Wednesday 3 April 2013

{Ratio Rally} Lemon Bars

Spring begins early here. I started noticing it on my morning walk several weeks ago; the air was still cold and dry, but there were little hints all around me that it wouldn't be that way for too much longer. Even when many parts of the country were covered in snow, here the trees had already begun to bud. Clusters of little wildflowers sprung up, tiny dashes of violet and white accents scattered throughout the patches of green that were spreading over the ground. The fresh, bright green means that winter is ending, but - to me at least - yellow is the color that means spring has arrived for good. Daffodils, forsythia, and little wild buttercups, all a cheery lemon yellow.  

Perhaps that's why lemony treats are so popular this time of year. After another not-quite-perfect batch of hot cross buns last weekend left me tired of zesting lemons and oranges, I went looking for a less complicated Easter bread to make...only to find that nearly every traditional Easter bread required just as much zest! It's true of course that citrus fruits are some of the only things in season in these chilly months, and their fresh bright scent is welcome after a winter of rich and hearty foods. Yet oranges, limes, and grapefruit don't seem to be associated with spring baking quite the way lemons are - I like to think it's at least partly due to their vivid color, bright and welcome as the sunshine that's warming the ground back to life. 

Lemon bars are one of these quintessential springtime sweets. They also happen to be one of the treats I've missed most since I've been gluten-free, so when I saw Meaghan at The Wicked Good Vegan had chosen shortbread for this month's theme, I knew just what to do! I hadn't had a lemon bar in more than 5 years...until making these, that is! These are every bit as good as the ones I remember - tart and luscious lemon curd on top of a buttery, not-too-sweet crust. 

They are so simple to make, too. I would say it's "easy as pie," but this is actually easier than pie - it's as easy as "1-2-3"! Really, that's the ratio: 1 part sugar:2 parts fat:3 parts flour. For this particular recipe, 1 part = 85 g, but as with other ratio recipes, you can scale it up or down as long as you keep the proportions the same.

A few notes before we begin:
Because the shortbread crust is so simple, the quality of your ingredients is important - for the most flavor, try to find cultured or "European-style" butter from grass-fed dairy (one common brand is Kerrygold). Likewise, you will taste the flours more than you would in something with lots of other flavors such as brownies or gingerbread, and because there's very little moisture in the crust, you'll notice the flours' texture more too. Keep these things in mind if you want to substitute one of the flours! I'm lucky to have a local source for chestnut flour, but I know it might be hard to find in some places - if you can't find it, you might try sorghum flour or more millet flour as a substitute. 

This same shortbread recipe can be made in an 8x11 pan or a 9x13 pan, depending on whether you like a very thin crust or a more substantial crust. (The bars in the picture were made in an 8x11.) However, you'll notice there are two recipes for the lemon curd topping depending on which size pan you use, so you can have a nice thick lemon layer regardless of how thin you want the crust to be. (Sorry about the grainy picture quality - I was dealing with less-than-optimal photography conditions, to say the least!)

Shortbread Crust
160 g tapioca starch
50 g almond meal
25 g millet flour
20 g chestnut flour
1/2 tsp Pomona's citrus pectin
3/4 tsp salt
85 g sugar
1-2 tsp lemon zest
170 g high-quality unsalted butter, slightly softened

The brown flecks are from the almond meal; use blanched almond meal if you prefer a smoother appearance.

Lemon Topping
If using 8x11 pan:
140-160 mL lemon juice (around 2/3 cup)
300 g sugar
30-50 g tapioca starch
4 eggs, at room temperature
1 T or more lemon zest
Powdered sugar, as needed, for decoration after baking
If using 9x13 pan:
210-230 mL lemon juice (not quite a cup)
450 g sugar
45-75 g tapioca starch
6 eggs, at room temperature
1 1/2 - 2 T lemon zest
Powdered sugar, as needed, for decoration after baking

Mix the flours, pectin, and salt in one bowl, and mix the zest into the sugar in a smaller bowl. Cream the sugar-zest mixture into the butter until well blended (use paddle attachment if using stand mixer). Gradually blend in the flour mixture until dough forms a ball, scraping sides of the bowl occasionally. (If the dough is very soft or paste-like, you might want to chill it briefly before shaping - it should be stiff enough to handle.) Press the dough evenly into the baking dish with your hands and bake for 20-30 minutes, depending on thickness, until lightly browned and flaky. Let it cool somewhat before adding the topping - it will firm up as it cools, which will prevent the liquid from soaking in too much.

Meanwhile, mix up the lemon topping: Combine sugar, starch, and zest, then beat in the eggs. Gradually add the lemon juice and mix until smooth. Don't whip a lot of air into it though - it should be like custard, not foamy! Pour the mixture evenly over the crust and return to the oven for another 20 minutes, until topping is set. Don't worry about the browning - that's what the powdered sugar is for! Make sure the bars are completely cooled before dusting with powdered sugar and slicing - mine are a bit messy-looking at the edges because I was a little too impatient (it may help to chill them first). 

Store bars in the refrigerator.


  1. I have always wanted to make lemon bars, and I am truly glad someone did for this challenge.

    These look A-freaking-MAZING, Meg. Your recipes always do.

  2. I'm with you on the lemon this time of year! So springy!

    Lemon bars are kind of dangerous, though—the curd is so creamy and fresh, and the crust so crumbly, that it's easy to pretend that you're eating nothing before you snap out of it in time to remember to save at least half of the batch…


  3. I love the combination of flours you use in this crust, and I still have a few errant Meyer lemons bashing around in my refrigerator . . . I know what I'm making this weekend. What a lovely recipe!

  4. My goodness - this post certainly made my mouth water. [sheepish grin, dabbing at corners of mouth] Lemon bars used to be one of my favorite desserts, but I haven't had them in several years. With your recipe in hand, that may be changing soon.... :)