Chances are, unflavored gelatin isn't something you think about very often, except when grabbing some Knox powder at the store. And, for the most part, that's a-okay; when used exactly as directed, gelatin's a pretty straightforward thing. But the more you bake, the more likely you are to venture outside the box and experience some sort of mishap. Say, a rubbery panna cotta, sticky marshmallows, or a droopy chiffon pie.
It's absolutely maddening to stare at a recipe and have no idea what went wrong, especially if it seems you followed the directions to a T. Having worked with sheet gelatin in restaurant kitchens and powdered gelatin at home for the better part of my life, I've witnessed more of those trials and tribulations than most. That has led me to realize that these failures aren't random, and that some pretty benign circumstances may create problems for gelatin.
What Is Gelatin?
Let's make sure we're all on the same page here first. Gelatin is a protein extracted from animal sources. Bloomed gelatin is melted and incorporated into a dessert, dispersing little molecules of protein throughout. As the gelatin cools to below 100°F, those molecules begin to interlink, reorganizing themselves into a three-dimensional net, with water caught inside. That reduces a dessert's ability to flow, giving mousse or panna cotta a relatively firm texture despite a high proportion of liquid ingredients.
Many of gelatin's most surprising quirks are side effects of its manufacture. Contrary to urban legends, gelatin doesn't come from hooves (which are made of keratin) but from collagen-rich hides and bones. While gelatin can be made in a number of ways, from a commercial standpoint, we're talking mostly about pork hides and cattle bones—disparate sources that require different processing techniques. An acid treatment for hides, and an alkali treatment for bones.
As with olive oil, multiple rounds of processing can extract several different grades, the first being the finest. This sort of gelatin is valued for its light color, mild flavor, and high molecular density, a measure of its strength. With each subsequent extraction, the resulting gelatin is darker, meatier, and less dense (i.e., weaker). As a general rule of thumb, porcine gelatin tends to be lighter in color but more aromatic, while bovine gelatin is darker but less fragrant.
After extraction, these various grades of porcine and bovine gelatin can be blended individually or with each other in exponential ways, then processed into granules or sheets. All those variables mean that gelatin's color, flavor, aroma, and strength can differ considerably from country to country or even brand to brand.
In and of itself, that's enough to explain why an American might have trouble adapting a French recipe (or vice versa), and why fancy restaurant desserts don't always turn out so well at home. It's also the reason why a seemingly innocent switch from one gelatin to another might be the source of all your woes. Beyond that, there are a number of other variables that can provoke gelatin to behave in unexpected ways. Here are six of the most pernicious, and what to look out for.
Issue #1: Bloom
The Scenario: A recipe calls for a specific type of gelatin, but it's not what you have on hand. Who cares; protein's protein, right?
Well, not really. Gram for gram, gelatin's mostly protein to be sure, but by blending different grades, manufacturers create a mix of proteins that behaves in a very specific way. Its behavior is expressed in terms of bloom—an obscure measurement of gel strength ranked on a scale of 0 to 325. As you might expect, the higher the number, the stronger the gelatin, but textural differences come into play as well. I'm not quite ready to start unpacking the mechanics of molecular density and interlinking protein chains, but high-bloom gelatins result in a tender gel, while low-bloom gelatins produce one that's gooey. So, while you can use more of one type or less of another to create a similar strength, you can't always re-create the mouthfeel of a particular gelatin. (Imagine a stretchy panna cotta, or a gummy bear that breaks like Jell-O.)
The Danger: Without taking into account differences of bloom, your recipe may be doomed from the start. The best way to avoid trouble is to hop online and buy the exact sort of gelatin a recipe calls for. If you're whipping up a dinner-party dessert and don't have that kind of time, it's important to realize that a rough 'n tumble substitution is no guarantee of success.
While bloom strength is rarely printed on the box, all you need to know is that powdered gelatin is formulated to an industry standard of about 230 in America and 250 in Europe, creating some unspoken implications depending on the citizenship of a recipe. Sheet gelatin is a little more complicated because it's sold in strip-club membership tiers (bronze, silver, gold, and platinum) that represent not specific bloom strengths but a range. For example, platinum gelatin can be anything between 235 and 265 bloom, so unless you match a recipe brand for brand, your results won't necessarily be the same.
Any recipe you find on Serious Eats is tested with Knox gelatin in mind, and, because I happen to have a pork allergy, my desserts are cross-tested with bovine gelatin as well. Ounce for ounce, my favorite brand costs a fraction of the price of its supermarket counterparts, and has a far milder aroma as well—bad news for savory applications, but great for dessert.
Issue #2: High Heat
The Scenario: For some reason, your marshmallows keep turning out gooey and strange, even though you followed the recipe precisely. What gives?
Back-of-the-box directions that call for boiling water give us the impression that gelatin is impervious to heat, but boiling simply represents its upper limit. Gelatin's strength rapidly declines above 212°F, or when it's held at that temperature for an extended period of time. Curiously, damage caused by heat impacts rigidity, not viscosity, which explains how gelatin can still add body to slow-simmered dishes like Bolognese. If sufficiently concentrated, even weakened gelatin can have remarkable power (as in a hyper-reduced veal stock turned glace), but that has no bearing on dessert.
The Danger: Unfortunately, few recipes will warn you of gelatin's vulnerability to heat (a reality compounded by the presence of acidic ingredients), so, without a cooling period, you may stumble into trouble unawares. This is particularly true of marshmallows, which involve a sugar syrup cooked to an excess of 250°F. Whether the recipe says so or not, it's best to let the syrup cool to about 212°F before adding the gelatin, or else the candy may have an unpleasantly soft or gooey texture.
Issue #3: Strong Acids (Low pH)
The Scenario: You've found a great recipe for lemon mousse that calls for Knox or kosher gelatin, but you've converted to another type or brand. Even though you were sure to account for bloom, something went wrong. Is the recipe a dud?
Maybe not! While recipes never specify bovine or porcine gelatin, any recipe that calls for Knox was formulated with the power of a blend. Meanwhile, kosher or halal recipes almost certainly use bovine (piscine, in some rare instances). Many other brands are strictly porcine, especially when it comes to sheet gelatin or powders sold in bulk online.
The Danger: The acidic treatment used to denature the collagen in animal hides leaves porcine gelatin vulnerable to solutions with a pH of 3 or below—on par with distilled white vinegar. Most desserts aren't that acidic, but ingredients like lemon, lime, passion fruit, rhubarb, and even pomegranate are. If the directions bring juice and gelatin into direct contact, extreme acidity creates a perfect storm of circumstances in which shifting from one type of gelatin to another may cause trouble, particularly in recipes that call for only a small amount of gelatin, like panna cotta or mousse. (Gelatin's vulnerability to acid can be overcome with sufficient concentration, as in gummy candies.)
If a recipe bothers to mention a specific brand or type of gelatin, it may be with good reason! That might not always be the case, but knowing that acidity can constitute a red flag when it comes to gelatin can help you avoid problems with an unfamiliar recipe.
Issue #4: Alcohol and Enzymes
The Scenario: You've found a recipe that calls for gelatin to be bloomed (hydrated) in vermouth, but that's not really your thing, so you decide to try a different liquor or fruit juice instead.
The Danger: Switching things up with the blooming liquid may seem like a creative opportunity, or at least a harmless swap, but there's some real potential for disaster. Not only do high-proof spirits deny the gelatin access to water for hydration, direct exposure to alcohol may denature the proteins altogether, rendering them useless.
Likewise, some plants contain protein-digesting enzymes that can destroy gelatin as well. These include fresh pineapple, papaya, kiwi, mango, and fresh ginger, so it pays to do a little bit of research before making any substitutions.
Issue #5: Time
The Scenario: You've got a recipe that works like a charm, but it doesn't always turn out the same from batch to batch. You've got the technique down pat, so what's going on?
Years ago, I noticed that my marshmallows occasionally turned out extra fluffy. I was at a loss to explain it, and stymied by the sheer number of variables in a commercial kitchen (from flavor to ambient temperature, et cetera), so, for a time, I just chalked it up to luck. Over the years, I eventually noticed that my best marshmallows were always the ones I prepped the night before, something I'd do in the busy season to get a jump on my morning chores. Check it out.
These pitcher-shaped marshmallows were made with identical ingredients, equipment, and cooking/cooling temperatures, but the one on the right started with gelatin I bloomed four hours in advance. Whoa.
On a certain level, we all understand that gelatin gets thicker with time. Jell-O is thin and watery when we put it in the fridge, gooey an hour later, then firm and jiggly an hour after that. What isn't so obvious is that those improvements to strength begin the moment gelatin is first bloomed. So, when I bloomed my gelatin the night before, my marshmallows benefited from its accumulated strength. It's a nifty trick, but not one I'd universally recommend.
The Danger: Some recipes use gelatin to aerate and stabilize a foundational element that's later re-whipped or folded with something else down the road (think: butter, cream, or meringue). Allowing bloomed gelatin to mature helps that base gain extra volume, but the added strength reduces its elasticity, making it difficult if not impossible to accommodate other ingredients later on. That's bad news for homemade marshmallow frosting, Bavarian cream, and even homemade Cool Whip—a recipe I'll tackle later this week.
Issue #6: Sugar
The Scenario: You can't believe how much sugar that recipe calls for! Surely it wouldn't hurt to dial things back.
I've said it before, and I'll say it again: Sweetness is sugar's least important role. Whether in marshmallows or in a simple fruit gelée, sugar competes with gelatin for water and alters the density of a solution, both of which can have a profound impact on gel formation.
The Danger: Lowering the amount of sugar in a recipe can speed gel formation, but it may also produce a softer set because, in the right amount, sugar can improve gelatin's rigidity. Sugar encourages gelatin to form shorter protein chains, creating tenderness in desserts, so cutting back can lead to seemingly gooier results.
If a recipe seems too sweet, the first and best course of action is to adjust the amount of salt. You can also tame sweetness by switching from plain to lightly toasted sugar, if you happen to have any on hand.
Suffice it to say, venturing off the beaten path with a gelatin-based dessert is a hit-or-miss proposition. Hopefully, understanding some of these conditions will shed a little light on past experiences and, more importantly, illuminate potential problems you may face down the road.
June 07, 2016
What can affect gelatin? ›
[3,4] The most important properties that charac- terize a gelatin for food applications are gel strength, viscosity, and both melting and gelling temperature. These properties are affected by various factors such as concentration, pH, gelling time, and salt content.What ingredients affect the setting of gelatin? ›
Normally the collagen proteins in gelatin form a tangled mesh that traps water and other ingredients in it, giving the gelatin its semisolid form when it cools. Proteases can cut up the proteins so that the gelatin cannot solidify.What to avoid when using gelatine? ›
Foods to Avoid When Mixing With Gelatin
Do not add fresh or frozen pineapple to gelatin or Jell-O. These fruits, along with raw figs, kiwi fruit, guava, and ginger root, contain an enzyme called bromelain which breaks down gelatin causing it to lose its thickening properties.
While making the jello, it is essential to dissolve the gelatin mixture in boiling water before adding the correct amount of cold water to the mix. Gelatin must dissolve entirely before adding cold water; otherwise, the jello will not set.Does some food ruin gelatin? ›
Key Takeaways: Fruits That Ruin Gelatin
Proteases are enzymes that break chemical bonds in proteins, such as collagen in gelatin. Pineapple, kiwi, papaya, mango, and guava are examples of fruits that cause a problem. Heat inactivates proteases, so cooking fruit before adding it to gelatin prevents any issue.
Back-of-the-box directions that call for boiling water give us the impression that gelatin is impervious to heat, but boiling simply represents its upper limit. Gelatin's strength rapidly declines above 212°F, or when it's held at that temperature for an extended period of time.Does temperature affect gelatin? ›
The extraction temperature had a significant effect on the gel strength of gelatin: the gel strength decreased as the gelatin extraction temperature increased. The gel strength of the gelatin extracted at a lower temperature (55 °C) was higher than the gelatins extracted at higher temperatures (65 °C and 75 °C).How does salt affect gelatin? ›
The effect of the addition of sodium chloride to gelatin solutions is shown from the Donnan relationship to increase the ionisation of the gelatin, the increase produced in acid solutions reaching a maximum at about 1/1000 molar salt concentration. This effect is attributed to the formation of complex ions.Does alcohol affect gelatin? ›
Alcohol can interfere with the setting properties of gelatin, so don't increase the proportion of alcohol to non-alcoholic liquid past this. You can, however, decrease the amount of alcohol.How does dairy affect gelatin? ›
Textural results showed that addition of all milk powders increased the hardness of gelatin gels at high gelatin concentration (5.0%). The fracturability of the gels was greatly influenced by pH. Addition of milk proteins and high gelatin concentration (5.0%) both caused loss of gel fracturability.
Can you grow bacteria on gelatin? ›
Bacteria are microorganisms that grow everywhere. We can collect and grow them in specially prepared dishes. The sugared gelatin is an excellent medium for supplying bacteria with nutrients and an environment in which we can see them grow.Why did my gelatine go lumpy? ›
If you use hot water, the exterior of the granules or sheets will swell too fast and that will prevent water from getting into the center. However, the bloomed gelatin should always be added to a warm base. Otherwise, the gelatin will start to set too quickly and get clumpy.Does humidity affect gelatin? ›
Gelatin is hygroscopic. It can absorb moistures from the air. High humidity may cause the gelatin to undergo extensive cross-linking during storage, which will affect it dissolution and swollen. This will further affect the drug release inside the capsule [7-9].Why does pineapple ruin gelatin? ›
Pineapple, kiwi and papaya all contain proteolytic enzymes, in other words enzymes capable of breaking down protein molecules. And gelatin, the substance that makes Jell-O gel, is a protein. Pineapple, kiwi and papaya all contain proteolytic enzymes, in other words enzymes capable of breaking down protein molecules.How does pineapple affect gelatin? ›
Since pineapple bromelain digests proteins, when the pineapple meets the gelatin, it begins to eat away at it. The long protein chains collapse, making everything watery again. Try adding papaya, kiwi fruit, or figs to gelatin.What fruit causes jelly not to set? ›
Fresh fruits such a pineapple, kiwi and papaya contain enzymes which break down these protein molecules, making them smaller, so they can't tangle up, which stops the jelly setting. This is similar to how the enzymes in your stomach break down food.Does hot water dissolve gelatin? ›
Gelatine powder needs heat to dissolve - if it's too hot it may not set and if it's not hot enough it can go lumpy.What happens when gelatin gets wet? ›
Gelatin is derived from animal collagen, which comes from the skin, bones, ligaments, and tendons. It is flavorless and odorless, and though brittle when dry, once wet it sets to become rubbery.Does freezing destroy gelatin? ›
Gelatin doesn't freeze well, in fact, it doesn't freeze at all! The structure of the gelatin, the stuff that makes it hold together, is destroyed when frozen and by the time you come to thaw it out, it becomes a liquidy mess rather than jelly-like. This is the same if you have added gelatin to any of your recipes.What temperature does gelatin degrade? ›
The degradation temperature of gelatin is around 340 °C. The weight of the sample decreases as the temperature of TGA increase (figure 3). Initially at low temperature T ( < 150 °C) compounds having low molecular weight like water decomposed first, temperature between (150 - 250 °C) additives decomposed.
What happens if you put gelatin in cold water? ›
"Gelatin is relatively insoluble in cold water but hydrates readily in warm water. When added to cold water gelatin granules swell into discrete swollen particles absorbing 5-10 times their weight in water.What happens to gelatin in the oven? ›
Tips for baking with gelatin
Things can get too hot to handle: Though heat is used to dissolve gelatin, there's a limit to just how hot. Once gelatin hits boiling temperatures (212°F), it can start to lose strength — meaning it won't enable marshmallows or molds to hold their shape well.
Sugar is the additive that created the strongest gelatin. The sugar gelatin had an average average of 118.6 grams needed to cut through it. The additive that makes the strongest gelatin is sugar.How does citric acid affect gelatin? ›
The addition of acid in the pectin-gelatin composition reduces the pH, the solubility of pectin and accelerates the formation of jelly. This is due to the fact that in the presence of citric acid reduced the degree of dissociation of galacturonic acid.Does vinegar prevent gelatin from setting? ›
Acids such as fruit juices or vinegar as well as whipping the gelatin will weaken the setting property of gelatin. Add solid ingredients when gelatin is partially set so they won't float. Use ice to replace part of the liquid to shorten setting time.Does vinegar affect gelatin? ›
The observation was made that while both vinegar and alcohol slowed the process of gelatinization, neither stopped it completely. Alcohol had the most effect in both trials. It was concluded that this was because of its affect on the overall pH of the gelatin which minimized its gel forming ability.Can you put vinegar in gelatin? ›
Pour the boiling water and vinegar mixture into the gelatin mixture. Stir it well until the gelatin dissolves. Pour the mixture into a flat-bottomed glass container and put it in the refrigerator for several hours, or until the mixture becomes firm.Does pH affect gelatin? ›
Measurement of the gelatin pH value is important to do, because the pH of gelatin solvent affects other properties such as viscosity and gel strength, and will affect gelatin application in the product. Gelatin with a neutral pH will be stable and its use will become wider .What causes gelatin to liquify? ›
Gelatin is a protein that is solid at room temperature. If the bacterium makes the enzyme gelatinase (which optimally is produced at 25º C, not 37º C), the gelatin is hydrolyzed and becomes a liquid.How does concentration affect gelatin? ›
Melting and gelling temperature values increased with increasing concentration for all gelatin strength and pH values in the range from 3 to 6. Both Tm and Tg increased with increasing gelatin concentrations. It was found that Tm and Tg are not affected by the applied frequencies.
How does gelatin affect ice cream? ›
Gelatins are the food ingredients obtained from collagen. It is tasteless and colorless. When added to Ice-creams, it acts as an emulsifier (an additive which is used to mix two liquids). It gives the Ice-cream its texture and keeps it fresh.What bacteria breaks gelatin? ›
cereus, B. subtilis, Clostridium perfringens and C. tetani ,are also positive for gelatin hydrolysis. The test can be used to differentiate genera of gelatinase-producing bacteria, such as Serratia and Proteus from other members of the family Enterobacteriaceae.Why does gelatin need boiling water? ›
Many people confuse "softening" with "dissolving". Softening gelatine in cold water or another cold liquid helps the granules swell, which is the first step in dissolving. To actually dissolve the granules, boiling liquid or heating the cold liquid in which the gelatine is softened is needed, plus some stirring.Can fungi grow on gelatin? ›
Most fungi will grow well on commercial agar plates such as Sabaroud Dextrose agar plates and many will grow on the homemade gelatin medium.What happens if you put too much gelatin to the mixture? ›
The simple ratio for gelatin powder to liquid
And if you use too much gelatin your end result will be rubbery jelly. Similarly, the longer gelatin sits in the fridge, the rubbery its texture.
Gelatin has a fairly low melting point and will become liquid if left in a warm environment.Is gelatin activated by heat? ›
Once you have bloomed your gelatin, heat up the liquid that you want to become a gel. You don't need to bring the liquid to a boil but instead, just need to heat it up, so that it is hot enough to dissolve the bloomed gelatin.What bacteria can break down gelatin? ›
Gelatinases are proteases secreted extracellularly by some bacteria which hydrolyze or digest gelatin. The production of gelatinases is used as a presumptive test for the identification of various organisms, including Staphylococcus sp., Enterobacteriaceae, and some gram-positive bacilli.Is gelatin affected by heat? ›
Gelatin, when subjected to prolonged heating at high temperatures, is denatured. Such heat‐denatured gelatin is altered in its solubility characteristics but is still subject to enzymatic hydrolysis.Is gelatin affected by pH? ›
The change in pH caused by decomposition has a significant effect on the emulsion gelatin. The increased solubility and general softening of the emulsion layer increases the risk of damage to the image and reduces the options available for treatment.
How does water affect gelatin? ›
"Gelatin is relatively insoluble in cold water but hydrates readily in warm water. When added to cold water gelatin granules swell into discrete swollen particles absorbing 5-10 times their weight in water.