*The spice from hot peppers is mostly held in their seeds and veins. This means you can control the level of heat in the soup by removing some or all of these before dicing the peppers.
For a milder soup: remove the seeds and veins and discard them. If you're worried this may still be too spicy for you, reduce to just one jalapeno.
For a spicier soup: leave in some, or all of the seeds. For this batch I de-seeded one pepper and left the seeds in the other, and found the level of heat to be as hot as I would ever want it -- spicy, but not melt-your-face-off spicy. Peppers tend to vary from plant to plant, too, so if you aren't sure, I would say err on the side of caution. If you feel the soup needs more kick at the end, you can always add a dash of cayenne, some red chili flakes, or your favorite hot sauce. (And if you're cooking for people with a range of tastes, you can always make the soup on the mild side and let everyone adjust to their liking at the end.)
Recipe inspired by
this black bean soup from The Pioneer Woman.