There are a lot of different fuel sources out there for alcohol stoves. Denatured alcohol, grain alcohol, methy alcohol and in a pinch isopropyl (rubbing) alcohol, etc.
Ideally you want as high a percentage of ethanol for the fuel with the lowest amount of methanol as possible. The higher the ethanol to methanol ratio the more clean burning, non toxic, highest heat fuel you’ll get.
I’ve never seen any company list burn times, and few seem to have this info right on the label. But almost every type does have an MSDS sheet that lists this information. For example:
https://www1.mscdirect.com/MSDS/MSDS00053/70250709-20190907.PDF
Here is a list of a few popular brands out there and their percentages:
- Kleen Strip Green DA 80-100% 3-7%
- Jasco Green DA 80-90% <5%
- Startex DA 70-90% 20-30%
- Whitaker ~66% 30-40%
- Jasco DA 42-46% 52.-55%
- Kleen Strip SLX DA 30-60% 30-60%
- Sunnyside DA 30-60% 30-60%
- Crown DA 20-30% 65-85%
- Heet (Yellow bottle)0% 100%
Now at this point many people are going to say that theyve been using Heet for years and it works fine. I’ve used it to and it works OK, but the Kleen Strip green works even better! Check this out for reference:
So ethanol is roughly 20% more energy dense.
This guy tested a bunch too, and even had soot pictures and Kleen Strip came in second for him, though I will note only 15 seconds behind Crown. Given the toxicity of Crown I’ll wait the 15 seconds for the Kleen Strip.