Remember last Sukkot? The sound of cornstalks rustling on the roof of my car as I drove slowly home from Renton's farmer's market. The trees on our hills still bright with fading leaves. Carrying my lulav and etrog out to the sukkah in the rain-washed morning, and shaking them in all four directions as I dodged the raindrops still dripping from the sukkah's so-called roof.

And then, when the festival was over, my reluctance to discard the beautiful fragrant etrogim. They had come such a long way to reach us, just in time for the festival! So I peeled them, and poured vodka over the thin shavings of yellow skin, and set them in a cupboard to wait in the dark. At first the shavings sat at the bottom of a bottle of clear liquid. Over time, some alchemy transpired. The liquid became golden, the peel ever-more translucent. Now, some months later, they have been transformed from this:

Etrog, sliced open.

To this:

Before decanting.

I open the jar and am washed with a heady wave of the scent of etrog. Surely smell is one of the most evocative senses: one whiff and I'm transported back to the day before Yom Kippur when I first lifted last year's etrogim out of their foam cradles and brought them to my face to inhale their extraordinary scent. Nothing else smells quite like an etrog. It's lemony, yes, to be sure, but it's more than that. Richer, sharper, more complicated. Over the years I've experimented with etrog preserves, but no jam ever quite captures the way an etrog smells -- the way it makes me feel -- when I first press it to my nose before the festival begins.

But this etrogcello comes close.

A few weeks ago I made a Splenda simple syrup and added it to the jar, then returned it to the darkness. Yesterday, Tu BiShvat almost upon us, I washed out two plastic bottles and prepared them for their new contents.

The 2012 vintage.

We actually still have a couple of tiny flagons of last year's etrogcello left over. It's not as bright or as pungent as this year's stuff, though it's still tasty. I brought some to our Simchat Torah celebration last fall -- after we danced the Torah scrolls around the Williams College Jewish Center, when the traditional schnapps and vodka were brought out for toasting, I added a wee bottle of etrogcello to the table. It was a surprise, a special treat -- a little taste of Sukkot although Sukkot had just ended.

But really the reason I make the etrogcello is so that we can drink it at Tu BiShvat. The New Year of the Trees; the birthday, according to Talmud, of every tree, no matter when it was planted. The date when (our tradition says) the sap begins to rise to feed the trees for the year to come; the time when cosmic sap begins to rise, renewing our spiritual energy for the welter of spring festivals ahead. How better to celebrate Tu BiShvat than with this pri etz hadar, this fruit of a goodly tree, which we so cherished back at Sukkot? It stitches the harvest season to this moment in deepest New England winter. It reminds me that everything which has been dormant can once again bear fruit.

Tonight at our seder I will raise a glass: to the memory of last Sukkot, to the anticipation of next Sukkot, to the trees which bore this etrog, to the many hands which brought it here, to the Source of All from whom all blessings flow. L'chaim!