or gauge.

Reflectix Insulation Jacket for your Mash Tun

Do you want to make your mash tun or electric kettle look like it’s been prepped by SpaceX and give it some good thermal characteristics?  Read on…
Sorry if I offended both SpaceX or NASA employees in one statement.

Difficulty: level_5

This is pretty easy.  It just requires some simple measuring, cutting and taping.  The patience portion of this may not be so easy depending on how good you are at measuring, measuring, calculating, measuring, measuring, marking, checking, measuring and cutting.

Time Required:

maybe an hour at the most.  Depending on how meticulous you are and how many do-dads are sticking out of your mash tun.


In my last post, Mash Tun Insulation Comparisons I ran an experiment on various forms of insulation for your mash tun.  My platform was the new Brewer’s Edge Mash & Boil.  Even though the jacket was made specifically for the Mash & Boil, I’m also going to lay out how to measure out your Reflectix insulation jacket.



Tools/Materials Required:

  • Reflectix
    • I purchased a 24 inch wide x 25 foot long roll for mine.  It is about enough for 6 layers , plus lids on a 12 inch diameter mash tun.  I’m only making 3 layers here.

  • Reflectix tape
    • Any other HVAC metallic tape will serve the same purpose
    • I just chose the Reflectix brand, because it didn’t have any writing on it.

  • High temp hook and loop
    • The normal Velcro brand adhesive only listed something up to 140 degF.  Since I was going to possibly be boiling with mine on, I wanted to find something rated higher.  This brand (although pricey for what you get) is rated up to 212 degF (100 degC)
  • Utility knife, get a fresh blade.
    • Believe it or not, the Reflectix dulled a blade from cutting 2 jacket’s worth
  • Long straight edge (great cutting guide) or tape measure

Method /How it’s made:

Here are the basic principles of measuring out a jacket for your mash tun.
  1. Choose a reference start location for your measurements, both in height and distance around the kettle
    1. You’ll want to choose something that you will want to stop and start at (spigot, sight glass, etc)
    2. I chose the spigot for the perimeter and the top lip for the height
  2. Try to sketch out what the jacket will look like rolled out with windows for all of the obstacles (look at my provided template)
  3. Remember, it’s easier to remove material than add, so as they alway say, “Measure twice, cut once!”
  4. When adding an additional layer, remember that the cutout locations will move further from your reference at each layer, due to the additional diameter added with each layer.
    1. For the Reflectix, it averages out at about 0.225 inches thick, so here is quick table that shows the amount of additional length to add for each layer length to just make it around.  If you want to add a tab for velcro, I’d use about 2 additional inches as I did.
    2. The formula for this addition is: 2*Pi*0.225*(layer number)
  5. 025-Layer Offset Chart
  6. Then for each cutout, it will be a ratio of the table above, depending on how far around the circumference it it.
  7. In all reality, you might outsmart yourself with the math, so there is no shame in just doing it all by hand.  Just go one layer at a time, then tape it all together when you are done.
  8. For the lids, I just set the lid on top of the Reflectix and traced around it with the utility knife.  Then I just cut a little tab to go through the handle on the top.
  9. When you are done,  you can simply tape all of the ends together to make it nice and neat.  I chose to just tape the very ends, since on the curve the stiff aluminum tape was going to look pretty wrinkly

Completed Jacket:

Here is the dimension scheme for a 3 layer Reflectix jacket for the Brewer’s Edge Mash & Boil.  Mine sits just on top of the display panel and just under the top lip.  I also rounded dimensions to the nearest 1/4 inch to make measuring and cutting easy.
025-Reflectix Insulation Jacket
The hook and loop was pretty straightforward
I didn’t want to mess with finishing all of the edges, so I just picked key areas.  I can always go back and add it if necessary.
025-Finished Edge
And here is the completed Reflectix jacket
025-Completed Jacket
If  you enjoyed this post, check out other posts on the site and be sure to shop through some of the affiliates on this site.

Darth Vader Tap Handle


In honor of the long awaited release of Star Wars: Episode VII The Force Awakens I’m showcasing my Darth Vader Tap Handle.

 Difficulty: level_5

Due to the investment in a 3D printer and the amount of time it takes to get one dialed in and making parts, this one gets a high difficulty rating.

You also must posses some CAD design skills to generate the required files to send to the 3D printer.

Time Required:

This one was fairly easy, but printing time was about 6 hours total.


  • Existing tap handle
  • Tap handle topper (In my case the Darth Vader bust)
  • 1/4″ wooden dowel rod
    • About a 1 to 1.5″ length
  • Glue
    • Super glue is best
    • It works well with the ABS plastic and the wood
  • 3D printer

3D Printer

Ever since I first saw my first rapid prototyping machine in college and then to a greater extent, seeing that this technology was nearly affordable for a DIY person like me, I’ve had a child-like fascination with these awesome machines.  It may sound goofy, but I’ve got the same level of amazement that I did when my Dad bought our first computer in the early ’80s and I was able to type my name and have it appear on our television.

I got the Flashforge Creator and I am very happy with it.  It had the right balance of cost, dual-extruders, reliability, non-proprietary filament and has required me to do a little bit of tinkering that has allowed me to better understand the capabilities 3D printers.

Great Fermentations

Celebrate by brewing the Milleniale Falcon beer kit from Great Fermentations.  Today only (December 18th, 2015) is a special 38% off deal. No promo code needed for the deal; just add the kits to your cart and go! Click the link below to see the list of eligible light and dark side beer kits!



It is really simple, once you have your handle and the topper printed.  I just used a 1/4″ dowel rod to attach the topper to the tap handle.  Drill a 1/4″ pilot hole in the top of the tap handle.

023-Vader Dunkel Side 3DP Front

Text creation for tap handle

At the time, I couldn’t find a font that looked similar to the Star Wars font, nor could I find a font generator, but now there are a few out there.  Here is one for example:

Font Meme

Tap Handle Creation

Just follow my guide for Super Easy Tap Handles

Darth Vader Bust

If you have a 3D printer and want to print one yourself, go to Thingiverse to download the STL files and build your own.

Darth Vader Tap Handle Topper on Thingiverse

Don’t have a Thingiverse account?

If you don’t have a Thingiverse account or have no interest in creating one, you can download the CAD files by subscribing using the form below:
Creative Commons License
This work is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 Unported License.

By clicking on the download, you agree to the terms of this license and to be added to the awesome fermware.com subscriber list. Don’t worry, you won’t receive a bunch of trub in your inbox.

Please provide your name and email address for your free download.

Please wait...


023-Vader Dunkel Side 3DP Side