What is gelatin mass?
Gelatin mass consists of two ingredients: gelatin and water. The ratio is usually 1 to 5 times its weight: i.e., 1 part gelatin to 5 parts water. For example, if you are using 10 grams of gelatin powder, you would use 50 grams of water to hydrate the powder to make the mass.

Why use gelatin?
Gelatin is used to give texture to food items like gummies and marshmallows, or to set various products like mousse, or other aerated creams.

What is “gelatin bloom strength”?
There are various types of gelatin (gold, silver, bronze, …) in terms of bloom strength. These different strengths are available as powders but also as sheets.

Platinum: 235-265 bloom, 1.7g per sheet
Gold: 190-220 bloom, 2g per sheet
Silver: 160 bloom, 2.5g per sheet
Bronze: 125-155 bloom, 3.3g per sheet
Titanium: 100-125 bloom, 5g per sheet

Bloom refers to a test that measures the strength of a gelatin. The test essentially measures the weight required to smoosh the gelatin by a certain amount. A higher bloom value indicates a stronger gelatin, it also indicates a higher melting point and a shorter setting time. 

This may all sound a little overwhelming, but don’t panic! If you stumble across recipes that call for a different strength there’s no need to stock up on every type of gelatin, you can approximate the amount required according to the type of gelatin available to you with some simple mathematics. For example, if a recipe calls for 4g of silver sheet and you only have gold 200, you simply multiple the bloom strength by the weight that you are using and divide it by the type that you plan to use. In this instance, you will need 4g x 160 = 640 bloom strength. And divide 640 by 200, giving you 640/200 = 3.2 grams of gold that you can use instead. Basically, the formula is: mass A x bloom A = mass B x bloom B*.

*Note: I haven’t tried it, but Chefsteps suggests an alternate formula: mass A x √(bloom A / bloom B) = mass B

There are many types of gelatin out there, but from teaching at George Brown College, I often get students who ask for an alternative to pork gelatin. Pictured in this post is the fish gelatin from Pastry Wizard, this product is nice because it comes in smaller quantities, which is great if you are not going to be using a ton of it.

Why gelatin mass?
Many recipes call for gelatin sheets or gelatin powder. So why do we like working with gelatin mass? There are two main reasons for using gelatin mass: 1) to make sure that the recipe is more precise and can be followed more consistently, and 2) for ease. When using gelatin sheets or powder, it must first be hydrated (“bloomed”) in cold water. It’s difficult to know exactly how much water is absorbed and then added along with the gelatin. This means that you’ll lack consistency and control over how much water you’re adding. Having gelatin mass pre-made in your fridge also helps to streamline your production. It’s easy to scale and you can skip the step of hydration. For these reasons, I have started converting all my recipes to gelatin mass and now like to keep a container in the fridge. Every time a recipe calls for it, I simply need to take it out of the fridge and scale out the amount I need. If you’re not planning to use it very often, I would recommend making only small amounts at a time, because the gelatin mass has a lot of water and will grow mould fairly easily.

How do you make it?
1. Scale out gelatin and cold water in separate bowls. Sprinkle gelatin powder into cold water, and let the mixture hydrate for a few minutes and cover the bowl in cling film.
*** If some gelatin remains on top that isn’t hydrated by the water (it still looks dry), just mix it in and let it hydrate.
2. Heat the mixture over a double boiler and let it simmer until everything is fully dissolved and the mixture is clear.
3. (optional) I haven’t tried it myself, but I’ve been told that the gelatin mass will become much clearer if you heat it a second time over the double boiler after cooling in the fridge for some time.
4. Let cool, then place it in the fridge for a later use.

Bonus points: How do you convert a recipe that calls for gelatin powder or gelatin sheets to gelatin mass (and visa versa)? Basically, this amounts to reducing the water in the recipe with the water that is added when you make your gelatin mass.

Here are some recipes that require gelatin mass:
Gwai Fa Go (Osmanthus Flower Jelly)
Mirror Glaze
Pandan Panna Cotta
White Chocolate Glaze