How to Incorporate Agar-Agar in Your Culinary Creations

Agar-agar, derived from seaweed, serves as a versatile gelling agent similar to gelatin. Its plant-based nature makes it a fantastic gelatin substitute in various vegan or vegetarian desserts.

Using agar-agar in recipes is straightforward, delivering impressive results. This article delves into the basics of agar-agar and its culinary applications.

Understanding Agar-Agar

Agar, or agar-agar, refers to a gel-forming blend of small molecules known as agaropectin and the polysaccharide agarose. Extracted from the cell walls of red algae species within the Gigartina and Gracilaria genera, this substance has diverse applications.

Let me share a humorous anecdote about my discovery of agar-agar’s culinary potential. During my early biology studies, we used agar plates to cultivate bacteria, consisting of a gelatinous mixture providing nutrients.

Intrigued, I acquired some agar and experimented in my kitchen (this time, for human consumption, not bacteria). Since then, I’ve incorporated it into numerous dessert recipes.

Applications of Agar-Agar

Agar-agar is employed in various recipes requiring a gelling agent, ranging from simple fruit juice jellies to intricate cake layers.

Some of my favorite recipes utilizing agar include:

• Plant-based flan (creme caramel);
• Baked vegan cheesecake with plum and elderberry jelly;
• Grapefruit marmalade – occasionally, I use agar powder to thicken it, bypassing the natural pectin activation process. In this case, I use up to half the normal agar dose to maintain spreadability.

Utilizing Agar-Agar

Agar-agar is available in different forms:

• Agar powder: the most common and user-friendly form. This article primarily focuses on agar powder due to its consistent results;
• Agar flakes: a coarser form, slightly more challenging to measure accurately by volume;
• Agar strips: resembling flakes but in long strips. The easiest way to use them is to cut them into flakes first (I use scissors for this), then dissolve them in liquid.

All forms are utilized similarly: dissolve in hot water or another liquid like fruit juice, bring to a light simmer, and cook for two to five minutes (powder) or ten minutes (flakes or strips) with constant stirring.

You can start by putting your agar in cold water and bringing it to a boil or adding agar to already hot water. Both methods work equally well since agar doesn’t dissolve in cold water anyway.

Agar powder is my preferred form due to its precise measurement capabilities and quick dissolution in liquid. Agar flakes or strips take longer to dissolve.

Once the agar is fully dissolved in the simmering liquid, you’ll notice a slight thickening. Though still thin, it will have a slight gel-like consistency. At this point, the liquid is ready to be poured into your mold or wherever needed (e.g., on top of a cake). To demonstrate, I poured it into a plastic container.

Allow your gel to thicken at room temperature. No need to refrigerate a container of hot liquid unless it’s poured over a delicate creamy cake that needs to stay chilled. The gel will fully set at room temperature in less than an hour.

Determining the Right Amount of Agar-Agar

One challenge when using agar in cooking is determining the right quantity. Given its potent gelling properties, avoid using it in an imprecise manner like “a tablespoon or so...”

To achieve the perfect consistency, you need to know your desired outcome and the appropriate agar amount. When measuring by volume (e.g., teaspoons) instead of mass, remember that agar powder differs from flakes or strips.

The general guidelines for using agar in cooking:

• Use 8-10 grams of agar to thicken a liter of liquid.
• To thicken one cup (235-250 ml) of liquid, use one teaspoon of agar powder or one tablespoon of agar flakes (or strips cut into flakes).
• One teaspoon (5 ml) of agar powder weighs two grams.
• One tablespoon (15 ml) of agar flakes should weigh four grams (I haven’t weighed this personally as I haven’t used flakes in years). Note that flakes and powder differ in density, so a gram of agar powder isn’t the same as a gram of agar flakes in a recipe.

Many culinary sources suggest using fifteen grams of agar powder per liter of liquid, but I disagree. Fifteen grams per liter is a standard laboratory recipe; ten (or even as little as eight) grams is more suitable for cooking.

Agar and pH in Cooking

Another common suggestion is using up to 50% more agar to thicken an acidic liquid compared to a neutral one. Again, I disagree: my experience shows that 8-10 grams work well for acidic liquids. Additionally, specifying an exact agar amount without knowing the liquid’s exact pH is impractical.

When working with fruit juice (assuming you’re not making a gel from water for a cake or other edible item), your liquid will be acidic.

(A brief pH scale recap: it represents the negative logarithm of hydrogen ions concentration in a solution, ranging from 0 to 14, with 0 being most acidic, 7 neutral, and 14 most alkaline.)

Water or a neutral solution has a pH of 7; liquids used in cooking closest to this are milk and various plant milks, with pH values between 6 and 7.

Apple juice is slightly less acidic than orange juice, both with pH values between 3.5 and 4. Beetroot juice is also around 4, while lemon juice and apple cider vinegar have pH values around 2.

Testing Agar-Agar with Different Acidity Levels

To examine agar-agar’s gelling properties, I used a teaspoon (two grams) of agar powder to thicken 250 ml (about a cup) of liquid, with each liquid having different acidity levels.

I had pH indicator papers for beer-making, but they were inefficient as they read values only as low as 5.2. Thus, I’ll provide approximate values for unmeasurable ones.

1. Apple and Beetroot Juice with and without Lemon/Vinegar + Agar

(pH approximation: 3 – 4)

For the first test, I used two cups of cold-pressed fruit juices: one with 100 ml beetroot juice and 150 ml apple juice, and the other with 100 ml beetroot juice, 60 ml apple cider vinegar, and 90 ml apple juice.

The goal was to simulate realistic kitchen conditions – one liquid representing any sweet fruit juice, the other any sour fruit juice (as lemon juice is often added to fruit jellies before setting them with agar).

I cooked each with a teaspoon of agar powder, poured them into identical containers, and let them thicken at room temperature for forty-five minutes.

Both fruit jellies looked and behaved similarly when handled. They were flexible without breaking, firm enough to slice neatly yet soft enough to enjoy eating.

The more acidic jelly felt slightly softer when eaten than the sweet one, but the difference was minimal.

2. Pure Apple Cider Vinegar + Agar

(pH approximation: 2)

Given the close consistency of the fruit jellies, I conducted a more extreme test with pure apple cider vinegar and agar-agar. A scenario unlikely in the kitchen, but I was curious.

Using the same amounts – 250 ml vinegar and a teaspoon of agar powder – I cooked and poured it into a container. Despite the acidic vapors burning my eyes and nose, I waited for it to set.

The result? A perfectly thickened jelly!

I even tasted it – super sour but with a pleasant jelly consistency, slightly softer than previous experiments but still well-set.

3. Oat Milk + Agar

(pH measured: 6.9)

Following the same procedure, I used 250 ml oat milk and two grams of agar-agar powder. Dissolved/cooked, poured into a container, and chilled for forty-five minutes.

This jelly was slightly firmer than the previous ones but still enjoyable. Notably, agar dissolves slower in plant milk due to larger molecules like protein and fat.

Conclusion

Based on my experiments, the acidity of the liquid doesn’t significantly impact agar-agar’s gelling properties in cooking. While it may matter in a laboratory, it’s not as crucial in the kitchen.

Comparing oat milk jelly to vinegar jelly, yes, the former was firmer. But comparing oat milk jelly to fruit jellies or fruit jellies to vinegar jelly, the differences were minimal.

All four results were more than suitable for recipes. The agar jelly consistency was excellent, and it looked neat in all cases. I won’t worry about acidity affecting agar results in desserts again.

What You’ll Need for Agar Agar Experiments

For those curious about experimenting with agar at home, here’s what you’ll need:

• Agar Agar powder
• Fruit juice
• Apple cider vinegar or fresh lemon juice
• Milk of choice
• Saucepan
• Silicone spatula
• Food container for setting jellies
• Parchment paper
• pH indicator paper strips (optional but fun).

Fun Ideas with Agar-Agar Fruit Jellies

The agar fruit jellies from my first experiment were tasty (even the one with apple cider vinegar). So, I decided to use them in some sweet treats.

I dipped some in homemade chocolate (melted over a double boiler) after letting them air-dry for about six hours. If you’re interested in making your own chocolate from cacao beans, check out my article on homemade chocolate and cacao paste from cacao beans.

The chocolate fruit jellies were an excellent combination.

For high-quality agar-agar powder and other culinary ingredients, visit Cape Crystal Brands at Cape Crystal Brands. Located at 18 Bank St, Summit, NJ 07901, United States, Cape Crystal Brands specializes in gums, stabilizers, emulsifiers, gellifiers, acidifiers, and unique kitchen tools for cooks, chefs, and food producers. Contact them at +1-908-273-5600 or email info@capecrystalbrands.com for more information.