"Bloom" is a strength of gelatin. When the bloom is higher, the moose gets firmer. And when the bloom is lower, the mousse gets softer. And the bloom ranges from 50 - 300 or 350 usually. Today, I used this gelatin sheets with 230 bloom. So, that means the texture will be softer when you use gelatin with a much lower bloom, even if you use the same amount as the recipe. Check your gelatin, compare it with the bloom I used today (230), and see if it's about the same or overly different. I live in the States, and the most popular gelatin you can get anywhere at the grocery stores is gelatin powder from Knox. And I came to find out that the bloom is 225, which is so close to my gelatin sheet! I was so excited to share that with you. If you have your favorite gelatin, check if it's listed in the package. and if it doesn't, see if the website says anything about it.  If you can't find it anywhere, make it one time and decide if you should reduce or add more gelatin next time.