No Ordinary Dumpling: Jelly

No Ordinary Dumpling: Jelly

Welcome back to our No Ordinary Dumpling series, where our chef Brian Yong details the R&D process of how we here at XCJ developed our current recipe for our signature xiao long bao (小笼包), or XLB. He will be analyzing the three fundamental components of a soup dumpling: the dough, the filling, and the jelly (or the soup). In these posts, he’ll share both the highlights — and the struggles — of his development to create a dumpling that we are proud of, as well as a scaled-down, at-home-friendly recipe for anyone interested in making a version of our XLB.

Overview

I saved the jelly — sometimes also called the aspic — of the soup dumpling as the last installment of this series because it is arguably the most important part of the XLB composition. The perfect jelly is a fickle friend: it needs to be flavorful enough to add dimension to the eating experience, but not overly so that it overshadows the filling; the jelly should be rich on the tongue and add some heft, but not feel oily or too thick.

When done the traditional way, the jelly is a naturally gelatin-rich broth made from cooking down bones and larger cuts of meat (usually pork). For example, the aspic for sheng jian bao is usually made with pork skin. The collagen protein found in these cuts turns into gelatin once it cooks down, which has a useful property of being solid at cold temperatures (under 60°F) but liquid at warm and hot temperatures (above 104°F). This way, the jelly can be easily chopped into little pieces and incorporated into the filling mix, stuffed into the wrapper, then heated to fill an XLB pouch with soup right before eating.

However, making jelly the classic way adds a lot of variability into the final product. Because the amount of collagen (and thus, gelatin) of the bones and meat fluctuate widely per batch, some jelly may be softer or stiffer than others. To ensure all of our customers would be receiving the same jelly experience, I worked backwards using a set amount of gelatin to achieve a final desired consistency that could be replicated easily. The main variables I considered in this testing process were:

Viscosity

The viscosity of the final soup is determined by the percentage of gelatin in its base. As I had already established making the jelly by boiling bones and meat could not work at scale, I was left with two puzzle pieces. The first was developing a base stock (unseasoned) and seasoning it appropriately (turning it into a broth). The second was thickening it precisely with unflavored gelatin. 

For the stock, I decided to utilize a condensed chicken base. This is a very concentrated version of chicken stock that has had its liquid removed, which then allows me to control the amount of liquid added back to melt it again (and thus, its final flavor and salinity). Finally, this was both straightforward enough to be scaled across different kitchen teams and produced reliable results. If you’re thinking “chicken base?” you’re not alone — I also was hesitant to have a chicken jelly for a pork XLB, but interestingly enough pairing the pork base with the pork filling tasted a little too heavy and not particularly refreshing — especially if a customer eats multiple XLBs in one sitting.

Now, it was time to test gelatin percentages. I used a classic unflavored powdered gelatin, which is available in most grocery stores and is extracted from beef bones. Just like with the flour used in our dough, it’s also important to use the same brand of gelatin from batch to batch in order to keep the bloom value — or the variations in a gelatin’s gelling or melting points — the same. I like to use Knox brand gelatin. 

I ended up with a ratio of 4.4% gelatin to water for my jelly base. Similar to the idea of “minimum effective dose” in filling flavorings, this was the least amount of gelatin possible that would still set appropriately when chilled and pass through the meat grinder easily. It’s especially important that the jelly can be ground using the fine die, because it leaves smaller voids within the filling once the jelly melts back into liquid form in the heating process. (With a larger die, not only does the jelly leave bigger holes in the filling, it also makes the chilled version of filling bulkier, which risks overstretching the wrapper.)

Melting Temperature

Our pork XLBs are made with freshly ground pork, which needs to be cooked to 145°F in order to be safely consumed. This means that the jelly must also be liquid at this temperature, which is not a difficult ask for gelatin (which melts at 104°F). However, gelatin is extracted from animal bones and is not suitable for vegetarians and vegans, which is why vegetarian soup dumplings have such a hard time mimicking its meat-filled counterparts.

As we look to launch a vegetarian XLB, I had begun a long series of tests for what would be substitutable for a vegetarian or vegan gelatin. If you do a quick search online, you’ll likely see a lot of results for agar agar, a particular type of gelling agent derived from seaweed. However, the issue with agar — and many of its friends, like the carrageenans — is that the melting point is far too high, even in very low concentrations. Agar agar doesn’t melt until 185°F — that would be a scalding hot XLB to eat! After a long process of elimination, I am now testing out a blend of guar gum, xanthan gum, and locust bean gum to see if it can emulate that gelatin-esque mouthfeel and melting properties, so stay tuned for more updates soon from the kitchen.

Ratio to Meat

To determine the proper balance of jelly and filling, the two must be tested and tasted together — ratios can’t be made separately. While more jelly sounds like a good thing — after all, there’s nothing more disappointing than an XLB that doesn’t have any soup — too much jelly throws off the overall composition of the dumpling and can compromise the structure of the wrapper. 

I started with a 0.25 ratio of jelly to meat, and slowly worked my way up/down to our final ratio: 0.75 to 1, jelly to meat. That means for every ounce of filling, we use 0.75 ounces of gelled aspic. This gave the overall XLB plenty of soup to last a full 3-4 bites, but not so much soup that it would overpower the other flavors and textures.  

Flavoring Details

As I mentioned earlier, the main flavor of our jelly comes from a chicken stock concentrate. I also add splashes of shaoxing rice cooking wine (called 绍兴酒) to the chicken base to enhance the overall aromatics of our jelly. This is a rice wine originating from Shaoxing in the Zhejiang province. It is one of the oldest types of rice wine in China, and has both drinking versions and cooking versions (the latter has a higher salinity). While recipes often mention shaoxing as “substitutable” with a dry sherry, shaoxing has a very distinct aroma, sweetness, and a unique fermented rice fragrance that simply cannot be replaced.

It’s worth noting that aspic doesn’t need to be seasoned as heavily as a regular broth may be. Because it is mixed together with the filling, it extracts some of the flavors of the filling as it melts into soup form. The desired result is a soup that is seasoned enough to accentuate the ingredients of filling and aspic, but not so salty it prevents you from wanting several more sips.

Jelly Recipe

With the end of our No Ordinary Dumpling series, here is the final jelly recipe needed to make our xiao long bao at home. We use this for all of our XLBs at the moment, and are experimenting with a vegetarian version as well. Look out for that soon!

Gelatin                                                    25g
Shaoxing Wine                                        14g
220°F Chicken Broth                                300g
Room Temperature Chicken Broth           250g 

1) Bring 300g of chicken stock to simmer

2) Bloom 3 packets (25g) of gelatin in 250g of room temperature chicken broth in bowl

3) Pour hot chicken broth into bowl, and whisk until gelatin has melted. Pour contents into baking pan and chill until set (90 minutes or more in freezer, up to overnight in fridge)