So what would it take to boil 16oz of water with this setup?

I checked out a local Aldi's in Connecticut, USA this afternoon. It looks like a surplus store for food. I suspect there is no SET inventory that can be relied upon. Likely, it has whatever foodstuffs that is available in the over-stock type wholesale market.

Conway Yee

Not sure, when it gets chilly again I'll have to do some more testing. While you have a flame there you could supplement the fuel tab with some tinder or kindling.

As it stands, you can store four of the esbit cubes inside a closed stove. There isn't enough room for more cubes, but there is enough room that each of the cubes could have been maybe 10-20% larger and fit inside snugly. I'd imagine that would have at least gotten it simmering in those conditions which is better.

My cubes are several years old though, maybe that made a difference

Did you have a good windscreen? That usually improves efficiency considerably, as does some sort of a lid on the container. I don't think I have ever seen a lid for a GI canteen cup, but one can be easily made from aluminum flashing or even heavy duty foil....

I know of at least TWO lids for a GI canteen cup.

A plastic lid:
http://www.bestglide.com/canteen_cup_lid.html

A stainless steel lid : http://www.thekeytosurvival.com/storetitles/stovescookware/heavyboilcover.html

Neither lid is USGI.

It would appear neither lid will fit in a USGI canteen cover along with the canteen, canteen cup and stove. I am sticking with aluminum flashing for this exact reason.

Thanks.
Conway Yee

There wasn't any breeze that I could feel, but the best I had windscreen wise was my legs on either side of it lol. I agree having a lid probably would have helped, and they do make them for the GI canteen cup as Yee pointed out.

I wonder if I should invest instead in a simple alcohol stove, or maybe see what I can do with sterno.

Maybe I am missing something, and for that I apologize, but if this stove cannot be counted on to reliably boil 16 oz. of water, then I'm not going to carry it no matter how small and convenient it is. My primary go to is a Jetboil which is incredibly reliable, but the fuel is expensive and bulkly. A backup stove would also be nice, but I'm having trouble understanding the draw of the Esbit.

I do not use the esbit as a stove, only as tinder to start a fire. I will either cook on a canister fuel stove or a fire.

Military canteen cups are not particularly efficient. Use a Primus Tea Kettle (wide hard anodised aluminium base) and use 2x14 gram Esbit Tabs. Use a wind screen as well such as a titanium foil or the heavier Aluminuim type.

You might just be able to boil enough water (800ml) for a Mountain House and a cup of tea with 2x14 gram Esbit tabs.

From my experience Esbit is more bulky and expensive compared with the Butane/propane cartridges if being used for more than a couple of days.

And Esbit is more reliable than certain gas stoves especially over a wider range of temperatures.

Problems with Esbit or Hexamine stoves are that they are messy and smelly and for the stove to work efficiently they have to be protected from the wind as with the case of alcohol stoves. They are also slow and inefficient compared to something like the Jetboil and they cannot be used inside a tent for example.

Esbit (hexamine) will work reasonably well in sub freezing temperatures compared to other gas stoves (without a liquid feed) and can be useful for the very lightest day hikes where an Esbit stove can weigh as little as around 12 grams and the fuel required around 60-80 grams for a days use. But when you include the windscreen and pot i.e. say a Primus Kettle @150 grams and a Ti windscreen @50 grams - Total Weight would be around 300 grams. A $149 Jetboil SOL ti with a 100gm gas cartridge would weigh around 90 grams heavier.

If you run out of fuel, you could break up the last Esbit tab to use a fire starter and still continue to use the Primus Kettle.

Hexamine stoves are very cheap as well i.e.

http://www.strikeforcesupplies.co.uk/index.php?method=stock&id=2002&from=63

The British Army Tommy Cooker for £3 will boil a Gallon of Water (even with the less efficient Hexamine/wax mixture used). They were usually supplied with a 24hr UK Army Operational Ration Pack which was equivalent to 3 MREs and you could actually boil water for a hot cup of tea. Try doing that with a Chemical heater bag.