Taro or yam however you call it, is a starchy root vegetable commonly use to make asian desserts such as Orh Nee. A kind of sweetened yam paste usually served in a bowl with some coconut milk and boiled gingko nuts. This root vegetable is especially popular in Taiwan. I was treated to some really nice taro desserts during my previous trip to Taipei. One particularly memorable dessert was a taro swiss roll from a well-known local bakery call Siang Shuai Cake. The roll cake was cottony soft and the taro paste within was smooth and fragrant. It was so good that I had two servings even after a very full meal. Since travelling is still not possible anytime soon, thus I decided to satisfy my craving by making the cake I miss dearly.
This recipe that I’m sharing is a simple light cotton sponge cake rolled in a lightly sweeten taro paste. The quantity for the paste is sufficient to fill the cake plus decorating over the top. Try piping the paste with a mont blanc piping tip, decorate with gingko nuts and edible dried flowers. Now you have a cake to impress. However the decorative part is a personal preference . No one is going to judge if you prefer to omit the decor. Add some coconut milk to the extra taro paste, and there you have a nice bowl of Orh Nee.
The taste of taro can be rather mild, therefore a lightly flavoured cake works better to allow the taro to shine. In this post, I’ll be sharing my simple method to make very smooth taro paste without using the food processor. In addition, I’m also sharing the steps to whipping meringue and methods to roll the cake. I hope these visual instructions can guide you better to success in making the cake. So let’s get baking shall we!
How to make smooth taro paste
Smooth texture is very important for a delicious taro swiss roll. In this section, I will show you how to achieve a very smooth taro paste without using the food processor.
You will need:
- A fine mesh sifter. This type.
- A bench scraper
- Prepared taro paste (refer to the recipe at the end of the post on how to prepare taro paste)
- Start by placing the sifter upside down on a plate. Dollop a small portion of the prepared taro paste on the sifter.
- Using a scraper, scrap the paste through the sifter. Repeat with remaining taro paste.
- The taro paste should now be all underneath the sifter. Scoop into a container, cover with clingwrap and refrigerate until ready to use.
Whipping techniques for egg whites
The key to achieve a soft airy sponge cake without the use of leavening agents such as baking powder, is a properly whipped meringue. This section shows you the steps to whipping meringue for the sponge cake.
You will need:
- Electric mixer
- Chilled egg whites
- Lemon juice (optional)
I find using chilled egg whites yields a finer meringue. In addition, a bit of lemon juice can help to prevent over whipping. However you should only add a small amount. Not more than 1 teaspoon of lemon juice for 3 egg whites. It is ok to omit the lemon juice though.
- Start by whipping the egg whites until foamy.
- Add 1/3 of the sugar and whip on medium high speed until no big bubbles.
- Now add another 1/3 of the sugar and continue whipping until soft peaks form.
- Add the remaining sugar and whip until firm peaks form. The meringue should look glossy.
- Add the egg yolk one at a time. Whip on low speed to emulsify before adding the second egg yolk. Mixture should look smooth with a sheen. Do not over mix.
- Sift in flour and gently fold to combine. Mix oil and milk together in a small bowl and add to the batter. Gently fold until just combine. Do not over mix. You don’t want to deflate too much of the air in the batter.
- Finally, pour mixture onto the middle of the prepared pan. Spread evenly with scraper.
How to assemble the roll cake
- Once the cake is cool, peel off the skin from the top of the cake. You can do this easily by gently rubbing the skin away. This is purely for aesthetic purpose. You can leave the skin on if you prefer.
- Overturn the cake on a clean sheet of parchment paper so the bottom is facing up. Chose a least pretty side and trim off about 1cm at an angle.
- Brush cake with syrup. Spread taro paste on the cake evenly leaving about 1cm space uncoated at the trimmed side. This is to allow a nice closure without having the taro paste oozing out at the end of the roll cake.
- Start by folding the cake from the opposite edge. Roll up to form a log with the help of the parchment paper.
- Use a long scraper or ruler to tighten the ends by pushing the base of the cake inwards.
- Refrigerate for at least 30 minutes to set the shape.
Cottony Soft Taro Swiss Roll
- 250 grams taro peel and slice
- 30 grams canola oil
- 60 grams heavy cream
- 50 grams granulated sugar
- 1 tsp dark rum optional
- 3 egg whites preferably cold
- 2 egg yolks
- 45 grams granulated sugar
- 40 grams cake flour
- 20 grams canola oil
- 2 tsp whole milk
- 1 tsp lemon juice optional
- 1 tsp sugar
- 2 tsp water
- 1 tsp dark rum optional
- a few pieces of boiled gingko nuts
- handful of dried edible flowes
- small amount of edible gold flakes
- 2 tsp snow sugar for dusting
- Steam the taro slices over high heat for about 10 to 15 minutes. Test doneness with a fork. Taro should be very soft. Mashed with a fork while still hot.
- Place the mashed taro onto a nonstick frying pan together with the rest of the ingredients for the taro paste.
- Over medium heat, stir constantly with a spatula until sugar melted and all the ingredients combined well. The paste should look glossy and not too dry. Remove from heat.
- Place a sifter upside down on a plate. Dollop a portion of the prepared taro paste on the sifter. Using a scraper, scrap the paste through the sifter. Repeat with remaining taro paste. Scoop into a container, cover with clingwrap and refrigerate until ready to use.
- Preheat oven to 180C. Line a 23cm by 23cm square shallow baking pan with parchment paper. Set aside.
- Using an electric mixer with the whisk attachment, whip cold egg whites and lemon juice (if using) until foamy. Add 1/3 of the sugar and continue whipping at medium high speed until no big bubbles. Now add another 1/3 of the sugar and continue whipping until soft peaks form. Add the remaining sugar and whip until firm peaks form but still glossy.
- Add in 1 egg yolk and beat on low speed to emulsify. Repeat with the 2nd egg yolk. Mixture should look smooth with a sheen. Do not over mix.
- Sift in flour and gently fold to combine. Mix oil and milk together in a small bowl. Add to the batter. Gently fold until just combine. Do not over mix.
- Pour mixture onto the middle of the prepared baking pan. Spread evenly to all 4 corners with a scraper.
- Drop the pan from a height once to break up big air bubbles. Bake at 180C for 14 to 16 minutes.
- Cover the cake with a piece of clingwrap. Invert the cake on a wire rack, peel off the baking paper and cover it back. Invert the cake back with the clingwrap side facing up. Leave to cool completely.
- Combine sugar, water and rum (if using) in a small saucepan. Cook until sugar dissolve. Set aside.
Assemble the Cake
- Remove the clingwrap from the cake. Peel off the skin from the top of the cake by gently rubbing it away. It should come off quite easily. You may skip this step if you prefer to retain the skin.
- Overturn the cake on a clean sheet of parchment paper so the bottom is facing up. Chose a least pretty side and trim off about 1cm at an angle. Brush cake with all the syrup. This is to keep the cake moist.
- Remove taro paste from the refrigerator. Add 2/3 of the paste onto the cake. Spread evenly with an offset spatula leaving about 1cm uncoated at the trimmed side. From the opposite edge, roll up the cake to form a log with the help of the parchment paper. Use a long scraper or ruler to tighten the roll by pushing the base of the roll inwards. Refrigerate for at least 30 minutes.
- Take out the cake from refrigerator and remove the parchment paper. Trim off both corners of the roll. Place on plate or cake board.
- Fill a piping bag fitted with mont blanc piping tip (I use Wilton tip 234) with the remaining taro paste. Starting from one end of the roll, pipe on the top of the roll in zig zag motion. Decorate with boiled gingko nuts, edible dried flowers, edible gold flakes and dusting of icing sugar if you like.
Did you make this recipe? Tag @vanillynbakery on Instagram