Experimenting with @runpunkrun's lemon bars

[sonia]

As I commented to runpunkrun after I tried their Dairy-free Lemon Bar recipe, the bars taste good, but they differ from the unexpected canonical lemon bar in my head.

This personal canonical lemon bar has a crust more like shortbread, denser and softer at the same time, and more off-white. Filling creamier and less sweet. I have no idea where or when I had it, but the image of it is clear, complete with waxed paper under it from the bakery.

Things I have learned while experimenting with this recipe:

• I am an engineer, not a scientist. Obviously I should have changed one thing at a time and held everything else constant until I achieved what I wanted. What I did is use available ingredients and eyeball quantities and see how it turned out. At least I took some notes!
  
• My intuition about what to change works a lot better for the filling than the crust.
  
• The kind of oil matters.
  
• The kind of citrus matters.
  
• Buy an extra lemon. Not all lemons are equally juicy.
  
• My cat likes lemon bars. Who would have thought! I left a full pan cooling on the counter, and when I came back the top looked different... like it had been... licked???

Crust
I had bought some cassava flour on sale, so first I tried substituting cassava flour for the almond flour by weight. I knew almond flour absorbs less liquid by volume, but it turns out it absorbs less liquid by weight too. I ended up adding 1/2 cup of water to get the batter the right consistency. The crust turned out rubbery but edible.

The next time I put in half as much cassava flour, and still had to add water. Then I realized that I've been using the coconut oil that's been in the refrigerator forever as my neutral oil. I heated it in the microwave to make it liquid, but I think it was making the batter more dry overall. I switched to sunflower oil this last time.

I went back to mostly almond flour, even though it's not the consistency I want. I need to learn more about gluten-free flours before I try again. I did change the ratio of almond flour to cassava flour, and added an egg. The batter came out a little too moist, but the bars taste fine.

New ingredients (so far):
1 cup almond flour
1/2 cup cassava flour
1/8 cup powdered sugar
1/4 cup neutral oil (sunflower)
2 large eggs
zest from one lemon ~1 teaspoon
1/2 tsp fine salt (except what I have is coarse salt so I totally eyeballed this)

Filling
I wanted the filling to be creamier, less sharp, and less sweet. So I decreased the sugar, increased the GF flour, and added an egg, and used the same methods. That's been working great.

New ingredients:
1/2 cup granulated sugar
1/4 cup GF flour
1/2 (heaping) tsp baking powder
3 large eggs
1/4 cup lemon juice

I was tempted by Meyer lemons at the farmer's market one week, and Persian limes the next week. Turns out the Persian limes are sharper than I like. The Meyer lemons are great in this recipe!

I ran out of cassava flour and used tapioca starch instead, which is finer. Possibly coincidentally, it took a little longer to bake the filling.

Note to self: USE THE OVEN MITTS! One time I wasn't paying attention and just grabbed the hot handles of my glass pan to put the crust + filling in the oven. Fortunately I dropped the pan back on the stove top without spilling anything, and it had cooled just enough not to give me blisters.


If anyone has suggestions on how to get the crust more the way I want it, I'm all ears! Any gluten-free baking experiments you want to share?

Comments

[indywind]

for a more shortbready consistency of the crust, maybe try making it more like shortbread, using a greater amount of a fat that has liquid incorporated, no egg in the crust (maybe a bit of sticky rice flour, if you want more binding/stick-together-ness?), and little to no water? I'd go for at least 1/2 cup butter or margarine, at room temp or slightly cool, not melted; mix the dry ingredients together, then the dry mix with the fat til it's evenly distributed, probably sort of crumbly and maybe willing to stick together in clumps if you squeeze it. If it seems to be willing to stick together enough to be pressed into a layer on the bottom of the baking pan, do that; if it's not sticking together enough, sprinkle on a very small amount of cool water, like 1-2tsp, mix that in, and try again.

I need to revisit lemon bars now the Meyer lemons are all coming ripe on my relatives' trees and they're looking to unload the surplus on anyone who doesn't protest too much.
If I try this version I'll report how it comes out!

[sonia]

Hm, I will give this a try, thanks!

[jesse_the_k]

Let's hear it for recipe engineering in all its forms.

I just used coconut flour for a pumpkin bread recipe (details to come after a confirmatory second loaf) and I guess that coconut flout would add richness to the shortbread. It's thirsty as all get out--my first try would be 1 c almond flour, 1/2 c coconut flour and omit the cassava/tapioca element entirely.

But it's a guess!

[sonia]

Thanks! I bet that would be yummy.

[runpunkrun]

Thanks for sharing! I always find this process fascinating, what works and what doesn't.

One way to get a shortbread crust, like indywind says, is butter, but ghee (clarified butter) will also work, though with slightly different results. If neither of those is an option, solid shortening like Crisco or Spectrum's palm shortening will definitely work. Like with butter, you'd cut the solid shortening into the flour mixture using a pastry blender, two knives, or just your hands, pinching the fat into the flour until it's in pea-sized pieces. You could also cut your solid coconut oil into the flour this way (just don't use your hands because the oil will melt). Then you press the dough into the pan. It will be much drier, but it'll stick together if you have the right amount of fat cut in. This will give you a crust that has more pastry-like properties, like shortbread or pie crust.

One thing I find helpful when developing recipes is looking at a bunch of other recipes that have the kind of ingredients I want to use and kind of melding them together with guesswork. Here's a new lemon bar recipe from a food blogger I trust: Gluten-Free Lemon Bars with Almond Flour Shortbread Crust.

It uses butter in the crust, but you can sub solid coconut oil or shortening almost straight across. It also has a lemon curd topping.

[sonia]

Thanks! Wow, that is a lot of eggs and lemons in that new recipe! I will try butter or a butter substitute next time I make these.

[runpunkrun]

Lemon curd has a ridonkulous amount of eggs and lemons in it. Every time I think about giving it a try, I'm like, "...But that's so many eggs. And all that stirring."

[jesse_the_k]

I have the answer for almost every lemon curd need except lemon bars