Mojito Roulade or Jelly Roll Cake Recipe TutorialInfusing flavor into a liquid, such as heavy cream or whole milk, or sugar syrup, is a way of extracting the essence of a flavor from an ingredient, such as a vanilla bean, culinary lavender flowers, or orange zest. It is a simple procedure by first typically heating the flavoring agent with the liquid, just shy of a boil, and then setting the mixture aside to steep until the liquid is richly flavored, usually 30 minutes to an hour. Afterwards, before using in a recipe, the flavoring agent is sometimes strained from the liquid. 
SARAH SAYS: The more fat that the ingredient contains, such as heavy cream versus skim milk, the more it is capable of holding stronger flavor, but it also depends on the flavoring agent. For example, a cinnamon stick imparts a very strong flavor, and can do an excellent job at infusing flavor into apple cider, for example. Apple cider does not contain any fat.

This how to baking technique is used with the Mojito Roulade (Jelly Roll) Cake Recipe Tutorial
HOW TO TIPS: 

INSTRUCTIONS
1. Add the sugar and water to a small sauce pan and stir to dissolve.

2. Place pan on the stove and heat until the mixture comes to a simmer, and sugar is completely dissolved, about two minutes.
 

3. Remove pan from the heat and add the mint leaves.
Stir them into the syrup and let them steep for 30 minutes, so the oils from the peppermint leaves flavor the syrup.
 

4. After 30 minutes, pour the syrup through a strainer to remove the mint leaves.
 

5. Add the rum and lime juice to the syrup, and set it aside to cool.

 

STORAGE
Use immediately or refrigerate indefinitely in a covered container until needed.

VARIATIONS
This how to baking technique is used with the Classic Creme Brulee Recipe Tutorial
Espresso
Creme Brulee:
Crush 1/2 cup espresso beans into coarse pieces, add to the cream/milk, and heat to a simmer. Remove from the heat; infuse for 5 min. Strain and proceed.

Ginger Creme Brulee:
Cut a 3-inch piece of fresh ginger into very thin slices, add to the cream/milk, and heat to a simmer. Remove from the heat; infuse for 15 to 20 min. Strain, bring back to a simmer, and proceed.

This how to baking technique is used with the Master Ganache Recipe:
Earl Grey Ganache: Place 1 bag of Earl Grey tea in the cream and bring it to a boil. Cover and let it steep for 10 minutes. Remove the tea bag and squeeze over the cream. Rewarm the tea-infused cream and continue with the recipe.

Lavender Ganache: Place 1 to 2 tablespoons lavender flowers in the cream and bring it to a boil. Remove from the heat, cover, and let it steep for 10 minutes. Strain and rewarm the lavender-infused cream, then continue with the recipe.

Orange Ganache: Add 1 tablespoon finely grated orange zest to the cream and bring to a boil; strain into the chocolate. When the ganache is complete, add 1 tablespoon Grand Marnier.

This how to baking technique is used with the Basic Simple Sugar Syrup with Flavor Variations Recipe Tutorial:
Vanilla: Add half a vanilla bean to the mixture before bringing it to a boil. Remove bean after mixture has cooled and strain through a coffee filter, if necessary.

Orange /Lemon: Add the peel from half an orange to the mixture before bringing it to a boil; after it cools, strain through a coffee filter and add 2 tablespoons Grand Marnier and optionally, with 1 tablespoon finely minced orange peel. Substitute the orange with lemon peel and then use 1 tablespoon lemon juice instead of Grand Marnier.

Coffee: Replace the water with strong brewed coffee, or stir in 1 teaspoon instant espresso powder right after boiling – not before because the syrup will become bitter.

Herbs: Add a tablespoon of chopped herbs (or a few sprigs) such as rosemary or lavender before boiling. After syrup cools, strain through a coffee filter.

Juices: Replace part of the water with fruit juice.

Caramel: Put the sugar in a medium, heavy-bottomed pan with high sides and turn the heat on high. Melt the sugar, stirring with a wooden spoon, until it's a deep golden brown, about 7 minutes. Once golden, turn off the heat and add a cup of hot water. Watch out: It will boil up. Let the boiling subside and stir; return to low heat if any sugar solids remain. Cool.

Caramel-spice: Infuse the hot water for the caramel syrup with spices such as cinnamon or black peppercorns or even chiles. Remove or strain the spices.