Improved boiling on the stovetop!

[FlyGuy]

After getting used to my keggle and propane burner this summer, it has been hard to go back to stovetop brewing this winter. Last week it almost hit -40, and brewing outdoors just isn’t very attractive right now. So I have been back to the stovetop, mostly only 3 gal batches because I haven’t worked up the energy to do my old split-pot boil routine (i.e., half the wort in each of two 5 gallon pots on the stove).

The problem with my stove, which is a problem shared by many, is that a single burner doesn’t throw enough heat to boil all my wort from a 5 gal batch in one pot. Previously, the best I could do was about 3.5 – 4 gallons in my flat-bottomed stainless pot (uncovered). However, I think I have this problem licked. Tonight I easily got 6.5 gals to a rolling boil in one pot on my stove.

First, I used my cheap 30 qt aluminum pot that came with my propane burner in a cheap turkey fryer kit. I am a big fan of aluminum because it transfers heat better than stainless (see here), and in a water trial, I was able to get 5 gals to a rolling boil in it (significantly better than the SS pot).

Second, I added a reflective foil blanket to the pot (similar to what many guys drape over their keggle MLTs to keep the heat in). The idea is the same here – the reflective insulation helps prevent heat from escaping out the sides of the pot. It was enough to get 6.5 gals to boil instead of only 5 when I used the same pot on the same burner but without the foil blanket.

Here are my old and new pots respectively:

​

I made the reflective foil blanket out of reflective insulation found at Home Depot. I used two wraps around the pot, and secured everything with foil tape. I cut notches for the pot handles, and then tucked the top and bottom ends under and taped them in place, leaving a good inch gap at the bottom (I was worried that plastic part of the insulation would melt if too close to the burner). I also did a couple of wraps of foil tape around the bottom of the blanket to reflect away heat from the burner. The nice thing about the blanket is that I can easily slip it on or off, e.g. if I want to use this pot outside on the propane burner again. The materials for the blanket cost about $14.

 

[conpewter]

Think this would work for a gas stove or would I be setting my pot on fire? (I already keep a fire extinguisher in the kitchen just in case...)

 

[david_42]

Most of those reflective materials are aluminized plastics. You'd probably be better off with the foil-backed engine compartment insulation sold at auto stores.

 

[FlyGuy]

Yes, I agree with David -- I wouldn't use this method on a gas range. A flame retardant material will be necessary for your case.

 

[malkore]

FlyGuy and I have the same issue: our ceramic range tops have these little heat sensors built in that prevent the element from getting so hot it damages the cooktop surface.

Nice call on a fix for our problem!

 

[sirsloop]

I just position the pot in between two gas burners and set them both to high. Fire it up!!

 

[FlyGuy]

After a successful trial run with the insulated pot on the stove last night, I tried my first single-pot, 6.5 gallon boil on my stove. The recipe was an inky black robust porter, and to my delight the stovetop had no problem whatsoever getting the full volume to a rolling boil. In fact, I had to turn down the heat from MAX to 7 after adding the leaf hops because the boil was getting too vigorous. I am SO happy to not have to do the split-pot two-step shuffle anymore!

Foam Control: I gotta put another plug in for this stuff. Magic. I had that turkey fryer pot within an inch and a half of the rim, and there was no danger of boiling over at ANY point in the process. Highly recommended stuff! Turns your 30 qt pot into a 40!!!

 

[bigjohnmilford]

Thanks for the info. Great post. I didn't think we could do a full boil on an electric range. That's awesome. We still have a few bucks left on a Home Depot card.

 

[nealmc]

Does anyone use insulation on their kettles on a gas range or propane burner? I'd love to try this on my gas range, but not sure of what material to use. I am not familiar with the engine compartment insulation. Is it fiberglass or mineral wool based? I saw some fiberglass and mineral wool based material on McMaster that will go to like 1000 degrees F, but I worry about getting fiberglass dust anywhere near my beer. Any product that I would use to seal it up would also have to be fireproof, so there goes duct tape or the aluminum foil tape. Just wondering if anyone has had any experience with this. Thanks.

 

[Kai]

Hm. My solution has been like this, but less effective, more dangerous, and higher maintenance. I just wrap a towel around my aluminium pot (I believe it's identical to FlyGuy's - we probably both got them from Canadian Tire.) And hold it in place with duct tape. I've only lit one on fire so far, and it was my least favourite, so that's okay. It also helps if I accidentally boil it over--nothing reaches my cooktop.

I guess what I'm saying is, I'll probably be making one of those. Here's hoping CanTire (the only hardware-ish store within walking distance) carries this stuff.

 

[njnear76]

This is an awesome idea. Do you think I could boil 6.5 gallons on my ceramic top stovetop using a SS pot with a foil blanket?

 

[FlyGuy]

This is an awesome idea. Do you think I could boil 6.5 gallons on my ceramic top stovetop using a SS pot with a foil blanket?

Possibly. It will all depend on the output of your stove and the bottom of that SS pot. If the pot has a flat bottom (especially if it is a copper or aluminum sandwich to help conduct the heat), then that will help tremendously. But those flat-top burners are notoriously inefficient. The insulation will help some, but the pot bottom and burner are the critical elements.

 

[njnear76]

Possibly. It will all depend on the output of your stove and the bottom of that SS pot. If the pot has a flat bottom (especially if it is a copper or aluminum sandwich to help conduct the heat), then that will help tremendously. But those flat-top burners are notoriously inefficient. The insulation will help some, but the pot bottom and burner are the critical elements.

Quite true. I like my stove because it's easy to clean, but it takes forever to warm up.

I guess my other alternative if I wanted to brew inside would be to use a 1500 Watt heat stick with the stove. That might be enough power.

 

[tentacles]

I found that on an ordinary electric stove, if you line the bowl shaped piece underneath with aluminum foil, my pot heats up quite a bit faster (5 gals to boil in 20 mins instead of 30). Plus, there's the huge cleanup benefit (wad it up, toss it out). If I ever get my hands on a bigger pot, I will probably wrap in the foil bubble wrap and do my boils on the stove still, at least the indoor ones.

 

[vthokie98]

Flyguy...you are the bomb. I made this reflective blanket for my 30 qt SS turkey fryer pot and worked like a charm...I was doing 5 gal boils and it would boil but wouldn't get to a good roiling boil...with the blanket i'm now boiling close to 6 gal and getting a nice good roiling boil. Thanks for the great idea.

Mike

 

[Sheaffdogg]

So I'm trying this out with my new 36 qt SS pot on my gas range. I brought a full 5.5 gal to a boil in about 15-20 mins, which rocks, but i hit a bit of a snag. The inner plastic bubbles of the foil blanket melted in the lower half of the pot. I need to look for something that is flame retardant as mentioned in previous posts.

I should have just read the specs on the damn package, where it lists the max operating temp of 180 degrees F... There's a heads up for those of you shopping for the stuff. I didn't see any other kind when I was at Lowe's yesterday.

I still give props to FlyGuy for the original idea. It definitely works and I am enjoying a nice rolling boil right this minute!

 

[Sheaffdogg]

So I was searching around online and found the stuff that I should have used on my pot for the stovetop. If anyone's interested, here's a link to a site to buy online:

http://www.jcwhitney.com/HEAT-SOUND-INSULATION/GP_2010475_N_111+10201+600014099_10101.jcw

They say its the stuff that NASA uses to protect the shuttles!

I guess I'll use the other stuff to wrap my pipes...

 

[sirsloop]

Nice! I think I'll try that!

 

[sirsloop]

http://cgi.ebay.com/ebaymotors/ford...016QQitemZ260223072567QQrdZ1QQsspagenameZWD1V

FIRE RATING: Class A/Class 1
MOTOR VEHICLE SAFETY
STANDARD 302: Zero surface burn rate

How does that stuff look? There should be enough in there for multiple layers too...


I was also thinking, if you lined the bottom edge with aluminum tape it will probably help protect the stuff from direct flame off the side of the pot.

 

[Sheaffdogg]

http://cgi.ebay.com/ebaymotors/ford...016QQitemZ260223072567QQrdZ1QQsspagenameZWD1V

FIRE RATING: Class A/Class 1
MOTOR VEHICLE SAFETY
STANDARD 302: Zero surface burn rate

How does that stuff look? There should be enough in there for multiple layers too...


I was also thinking, if you lined the bottom edge with aluminum tape it will probably help protect the stuff from direct flame off the side of the pot.

If you check the contact temperature range (which I didn't do the last time) it lists a max contact temp of 180 degrees. The tape will protect the bottom from the direct flame, but the 212 degree pot of boiling wort is what melted my last blanket. The walls of my SS pot are pretty thin, so that may have had something to do with it as well.

Maybe if I wrapped the pot first with an old towel, that would provide enough of a buffer for the insulation. Yeah, I'll give that a trial run this weekend.

 

[balto charlie]

If you check the contact temperature range (which I didn't do the last time) it lists a max contact temp of 180 degrees. The tape will protect the bottom from the direct flame, but the 212 degree pot of boiling wort is what melted my last blanket. The walls of my SS pot are pretty thin, so that may have had something to do with it as well.

Maybe if I wrapped the pot first with an old towel, that would provide enough of a buffer for the insulation. Yeah, I'll give that a trial run this weekend.

I think Flyguy uses an electric stove. Is your stove electric? Gas flames are much hotter than 212F wort so your insulation might also be getting a little flame action.

 

[FlyGuy]

I do use an electric stove, and the insulation has more or less held up. But after a four batches, it is starting to deform and the insulation isn't as thick as when I started. I am going to have to find something a little more heat resistant, too -- especially by next month when we move to a gas range instead.

I think this is the next stuff I am going to try to get my hands on. It is similar to what David recommended earlier in the thread, which is some type of automotive-application reflective insulation that withstands heat better.

http://www.amazon.com/dp/B000BHIBHQ/?tag=skimlinks_replacement-20

I can't find the R-value on it, but it looks decent from the photos (probably at least as good as foil-bubble insulation). More importantly, it can withstand high temps (over 250 degrees F according to the manufacturer's website).

 

[Bobby_M]

Wrap the pot with this first:
http://www.infraredheaters.com/insulati.htm

hold it with a little masking tape...
then spray it all down with some 3M Super 88 adhesive and carefully wrap aluminum flashing around it like this stuff:
http://hardware.hardwarestore.com/27-104-flashings/aluminum-flashing-252320.aspx

You could probably figure out some kind of closure method that would allow removal for cleaning the pot. Snaps maybe, or short machine screws/nuts. Think of the thing as a jacket for your pot.

I'm likely going this route to insulate my keggle based HLT and MLT and I want it to handle a raging direct flame if necessary. The cermamic batting is rated to something like 2300ºF.

I also like this stuff but I haven't received an answer as to it's durability in an exposed installation situation:
http://www.avsind.com/insulation.html

 

[FlyGuy]

Interesting idea, but it really is important to be able to take the jacket off the pot to wash and clean it (it is a boil kettle and they do get filthy). The Reflectix jacket I described was great for this because it just slipped right off. Your suggestion would work, but it would be less elegant to remove for cleaning.

I don't think fibre insulation would be a great material to use in this application because inevitable boil overs or spillage are going to soak into it. I really think closed-cell heat-resistant foam, or a sealed insulation product (like the Thermo-Tec product above) are the way to go -- you can make them resistant to spills from the kettle, and they are pliable enough to make a jacket that can be easily removed. Plus, they are designed to reflect radiant heat -- I am not sure that aluminum flashing would do as good a job.

 

[Bobby_M]

I'm only suggesting adhering the batting to the aluminum flashing and not to the pot. For your application on an electric stove, or any electrically heated vessel for that matter, the temp rating only has to be just above boiling. In a direct fired vessel using gas, it needs to do a lot better like near 600F. I'm looking into getting a removable blanket fabricated that will put coated silica fabric around a core of needled silica felt. I know the quote is going to come back $200 per keg... Grrrr.

 

[FlyGuy]

That sounds like an excellent solution for your application. The cost is a bit on the high side, but it would definitely last the lifetime of your gear.

Regarding stovetop pots, I am moving to a gas range soon, so I will have to abandon my Reflectix jacket. I am hoping I won't need it, but the Thermo-Tec material (above) would be a very cheap and easy improvement, even for a gas range (I am hoping). Just gotta find the exact specs on this stuff.

Cheers!

 

[balto charlie]

I really think closed-cell heat-resistant foam, or a sealed insulation product (like the Thermo-Tec product above) are the way to go -- you can make them resistant to spills from the kettle, and they are pliable enough to make a jacket that can be easily removed. Plus, they are designed to reflect radiant heat -- I am not sure that aluminum flashing would do as good a job.

There is an ultralight backpacking stove called jetboil.
http://www.jetboil.com/Products/Cooking-Systems/Personal-(PCS)
The aluminum pot sits directly on an intense flame AND is wrapped in a closed cell jacket. You can pick up the pot of boiling water with your hand and feel NO heat. Very well insulated and able to withstand really high temps. Might give them an email. Or maybe you already have the stuff.

 

[FlyGuy]

There is an ultralight backpacking stove called jetboil.
http://www.jetboil.com/Products/Cooking-Systems/Personal-(PCS)
The aluminum pot sits directly on an intense flame AND is wrapped in a closed cell jacket. You can pick up the pot of boiling water with your hand and feel NO heat. Very well insulated and able to withstand really high temps. Might give them an email. Or maybe you already have the stuff.

I am thinking that might be a weeeee bit small for a boil kettle.

Seriously, that's cool stuff. I wonder if you can obtain the same thing for a pot. Sounds ideal -- thanks!

 

[balto charlie]

I am thinking that might be a weeeee bit small for a boil kettle.

That stove is for brewing 1 bottle at a time

 

[Bobby_M]

I know the thread died, but this looks really promising for you electric brewery guys:

Mcmaster.com
9349K2
Foam Rubber Insulation Plain Back, 1/2" Thick, 36" X 48" Sheet, Black
In stock at $18.88 Each

This is enough to do two sanke sized kettles 18" high by 48" around. A little high temp duct tape at the seam and you're golden... remove it when you want to or not..

Ultra-Flexible Foam Rubber Insulation

Fiberglass Faced
Temperature Range: Uncoated Plain Back, -20° to +220° F; Uncoated Adhesive Backed, +20° to +180° F; Fiberglass Faced, -297° to +220° F
Heat Flow Rate (K-factor): 0.27 Btu/hr. x in./sq. ft. @75° F
Density: 3-6 lbs./cu. ft.
Color: Uncoated, black; Fiberglass Faced, black with silver jacket
Wrap this foam insulation around ducts and large diameter pipes—it's moisture resistant and extremely flexible and soft. Insulation is made of closed-cell elastomeric Buna-N/PVC foam. Cut with a knife. Meets ASTM E84 25/50 for flame and smoke. Size is 36" x 48", unless noted.
Install plain back insulation with contact adhesive (sold separately below).
Uncoated insulation is for indoor use; can be used outdoors if coated with latex paint (sold separately below). Fiberglass-faced insulation is impregnated with aluminum for impact resistance. Use indoors and out.

 

[TheFlatline]

Wrap the pot with this first:
http://www.infraredheaters.com/insulati.htm

hold it with a little masking tape...
then spray it all down with some 3M Super 88 adhesive and carefully wrap aluminum flashing around it like this stuff:
http://hardware.hardwarestore.com/27-104-flashings/aluminum-flashing-252320.aspx

You could probably figure out some kind of closure method that would allow removal for cleaning the pot. Snaps maybe, or short machine screws/nuts. Think of the thing as a jacket for your pot.

I'm likely going this route to insulate my keggle based HLT and MLT and I want it to handle a raging direct flame if necessary. The cermamic batting is rated to something like 2300ºF.

I also like this stuff but I haven't received an answer as to it's durability in an exposed installation situation:
http://www.avsind.com/insulation.html

Having blacksmithed and built my own forge, durablanket is the dog's nuts of insulation. Imagine a fire so hot that half inch rebar will heat until glowing bright orange in about 4 minutes, and yet you can hold your hand on the outside of the forge body without burning yourself.

Yeah, it's that good.

You'd probably only need about 2 running feet of durablanket, which is pretty cheap. If you want to go hog-wild and cost isn't an issue, you would make the sleeve a little (maybe 1/8th of an inch) larger than needs be and then slide it off of the pot. Then you take ITC-9000 and coat the inside of the sleeve, and let it dry for a few days. ITC-9000 is an industrial refractory coating, and is 98% efficient in reflecting (not absorbing, it's not an insulator, it's a reflector) all IR. It's about 35 bucks a pint, and you'd use most of the pint in the project, so as I said, if you wanted to be hog wild and cost wasn't an issue it'd work fantastically.

 

[WDC]

I'm trying to full boil on a gas stove and I've hit the same 'simmer-no-boil' point. Did the thermo-tec (or the durablanket) work out for you, Flyguy?

If not I guess I'm looking at electrocuting myself while building a heatstick. Outdoors just isn't an option where I am so it's that or stick with two pot boils.

 

[sirsloop]

I'm going to try to cover the bottom and top of the 180° aluminum insulation stuff with aluminum roof flashing, and tape that together with with aluminum tape. I dont think I have ever written aluminum so many times in one sentence. It *should* help out, time will tell.

 

[Kauai_Kahuna]

I tried out this setup with an electric stove, and what I did was folded up tinfoil to cover the bottom 3 inces or so inside and out on the bottom, I also rolled up tin foil into "sticks" and line the side of the pot with around 4 of them between the sides and wrapped reflectix. The idea is to keep the reflectix from direct contact with the hot sides of the pot, and allow some air to keep it from going over 180F.

Only did one full boil with it, but it seemed to have come through it OK, I may bump up the number of sticks to 6 or so, and also put a upper wrap of tinfoil on the top to make it easy to clean if I have a boil over.

 

[balto charlie]

hey folks: I have recently 'studied' ultralight weight backpacking stoves. They have done the most w/ the least. Below is an example of a stove using a "cone" to enclose the flame/stove AND pot. This looks like an easy gas or electric stove top solution. I would think a thin piece of aluminum/cooper/ss flashing would work. Make some air holes in the bottom and narrow the cone as it nears the top encasing all of the heat. I believe they decreased the time it took to boil water in half. The Caldera cone in the link is one of the best examples. I shall play and around with this at the next stovetop brewing day. Charlie
http://www.traildesigns.com/products01.html

 

[Revvy]

I shall play and around with this at the next stovetop brewing day. Charlie
http://www.traildesigns.com/products01.html

Keep us posted, I'd be interested in your results.

 

[conpewter]

The cone idea would also be interesting to try with an outdoor propane/natural gas cooker, but I don't want to side-track this thread. If I try it out I'll start one about it.

 

[WDC]

Hey Balto Charlie, I'm giving the chimmney idea a juryrigged shot right now (I'm taking the day off from life to make a sweet stout).
Just using tinfoil wrapped in a cone around the gas burner and base of the pot with small air channels at the top and a gap at the bottom. So far it's got 5 gallons up to a, lid-on, hard boil which wasn't possible before. I think you've got something there. I'd really like to hear how it works for you using better equipment.

 

[Bobby_M]

I know that in BTP (that's beer tools pro for those who don't know), they have you calibrate the effective BTU/KWH of your burner by putting a measured volume of water in the kettle and timing how long it takes to get a 18ºF temp rise. It would be nice to do it twice with/without the side cone. I think a converted Sanke is somewhat already doing this due to the bottom skirt but I don't doubt an added benefit of the cone. Ideally it would go all the way from the top of the kettle (where it touches the sides) all the way down passed the bottom but not far enough to block the air intake. You def want a place for the combustion gasses to escape the cone though.

 

[sirsloop]

Ok... Here's the dealy. I just got a new 40qt stock pot in and successfully boiled 6 gallons of 1.050 wort with it on a crappy gas range in a 750sqft apartment. I made up a little wrap thingy of my own and it held up GREAT!

So I got this insulation stuff off Ebay, but apparently it can only hold up to 180°F. When I got it I was bummed cause there was what looked like weak plastic on the inside. I knew this would not hold up to any kind of direct flame so I made a Lowe's trip with the intent to armor up. Cost was 19.99 and there's enough for AT LEAST another pot.

http://cgi.ebay.com/ebaymotors/ws/e...STRK:MEWN:IT&viewitem=&item=260223072567&rd=1

So I grabbed a 14"x10' roll of aluminum flashing from the roofing section (over by lumber). I also got a roll of aluminum backed tape from the duct section. That was like 13 bucks or something like that. There's an enormous amount of tape and enough flashing to make two pots.

I got back home and made two wraps around the pot with the insulation stuff. I used the aluminum tape on each one individually and worked them together with the seam staggered. This should be a little stronger and hold shape better than just wrapping it up and taping the ends together. I measured and cut out a 14x49" long piece of flashing. I folded over the bottom 4 inches of the flashing making a 10x49" piece doubled on one end. I used scissors to cut the 4" section perpendicularly every ~3" so you can still bend the flashing. I wrapped the 4" sections up around the inside of the pot, taped the inside edge to the insulation. I worked on one little part at a time until I made it all the way around taped. Then I went around the top, making sure that all of the inside insulation was covered with tape. This should give a little added protection for the insulation. I went down the outside edge of the flashing with the tape and called it a day. So its basically two wraps of insulation, the outside completely covered with metal, the inside lower 4" covered with metal, and the inside top 6" covered with aluminum tape. Check it out.

The sleeve fits pretty snug but I found that the heat loosens it up a little so I first tried taping it up. The tape works ok, but it wasn't safe enough to walk away from. I had the tape come off once and the sleeve got some direct flame for 20 seconds. See the scorched section on the bottom there. SO. I just cut a little piece of scrap flashing and make a little prop to physically hold up the sleeve. Its simple and very effective.

I'm not sure how well it worked cause ive never boiled without it. It took 6 gallons of wort from ~160°F to 210°F in 25 minutes on a gas stove. Not too shabby.

There are still improvements to be made!! There is a lot of heat loss off the edges of the pot where the burners are. I'm thinking about getting some angle iron from the depot that will stand up to direct flame and use that to block the flames from shooting out the side. That should improve overall heating and prevent scorching of the pot.

enough rambling for now...