The Bright Magic of Citrus in the Baking Pan

http://www.nytimes.com/2017/03/07/dining/baking-with-citrus-lemon-orange.html

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When I was a child, we often spent our summers in Italy. My grandparents were Italian, and we’d stay with them in their house, in the hills outside Florence. It was complete madness for my dad’s family to still have the house — it was grand, crumbling and soaking up all available funds — but magic for us kids, of course, less aware of all the headaches.

A big part of this magic came from the vast and largely empty structure in the garden called the limonaia. In parts of Italy, limonaias — lemon houses — are where citrus trees in their terra-cotta pots are taken during the winter months to shield them from the unforgiving frost and heavy rain. On big citrus estates, limonaias would often be tall and elaborate buildings, built around imposing columns and cathedral-like as a result.

Once the frost had passed and the citrus trees were no longer in need of protection, they’d be returned to their groves, leaving the limonaia to sit empty through the summer. The appeal of that empty space — slightly creepy with its vacant pots and random vines growing wild on the inside wall — was enormous for my brother and me. We’d spend hours clambering around and hiding out, the smell of citrus still hanging vividly in the air.

The house is long gone from the family, and it’s been many years since I’ve been in a limonaia. Indeed, my brother, Yiftach, is also a memory for the family, taken from us before his time. The memory of playing in that large empty room with my brother, the smell of citrus still hanging in the air, is as sharp and vivid as a squeeze of lemon itself.

The memory of these summers lives on, in part, through the lemon tree my parents have growing in front of their house today, outside Jerusalem. The climate is one without frost, and so this tree is right where it’s been for over 20 years, unmoved, producing lemons for my parents at an insanely prolific rate. Whenever I’m there, we have the limoncello Mum has made from steeping lemon skins in alcohol and then adding sugar syrup, drinking it from shot glasses with — what else — little pictures of lemons on them. The clinking of our glasses and that hit of citrus brought by the first sip of limoncello marks the arrival back home.

Lemons, then, have become a bit mythical for me. They are with me every step of the way, and not just as a memory and a tradition, but as a source of so much of what makes me happy in the kitchen. They leave their bright mark all over my savory cooking: a final squeeze of lemon juice to balance a dish, some finely chopped preserved lemon skin to bring bursts of flavor and surprise, a few strips of pared lemon to infuse a stew. Lemon, for me, is what makes food sing.

Citrus in all its forms appears as often in my baking as it does in my savory cooking, even when it’s not shouting about itself. As with the limonaia during those summer months in Italy, citrus doesn’t always need to be seen for its presence to be felt. Sometimes, of course, the citrus is loud and clear: Limes and oranges are very much the lead act in today’s bakes, for example. Often, though, the role played by citrus is more of a supporting one and — if we define magic as that which brings about an effect without showing its hand at work — a little bit magic.

This magic can still be about scent and flavor: the grated lemon zest in a butter-rich pastry shell, or the subtle hint of orange zest in a batch of cranberry, oat and white chocolate cookies. It can be about the way citrus balances other flavors in a dish: the addition of lemon zest and juice in an almond paste, for example, to prevent it from being too sickly sweet, or the juice and zest of limes used to cut through the richness of a cheesecake. It can also, though, be about the huge utility of citrus in baking: its functional role as an acid and the effect it can therefore have on other ingredients.

Take the act of whisking egg whites to make simple meringues (or cakes or soufflés). For the egg whites to increase sufficiently in volume when they are being whipped, they need to be stabilized by the addition of something acidic. While cream of tartar is often used, a few drops of lemon juice per egg white works just as well. Or think of when lemon juice is added to apples or blueberries that are being cooked to make jelly or jam. To set, the gelling agent in fruit, pectin, needs to be coaxed out. A teaspoon or two of lemon juice is enough to make that happen.

Oranges and lemons are the workhorses of my kitchen, but I’ve barely scratched the citrus surface here — no mention of grapefruit or sour oranges, mandarins or the mottled skin and powerful scent of bergamot, bitter Seville oranges or Sicilian blood oranges, all kind of limes and yuzu or kumquats. If you do want to scratch further, then just one bit of practical advice: Whether you’re juicing or zesting or cutting out the segments of flesh to chop up, be sure to avoid the white pith in the membrane, which encases each segment. Crushing this will release a bitterness into the dish, rather than bringing the brightness and balance that citrus so beautifully provides.

Recipes: Rosemary, Olive Oil and Orange Cake | Lime, Mint and Rum Tarts | Rice Fritters With Orange Blossom Custard