How do you get a merangue to stay risen?

Answer 1

If it is sinking before or during the cooking, you have not whipped the egg whites enough (it will take a good 5-7 minutes on high speed with an electric hand whisk in a really large bowl), or you are using too little sugar (at least 50 g per egg white is needed). If it is sinking after cooking, it is probably uncooked.

Also, on the topic of "underwhisked egg whites", you should be aware that the typical hand blending kitchen aids (which come with whisks and milk frothing attachments etc...) are really hopeless at whipping egg whites. They will usually get them to the soft peak stage, but never stiff peaks. For the whisking, a cheap electric hand whisk with 2 beaters will do a far better job than an expensive hand blender with a whisk attachment will. Also, a bowl that is at least 10 times the volume of the egg whites that you're using is necessary, to ensure that there is enough room of air circulation and for the whites to expand. And if the whisk is beginning to warm up, run it under the cold tap and dry it off. Egg whites increase in volume best when using cold/room temperaure utensils (cool bowl, cool whisk etc...)

If you are using uncooked meringue to decorate something, and it is going runny, you should really be using the Italian meringue technique rather than the standard French. Italian meringue involves whisking in hot sugar syrup into the whisked egg whites, which partially cooks the whites. This type of meringue is only used when the finished product gets either a little or no subsequent cooking, such as on a baked Alaska.

If it's Italian meringue which is going flat, you have either not whipped the egg whites sufficiently, or the sugar was not hot enough/did not have all the water boiled off.

Also, after about 4 hours or so, Italian meringue does start to weep liquid - this is not something that can be prevented.