All You Need to Know about Sheet Gelatin

Very Soft Custard, unsuitable for a large tart

In my last post, I had created some lovely 4-inch individual tarts filled with a soft custard. This custard was far softer than I had hoped, and would not have been usable for a larger tart. And this got me thinking about what filling I would use if making a larger tart.

I have a most excellent Chocolate Mousse recipe that could not be any more simple. No cooking involved and it takes only minutes. Granted, it uses unsweetened cocoa powder. White chocolate doesn't come in "cocoa powder" form, so how then would I accomplish it? Could there be an easy and simple method for white chocolate mousse? I read through a dozen or so "easy" white chocolate mousse recipes. My regular chocolate mousse uses gelatin, and it sets just nicely so that it is creamy in the mouth, and without the feel of a gelled substance. I wanted to accomplish this, and wanted to err on the side of caution in how much gelatin was used. It needed to be just enough to make it hold its shape when piped; nothing more.

One of the recipes I read used sheet gelatin. Which got me thinking.

Sheet Gelatin

I bought some sheet gelatin about a year ago, but never got around to trying it out. I do not make gelatin based desserts or gelled anything, very often. I had seen sheet gelatin used in TV programs. I had seen it called for in some few recipes. Due to all these programs, finding sheet gelatin is now far easier than in the past. But in all my years, I had never once seen it or tried it, so I did some research. 

Two Sheets of Gelatin

Sheet gelatin comes in - well - sheets, or leaves. They are crisp and thin and just like with powdered gelatin, need to be "bloomed" (hydrated in cold liquid for about 10 minutes) before using. Once bloomed, they need to be dissolved in hot liquid before using, yet not boiled. In using powdered gelatin, when blooming in liquid, this liquid (now absorbed in the powdered gelatin granules) must be taken into account along with the whole amount of liquid in the recipe. Using sheet gelatin, it must be bloomed in cold liquid also, but it is them removed from the cold liquid and added to the hot liquid to dissolve. Therefore, the cold soaking liquid gets tossed away and is not counted in with the whole recipe's liquid amount.

The biggest difference is that sheet gelatin comes in differing strengths, requiring more, or less, sheets to accomplish the same thing. The four strengths are Bronze, Silver, Gold and Platinum. Bronze has the least gelling power and platinum has the most gelling power, per sheet. However, you must really use the sheets by weight, to calculate the amount of any of the sheets to use in substitution for powdered gelatin. Some recipes will specifically tell you which strength to use, but many will not. If there is no suggestion, then opt for Silver, which is possibly the most commonly used. 

There are also guidelines to each category's bloom strength and weight per sheet. 

• Bronze: 125 - 135  /  3.3 grams by weight
• Silver: 160  /  2.5 grams by weight
• Gold: 190 - 220  /  2.0 grams by weight
• Platinum: 235 - 265  /  1.7 grams by weight

Granted, this seems useless information, without anything to compare it with. Then I read somewhere that a packet (about 2½ teaspoon worth) of Knox gelatin weighs 7 grams. And then I got it. I got how I could compare what a particular sheet or sheets would do in comparison. Now this information made sense. One envelope of powdered gelatin will softly set 3 cups of liquid, medium set 2 cups of liquid or very firmly set 1 cup of liquid. One Platinum sheet, according to my package will set ½ cup liquid. Use more, or less, to accomplish your goal.

How Can I Substitute Powdered Gelatin with Sheet Gelatin?

Ultimately, it doesn't matter which grade of gelatin sheet you acquire, all that is needed is an adjustment in how many sheets to use, by weight. If a recipe calls for one whole packet of powdered gelatin (which is 7 grams total), then I can substitute:

• 2¼ sheets Bronze to equal 7.4 grams
• 2¾ sheets Silver to equal 6.9 grams
  
• 3½ sheets Gold to equal 7 grams
• 4 sheets Platinum to equal 6.8 grams
  

At least, this is my own, personal calculation by gram weight. It is not 100% accurate, but should be quite close. Err on the higher side for more firm setting, or lower side for softer setting.

White Chocolate Mousse, soft set

When calculating the amount of gelatin for my white chocolate mousse, knowing I wanted the mousse to set and hold its shape, once piped into little shells, yet not have the completely firm "set" and mouthfeel of "Jello," I calculated on the low side. I wanted to give the whipped cream element a boost, so to speak, not to make it unmovable. My white chocolate mousse recipe uses approximately 1½ cups liquid, and uses 1¼ teaspoon powdered gelatin, or 3.5 grams. I would need to approximate that using the sheets. Considering that my Platinum sheet package states that each sheet will set ½ cup of liquid, I would look for a very soft set for a little over 3 times that much liquid and use half the 3+ sheets, going for lower setting power. I used 2 sheets (total 3.4 grams).

Why Use Gelatin Sheets at All?

Gelatin sheets have been mainly used in the domain of the professional kitchen. Until more recently, with all the wonderful TV programs out there, with their attendant cookbooks, and calling for sheet gelatin, it has become much more widely available. The main difference between sheet gelatin and gelatin powder is that the sheets have far less of a flavor and gelatin made with them comes out far more clear. If your goal is perfect clarity in your gelled substance, without any off flavor interfering, then sheets are what you want. Powdered gelatin has a definite flavor and does not yield such a perfectly clear outcome. 

If what you want to set is opaque and highly flavored, then it makes little difference which type of gelatin is used.

What is Gelatin?

One Packet of Powdered Gelatin
 in a tablespoon measure

Gelatin comes from collagen, found in animals. Most commonly, gelatin is extracted from pig skin, though bovine gelatin (from skin or hooves) is also widely available. There is no true "gelatin" other than what comes from animals, although there are good vegan gelling agents, such as agar. This means that anything made with gelatin is unsuitable for vegetarians or vegans. Knowing dietary restrictions will also determine the type of gelatin to be used, whether porcine or bovine.  

As mentioned above, gelatin must be bloomed before using. This means it needs to be soaked in a cold liquid to hydrate, or "bloom" and then dissolved and melted into a hot liquid. Under no circumstances should the hot mixture be boiled once the gelatin has been added, as this can result in unreliable setting ability.

Gelatin Inhibitors

Knowing about how to use gelatin does not mean it is going to work like magic on any liquid. There are various things that can cause the gelling action to fail.

Many fresh fruits have an enzyme that inhibits gelatin's ability to set. These fresh fruits include pineapple, papaya, kiwi, peach, mango, guava and fig. Once cooked though, these fruits cause no more problems, as you may have seen if you've ever been exposed to Jello made with a can of fruit cocktail in it. Other things can also inhibit gelatin from setting: 

• too high a temperature and prolonged heating (as noted previously), 
• too high an alcohol concentration (above 40%), 
• too high an acid content to the liquids to set, or 
• too high a salt content.

Gelatin will set if the liquid is within a pH range of 4 to 10 (7 is neutral pH). Citrus is acidic and if the citrus content is too high, your gelatin will not set. The same goes with too alkaline a liquid.

One last thing of importance is that gelatin needs to be chilled to set completely, preferably 6 to 12 hours or more at below 59 degrees F.

Gelatin Strengtheners

Sugar and cream help gelatin to firm up. Sugar pulls liquid out of the gelatin and cream is thicker on its own, aiding the thickening process. There is also a commercial setting promoter called transglutamase.

I hope this article is not too confusing, and that it may help you tread these strange waters with more ease and confidence. My White Chocolate Mousse recipe, coming soon, will be using gelatin sheets, so this article may help prepare for it. 



My passion is teaching people how to create a harmony of flavors with their cooking, and passing along my love and joy of food, both simple or exotic, plain or fancy. I continue my journey in ethnic and domestic cuisines, continuing my journey to explore diverse culinary experiences and hopefully to start you on a journey of your own. Join me also at A Harmony of Flavors on Facebook, and Pinterest.