Can I use 3 jalapenos in place of 1 habanero? I once got from the library this big book of Mexican recipes. A lot of them called for habaneros and a few of them called for red habaneros.

My mother suggested that if I see a recipe calling for habaneros that I should use jalapenos instead and even suggested a ratio, 3 jalapenos to 1 habanero.

The reason? Jalapenos have more fruity flavor than habaneros (a lot more) so if I use jalapenos for something with the same amount of heat as habaneros then I will get more fruity flavor for the same amount of heat.

But can I really get the same amount of heat that is in 1 habanero from 3 jalapenos? Or should I change the ratio?
Yes, you can usually make that substitution without a problem. The key thing in substituting peppers is that you like the substitution. So, experimentation is necessary to find what is ideal for you.

Personally, I like the flavor (separate from the heat) of habanero peppers more than I like the flavor of jalapenos, but I usually have jalapenos on hand. So I often make that substitution and then just add crushed red pepper flakes or cayenne to make up the difference in heat because I'm a big-time chili-head. Doing it that way, you don't need to use more jalapenos than you would habaneros, but you can. After all, it's your dish.