Deep Frying Tofu

Black Pepper Tofu is one of Chris’ favorite dishes from Plenty by Ottolenghi. The book says it’s Chinese but it features Kecap Manis a Indonesian caramel sweet soy sauce which to my knowledge is never used in traditional Chinese cooking.  In short, deep fried tofu is drench in a sauce of kecap manis, Chinese light and dark soy sauces with plenty of sauteed shallots, ginger, garlic, red chillies and black pepper.

This recipe is almost perfect as a make-ahead dinner party dish because the flavors of the aromatics and the sauce mingle and develop when kept overnight in a refrigerator. The problem is that the deep fried tofu can’t hold its crispiness in the sauce for more than 10 minutes. I’m not expecting the crunch to hold up in the sauce overnight but if the tofu can remain crispy for an hour or two, then the sauce can be cooked the night before and the tofu fried just before the party.

A quick google search turned up this excellent post How To Cook Crispy Tofu Worth Eating from seriouseats.com. Tips from the post:

1) Start with non-siken firm tofu – I’m already doing that.

2) Dry the tofu before frying – The post recommends slicing the tofu then pour hot salted water over the slices and dry between pieces of paper towels. Previously, I just slice the tofu, dry with paper towels once and deep fry them immediately after dusting with corn flour. I followed the blog advice this time –  blanched the tofu and dry. I had to change the paper towels (double layered) 3 times before they were satisfactorily dry (paper towel remains dry for 1 minute).

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3) Coat with a batter of corn flour and vodka – The seriouseats.com post conducted a series of experiments with Korean Fried Chicken and concluded that coasting tofu with a batter of cornstarch and vodka results in a superior crust compared to a mere dusting or corn flour (or rice flour, potato flour and combination). The finding that cornstarch is the best starch for crispy deep fried food is confirmed by a issue of Cook’s Illustrated so I did not attempt to reconfirm this result. Instead, the focal point of my test was to find out if a corn starch-vodka batter is indeed superior to a water-corn starch batter and a seltzer-corn starch batter.

Method

I split the 1 block of tofu into 4 sets:

  • Dry corn starch dusting (Control)
  • Batter of water and corn starch (1 tbsp liquid + 1 tbsp corn starch)
  • Batter of seltzer water and corn starch (1 tbsp liquid + 1 tbsp corn starch)
  • Batter of vodka and corn starch ( 1 tbsp liquid + 1 tbsp corn starch)

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I heated the peanut oil to 350 °F (tested with a instant read thermometer), and lowered each batch of tofu into the oil for 4 minutes, flipping once at 2 minutes. The temperature of the oil was tested and adjusted between the batches.

Yep, there was less tofu in the Control batch because I took some out to boil for Miss Clarey. On hindsight I should take taken a cube from each batch so that the amount of tofu deep fried each time would remain constant.

The tofu were then mixed with the sauce in 4 separate dishes.

Result

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I wanted to test if the tofu would remain crisp after 1 hour but it was 8 pm by the time I was done so we just gave it a 10 minutes rest.

It was obvious that all 3 of the battered tofu were crispy and crunchier than the Control batch (dry dusting). Even though I dried the tofu more thoroughly then usual, there didn’t seem to be any improvement compared to my previous attempt. In fact all the tofu coated in batter (liquid + corn starch) did better, which caused me to revisit the wisdom of drying the tofu thoroughly. The blog post I referred to didn’t explain the rationale and from various other recipes, it seems like the drying of tofu is mainly to allow the tofu to absorb more marinate. Since there is no marinate in this recipe, maybe drying the tofu and then just applying a dry dusting of cornstarch was actually counter productive since it seems that liquid+cornstarch resulted in better texture.

Among the 3 test batches, the vodka-cornstarch batter coating resulted in the crispiest crust which remain crispy at the end of dinner (about 30 minutes after mixing with the sauce). The other two were less crispy and got progressively so with time.

Conclusion

So it’s definitely a vodka-corn starch batter for deep frying tofu next time and even if I’m out of vodka, water and cornstarch is better than just a dusting of corn starch.

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Velvet Chicken

I’ve never been a fan of chicken breast. Yes yes it’s leaner than dark meat but it’s also usually dry and tough. Until I tried it in Golden House, my favorite Chinese restaurant in San Jose. At first I was disappointed that my order of chicken with snow peas and chestnut came with VERY WHITE bite-sized pieces of chicken breast and wanted to kick myself for not checking before ordering but it turned out that my negligence introduced me to the world of ‘velveting meat”.

I couldn’t stop exclaiming at how tender the meat was and how the lack of any browning of the meat was perfect because of the delicate sauce.

Me: I don’t want to know what freaky thing they did to the chicken to make it so good.

Chris: Freaky thing? I think it’s velveting.

Me: Yeah velvet is a kind of fabric. You just made it up.

Chris: It’s a cooking technique, I read about it in the Chinese Stir-fry book I bought for you.

That shut me up since I didn’t want to admit that I’ve never read that recipe book. Indeed, it turned out that according to Stir-frying to the Sky’s Edge by Grace Young,

“The Chinese revere foods prepared with the silky, smooth texture known by the Cantonese as waat. No other cooking technique produces such light, delicate, tender succulence, hence the culinary term “velveting” in English. This style of stir-fying, popular with chefs, is most typically accomplished by briefly marinating bite sized pieces of beef, pork, chicken, fish scrimp or scallops in a standard combination of egg white, cornstarch, and a little water or rice wine. The marinated morsels are then blanched in oil or water and thoroughly drained in a colander before being stir-fried.”

Hmm, that doesn’t sound difficult at all so I decided to try the Velvet Chicken with Asparagus recipe in the book. The introduction to the recipe says,

“This is one of the most refined stir-fries. The flavors are deliberately mild and subtle so that the textures of the main ingredients can be better appreciated: the chicken breast is silky smooth, with extraordinary succulence, and the asparagus is crisp-tender.”

Ok, how can I NOT try that? This sounds eerily similar to the chicken I was raving about in Golden House.

Trial 1: Method

I followed instructions faithfully, sliced 1 lb of chicken breast into 1/4 inch thick bite-sized slices and marinated them in 2 tbsp of egg white, 1 tbsp of cornstarch, 2 tsp of rice wine and 3/4 tsp of salt for 30 minutes in the refrigerator. 1 tbsp of cooking oil was added to 1 quart of boiling water, boiling water reduced to a simmer before the chicken was gently poached. The recipe says to “cook for 1 minute, until the chicken is opaque but not cooked through”. For my 1/4 inch thick slices, the surface of the chicken slices was still pretty transparent after 1 minute and took 2 minutes before they turned opaque.

Chicken poaching for velveting

After the chicken and asparagus were cooked separately, they were combined with the aromatics and a delicate sauce of chicken broth and rice wine was swirled into the dish at the end.

Trial 1: Results

Not very impressive. The asparagus was indeed crisp tender, the sauce was delicate but the most important part of the dish, the texture of the chicken was pretty far from what I had in Golden House. The exterior of the chicken was softer than chicken breast stir-fried without any velveting but the interior was pretty dry and with 1/4 inch thick pieces that meant that the majority of the chicken was dry. It pretty much reminded me of regular chicken breast dishes I have had in other Chinese restaurant which led me to suspect that velveting is actually commonly practiced in Chinese restaurants but not all restaurants do it well. In any case the technique is obviously not as easy as I thought.

Trial 2: Method

After studying several recipes online which utilized the water velveting technique, I found the velveting marinate to be essentially the same, either 2 tbsp or 1 egg white and 1 tbsp of corn starch to 1 lb of chicken breast, with a little rice wine or water to thin the mixture and 1 tbsp of oil to coat the chicken. However, none of the recipes agreed on the thickness of the chicken pieces, one called for 3/4 to 1 inch cubes, while some others just left it as bite-sized slices. The timings for the poaching were also often not precisely described. How was I supposed to know when the chicken is “90% cooked”? Therefore I gathered that to match Golden House’s soft and succulent chicken, I need to slice my chicken as thin (about 1/8 inch) and then tweak the poaching timing.

About as thin as I could get it to be

About as thin as I could get it to be

I decided to try 3 poaching timings, 1 minute, 45 seconds and 30 secondss but the chicken was clearly uncooked after 30 seconds of poaching so I ended up with just the 1 minute and 45 secs batches.

Poached chicken for velveting technique

Since we just had the Velvet Chicken with Asparagus not too long ago, I decided to use these Chicken in Cantonese style Mango Chicken, also from the Stir-frying to the Sky’s Edge cookbook.

Cantonese style Mango Chicken

Trial 2: Results

Disappointingly, neither timings resulted in chicken as silky and tender as the one I had in Golden House though the batch poached for 45 seconds was indeed superior than the 60 seconds poaching which resulted in overcooked chicken breast. So I’ve determined that the thickness of the chicken slices and the poaching timings both play a part in the end result but I still don’t think that my velveted chicken is as good as the one I’m trying to match :(. It might be possible that the restaurant utilizes the oil poaching method but according to Stir-frying to the Sky’s Edge the water poaching method results in softer pieces of meat. For my next trial (I dont have a strategy yet), I will taste test my chicken alongside Golden House’s so that I can be sure that I’m not trying to match an unattainable texture from my memory.