My girlfriend is vegetarian and we have been trying to make marshmallows at home but so far after over four tries with agar agar we have yet to be very successful. We have made one batch that were tasty - but too dense to really be marshmallows (but sweet and we coated them with roasted coconut so they were quite edible) but our other tries have resulted in gooey, sticky not very tasty concoctions.
So what are the secrets to making vegetarian marshmallows at home?
This is definitely one of those times where I wouldn't recommend substituting agar for gelatin; it's simply far too stiff for marshmallows.
If you can get hold of some methyl cellulose, it works great for marshmallows. Unlike other gelling agents, methyl cellulose hydrates in cold water and sets when heated, so you can roast it with direct heat and it will still hold its shape. All you need is methyl cellulose, vanilla, sugar, and water.
You can find the full recipe at playing with fire and water (see "methocel marshmallow", second on the page).
Try using mallow root. It is where the confection got its name, and is the very ingredient that has been superseded by gelatin.
You can buy vegetarian gelatin quite easily I believe. One thing to be careful of is the amount, as sheets of gelatin vary in size; I made some marshmallows a while back that called for 12 sheets, but the ones I had were half the size of those used by the recipe author.
Also, leave them to set overnight, regardless of what the recipe says, or it will be like trying to pry week-old gum out of the pan!
