Save Fuel Indicator Pasteurize Don't Boil

Thank you Colin. Back to the drawing board. I’ll reformulate and bring the activation point (color change) up to 160 degrees.

Anthrax and botulism (Bacillus and Clostridium) form spores, but those aren’t considered a major risk in most waters (for immunocompetent people). 

I had to look up the definition of that :-)

“Immunocompetence is the ability of the body to produce a normal immune response following exposure to an antigen.”

Yeah, babies and immunocompromised people can get a kind of anthrax from ingesting water that contains the spores, but immunocompetent people generally can’t.

I should add that Ryan Jordan is an expert in this area, I think. If he decides to chime in, and he disagrees with anything I’ve said, take his view.

How much heat will you lose by lifting the lid multiple times to look at the indicator?

A bi-metallic strip has the potential for mechanical actuation – but then you’re adding more weight with this gadget.

Maybe you could put the ink on a thin strip of plastic, or use a segment of an adhesive thermometer, and dunk it through a slot cut in your lid.  That would probably amount to zero weight gain and negligible heat loss checking the temp.

You can pretty accurately determine temperature by sound.  Wait till it starts getting noisy, then open lid and look at sensor.  After a time or two you’ll know what it sounds like.

Wouldn’t that change with altitude?

So if you know the sounds of your pot, and you have a thermometer, you can earball your altitude…

If you can hear the noise, you don’t need a visual Indicator ;-)

160 occurs long before the noise.

Yes, water’s boiling point decreases at elevation.  Very close to 1F for every 500 feet of elevation.

At 7,500 feet, water boils at about 198°F.  At 10,000 feet, 193°F.

I just use a pot lid of Wood’s Metal (Bismuth, Lead, Tin, and Cadmium).  I know instantly when the water reaches 70C / 158F because the alloy melts and falls into the pot.  I try not to think about how toxic those metals are.

ha, ha, good one…

what is it, maybe 10 F drop in boiling point per 5000 feet of elevation

you could just “earball” that, let it get a little louder or let it go another 30 seconds, then open lid and look at sensor.

I have some of these 145 degree WAPI water temp indicators available. If anyone is interested I will put a listing in Gear Deals on Monday. Cost 25 cents each + $4.00 shipping.

An option, if you wanted to aim for 160F but had those 145F disks, you could look when the sound started to change, confirm the 145F disk had changed color, replace the lid, and then give it an additional 10 count for a cup or 20 count for a pint.

Note that tossing a cozy over the pot and letting it sit for another few minutes uses no fuel and increases your kill ratio, whatever temperature you’ve achieved.

I’ve been working on a new design of a device for solor cooking. It floats on top of the water being heated. It is made of food grade plastic, has 2 temperature ranges, 150 degrees and 170 degrees. Both temperatures are used to determine levels of pasturization. The 150 degree indicator is going to be nice to determin the right temperature for a good hot cuppa coffee or hot chocolate.
The temperature discs are the size of a half dollar and weigh 4 grams. Inside the disc is a color changing strip that has 2 round discs that are black in color when not being in contact with heat. When the disc is being heated and reaches 150 degrees the one disc turns red in color, as the temperature increases to 170 degrees the other disc turns red. Let the water stay at that temp for 1 min. and we have reached a pasturization point.

Here are two video links that show me testing the seal of the plastic discs. I heat them to boiling, let them boil for a min. and let cool. One video will show how the 2 round internal discs turn red when heated, the other video shows how the discs return to the black color when removed from the water. They are short videos but will give you an idea of how discs work as a visual aid in determining what the temperature of your solar heated water is. Watch closely as the discs turn color:

https://photos.google.com/share/AF1QipOraMCnMbCl_UMXLfi3ftwhXIZ5UNncNrmyYd_QcmZQfk9r4hbUhKAZBqyxX1dX-A?key=UTlvZFdyWHdIeDRVcWR4bTZ2SzdZMkwtTG9CN3RR

https://photos.google.com/share/AF1QipOyHe-1vwC0jp2t4g-fVQhehZ0spLNYXEO_fp7bU6cRiPP4jZBNL81bAFHc-qZebQ?key=NEluZzloek1vMDREczlWajA2OVhjN3JzbGk4cFhR

I redesigned the Paturization indicator. Slimmed it down, made it lighter ;) I even have one that goes up to 170F.

Dan,

Are you selling the improved temperature indicating disks?

Dan,

Are you selling the improved temperature indicating disks?

I could have a listing put up by Friday. Are you interested in the single temp or double?

Practically I think I would only use the 170 degree, but I would buy one either way

I’ll send you one of each. Give me your address in a PM

Bump for reference.

nm

jscott wrote:

“Note that tossing a cozy over the pot and letting it sit for another few minutes uses no fuel and increases your kill ratio, whatever temperature you’ve achieved.”

Yeah, I’m with the notion of listening, then looking for steam and the bubbles just before a roiling boil–and then shutting things down and letting the heat kill anything left over. For heaven’s sake, can’t we trust our experience anymore? We’re not out doing fine tuned experiments in the lab. We’re making oatmeal for breakfast and a little coffee.

 

In that video he identifies a bunch of sources of information to verify that 160 F for 15 seconds works for parasites found in the wild.  I forget what the numbers are, but something like 150 F for 5 minutes – the time goes way up for small decrease in temperature.  And who can wait for more than 15 seconds???

You can’t determine this by experience.  There’s a low probability of getting very sick.  You don’t want to be on the margin of safety and occasionally get very sick.  Somebody has to do a large study of hikers, and looking at water with a microscope or trying to culture it – sciencey stuff.

Dan’s post from 2017 is pretty complete – no need to watch gear skeptic video : )

Dan’s post from 2017 is pretty complete – no need to watch gear skeptic video : )

Nobody remembered this thread :-( It was all for naught.

Dan: an interesting turn of events. I deleted my own post because I thought it might be taken as discounting the work and product that you were offering. I realized there may be real world applications for your indicator that would be helpful for folks. And then you somehow resurrected my deleted post…without comment! Wow, you’re a man after my own heart, clearly a free speech advocate even when it seems contrary to your own interests. Kudos! and indeed your indicators could really be applicable in a lot of different scenarios.