Meringue Mushrooms for Yule Log

Quick Summary: Meringue mushrooms, or Yule log mushrooms, are crisp Swiss meringue cookies piped into caps and stems, baked low and slow, then joined with melted chocolate and dusted with cocoa. Made from just four ingredients, they are a classic decoration for a Buche de Noel and woodland cakes.

What are meringue mushrooms?

Meringue mushrooms are bite-sized cookies shaped to mimic real forest mushrooms. Separate caps and stems are piped from meringue, baked until dry, then attached with a dab of chocolate and dusted with cocoa so they look freshly picked. Their crisp shell and hollow center melt away the moment you bite in.

This French pastry classic traditionally crowns a Bûche de Noël, evoking the mossy log it is styled after. The mushrooms also suit woodland desserts such as a Tree Stump Cake, and they double as an edible gift or a fun addition to a Christmas cookie box.

The meringue mushroom recipe is perfect for both dry and rainy days. Maida Heatter, the author of numerous dessert cookbooks, lives in a humid climate. She "made these innumerable times in Miami Beach, where it is almost always humid, they [meringue mushrooms] are always perfect."

Why you'll love this recipe

• Just four ingredients and basic piping skills are all you need.
• They keep for weeks, so you can make them well ahead of the holidays.
• The low, slow bake gives them a crunchy texture and a clean white color.
• They turn a Buche de Noel or woodland cake into a showpiece.
• They double as edible gifts and a fun addition to a Christmas cookie box.
• Kids love helping pipe the caps and stems.

Ingredients

For ingredients and detailed instructions, refer to the recipe card below.

• Egg whites: large egg whites at room temperature.
• Icing sugar: the same as powdered and confectioners' sugar.
• Unsweetened cocoa powder
• Dark chocolate: melted dark chocolate (read how to melt chocolate) or replace it with milk, white chocolate, or chocolate chips.

Note: Dark chocolate gives meringue mushrooms a more realistic look under the cap. You can also use royal icing or buttercream instead of melted chocolate to "glue" meringue caps and stems.

Equipment

You need only a few basic tools to make these meringue mushrooms:

• Stand mixer or hand mixer
• Heatproof bowl
• Piping bags
• Round piping tip
• Baking sheet
• Parchment paper
• Fine-mesh sieve

How to make meringue mushrooms step-by-step

Preheat the oven to 210°F (100°C). Line a baking sheet with parchment paper. 

Step 1. To make Swiss meringue, place egg whites in the clean bowl of a stand mixer or a large metal bowl.

Step 2. Add powdered (icing) sugar and whip egg whites with a hand whisk a few times. Place the bowl over a bain-marie (water bath) and beat the egg whites with a whisk until foamy.

Step 3. When the meringue mixture is hot, remove the bowl from the heat and beat it with a stand or electric mixer until it cools completely. The meringue will be glossy with stiff peaks. Use it right away.

Step 4. Transfer meringue to a large piping bag with a round piping tip of ½" (12 mm). Pipe 4 meringue dots in the corners of the prepared baking sheet and place parchment paper on top. It will keep the paper in place during piping and baking.

For the mushroom caps, hold the piping bag upright on the baking sheet and squeeze smoothly. Push the meringue into a plain round shape (photo 1).

Once you have the perfect shape, stop squeezing and slowly remove the bag to the side to avoid creating a peak on top. If needed, use a wet fingertip to flatten the spike of the meringue dome.

Step 5. Hold the pastry bag upright on the baking sheet to pipe the meringue stems. Start piping gently, forming a stem's base, then lift the bag while squeezing. To make the pointed end, pull up the bag (photo 2). Place caps and stems 1 inch (2.5 cm) apart.

Pro tip: The size of mushroom caps and the height of stems may vary: while the caps may average 1 to 2 inch (2.5 cm to 5 cm) rounds and about 1 inch (2.5 cm) high, the stems may get about 1 inch (2.5 cm) tall.

Step 6. Sprinkle mushroom caps with cocoa powder.

Step 7. Bake caps and stems for 1 hour. Once the meringues are ready, let them cool, then detach them from the parchment paper.

Step 8. To assemble meringue mushrooms, carefully select and arrange the caps and stems to achieve the most visually appealing size and shape combinations. Melt chocolate according to any of the ways described in the chocolate mousse recipe.

Then use one of the provided assembly methods.

• Make a small hole on the bottom of each cap with the tip of a small paring knife. Fill the hole and the top of the stems with a little melted dark chocolate. Insert the stems into the hole under the caps. Place the mushrooms upside down and refrigerate to set the chocolate.

• Slightly trim the tops of the mushroom stems evenly using a serrated knife. Using a small offset spatula, coat the bottom of the cap with melted chocolate (photo 3). Dip the tip of a mushroom stem into the chocolate and twist it gently to attach the cap and stem together (photo 4). Place the assembled mushroom upside down on a wire rack lined with parchment and allow the chocolate to set.

Pro tip: Don't worry about slightly crooked stems: they will appear perfect when flipped over. However, adjust any completely fallen stems.

Step 9. Sprinkle a little cocoa powder on the upright meringue mushrooms to give them a freshly emerged look from a patch of soft earth.

Expert tips

1. Make sure egg whites are at room temperature.
2. Pipe different sizes of mushroom caps and stems.
3. Make a few extra stems, since some may fall during baking.
4. Once meringue caps and stems are baked, keep the oven door slightly ajar to allow the meringues to cool, although it is optional.
5. Keep the baked caps and stems uncovered in an airtight container for a few days before assembling the mushrooms.
6. Store ready-made meringue airtight in an airtight container for a few weeks.
7. While presenting a Bûche de Noël, decorate an airtight platter with meringue mushrooms, fixing them with melted chocolate. This prevents them from breaking if they accidentally fall while serving the log to a holiday table.

Recipe variations

• Replace cocoa powder with sifted freeze-dried strawberry powder on meringue mushroom caps.
• Use a little red food coloring in the meringue to make red toadstool tops, then pipe small white dots for the classic spotted look.
• Experiment with the shape and size of the meringue mushrooms. According to Maida Heatter, "Smaller or larger mushrooms are equally attractive."
• To make more realistic mushrooms, rub cocoa powder into the baked meringues and buff their caps and stems.

Storing & freezing

Store the cooled meringue mushrooms in an airtight container, preferably a tin box, at room temperature for up to two weeks.

To freeze meringue mushrooms, place them on parchment and freeze. After one hour, transfer meringues to an airtight container and keep them in the freezer for several weeks.

To thaw, bring to room temperature for about an hour. 

Recipe FAQ

What are the mushrooms on a Buche de Noel made of?
Meringue mushrooms are the classic decoration for a Buche de Noel or Christmas Yule log cake. They are made from Swiss meringue, piped into caps and stems, baked until crisp, then dusted with cocoa powder. Prepare them ahead of time to adorn the Christmas dessert.

What is the best oven temperature for meringue mushrooms?
Bake meringue mushrooms low and slow at 210°F (100°C). A low temperature dries them out without browning, keeping them white and crunchy.

Why did my meringue mushrooms crack?
Meringue mushrooms crack due to high oven temperature or sudden temperature changes. Prevent this by baking them at a low temperature and letting them cool in the switched-off oven with the door slightly ajar.

How long do meringue mushrooms last?
Kept uncovered or in an airtight container in a cool, dry spot, assembled meringue mushrooms stay crunchy for a few weeks. Humidity is their enemy, so avoid storing them anywhere damp.

Can you store meringue mushrooms in the fridge?
Meringue mushrooms are sensitive to humidity. To keep their crunchy texture, it is not recommended to keep them in the fridge.

How many calories are in meringue mushrooms?
One meringue mushroom has about 61 calories.

Love Christmas cookies? Try these next!

• Mini Gingerbread Men Cookies
• Chocolate Banana Pecan Cookies
• Cranberry Oatmeal Cookies
• Bredele Cookies
• Christmas Cookie Ornaments
• Or browse all the cookie recipes

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Recipe card

The nutritional information has been calculated using an online recipe nutrition calculator such as Verywellfit.com and is intended for informational purposes only. These figures should be used as a general guideline and not be construed as a guarantee.

The recipe was originally published on May 05, 2018. It has been revised to include improved content and photos.