Balancing Citrus and Vinegar: Enter the Grapefruit Shrub

Every year with spring's arrival, my drinking patterns shift away from the barrel-aged bitter cocktails that highlight the dark winter months. I dust off my cocktail shakers and start shaking Daiquiris and Aviations, Sidecars and Pisco Sours. Then, it is just a matter of time before I am sitting on a patio whiling away the extended evening hours with a citrus-laden tipple. This year my horizons have expanded. Flavored syrups and citrus-based bitters have found their way into my at-home experiments, as well as vinegar, usually in the form of a shrub.

Fruit shrubs are perfect for spring, whether in a long drink, a cocktail, or even a nonalcoholic beverage. The vinegary bite adds unexpected depth to an otherwise ordinary beverage. Classic cocktails can be bumped up with a shrub's savory notes, and just introducing a splash of shrub to some soda water can create a truly refreshing drink that's perfect for summer. The best part is that they are incredibly easy to make, and nearly any fruit can be used. My first attempts were with blackberries, raspberries, and peaches. Last year, I tackled rhubarb. This year as I toured the produce department, I was overwhelmed by the choices. But when a friend threw down the ultimate challenge--citrus shrub--my sense of purpose was renewed.

Historically, there are two types of shrub and they are remarkably dissimilar. One is, at its simplest form, a sort of a bottled sour, usually consisting of some form of citrus, a spirit, and a sweetening agent. The other is a fruit syrup, usually consisting of either currants or berries, additionally flavored and preserved with vinegar. Before the days of refrigeration, people used fruit vinegars to cover the flavor of meat turning bad. But by adding sweetener to these vinegars, shrub was born. The widespread availability of ice signaled the end for shrubs, though many are preserved in many old cocktail guides. Current interest in different historical cooking techniques has vinegar-based shrubs primed for a comeback.

Part of this trend was inevitable as shrubs are just plain delicious. But because achieving balance in a berry shrub is relatively easy and can be accomplished with a very basic recipe, making shrub is simple. Vinegar-based citrus shrubs, though, are more challenging and rare because of the one additional ingredient, citric acid. The way the citric acid is manipulated in conjunction with vinegar's acetic acid can greatly impact the overall balance of the shrub. Too much of either and the result is undrinkable. But with a little care and attention, achieving a complex, tasty batch of citrus shrub is easily within reach.

Basic Recipe for Grapefruit Shrub*

2 good size grapefruits (mine were pink)
sugar [1 3/4 cup]
vinegar [1/2 cup sherry vinegar, 1/4 cup champagne vinegar]
pinch of salt

Procedure

Stage One: Oleo Saccharum

1. Peel the grapefruit avoiding white pith as much as possible.

2. Juice the grapefruit, measure it, and set it aside in the refrigerator. [1 3/4 cup]

3. Place an amount of sugar equal to the juice in a large bowl and add the peels. For 2 cups
of juice, use 2 cups of sugar.

4. Muddle the peels and sugar.

5. Set aside for at least 12 hours at room temperature. Note, I left mine for 2 days, and the flavor and aroma were incredible. The oleo saccharum will create a greater amount of depth than if you use just sugar and juice.

Stage Two: The Syrup

1. Combine the juice and the oleo saccharum.

2. Stir thoroughly until all of the sugar is dissolved.

3. Strain out the peels using a coarse strainer.

4. Add more sugar as needed to taste. This will depend heavily on the tartness of the grapefruit juice. Ideally, the syrup should still be tart but a bit sweeter than if it were completely balanced.

Stage Three: The Vinegar

Though this step really only comprises adding vinegar to your grapefruit syrup, it is the most crucial part. If you simply add all the vinegar at once, you could sacrifice all balance, leaving you with a syrup that is too vinegary.

1. Pick your vinegar. Think about what kind of flavors you want to highlight and what will pair well with your syrup. I used a blend of sherry vinegar and champagne vinegar, though it wasn't planned out ahead of time. Initially I chose sherry vinegar because grapefruit and sherry work well together in cocktails. Shortly after I started adding the vinegar, I noticed that the sherry overpowering the more delicate grapefruit syrup. Champagne vinegar is less strong and allowed the elements to come into balance.

2. Measure. Expect to use about half of your initial juice content. [approx. 3/4 cup vinegar]

3. Pour in a small amount of the vinegar, stir, and taste. This will give you an idea of where the flavors are heading. Starting with just a small amount before adding a bulk of vinegar will also help your palate adjust to what's going on in the shrub. Also, if the resulting flavor isn't what you were envisioning, you can still change vinegars.

4. Add more. Make this addition more substantial, at least half of what you measured [3/8 cup]. I added about half of my measured allotment before realizing it was getting too vinegary. Adding the champagne vinegar was more of a save than a plan. Sometimes this happens. Blend purposefully, take it slow, and pay attention to how each addition affects the overall balance.

5. Keep adding more vinegar until you are satisfied. Your palate will tell you when to stop. Trust it. 

6. Bottle and refrigerate overnight to let flavors marry.

*In order to make things a bit easier, I have added my own specific amounts in brackets to provide an example batch. Also note, by following these basic instructions, any citrus shrub is within reach. I myself made one with Meyer lemons.

Time for Rhubarb: A Recipe for Rhubarb Shrub

As soon as the days start to lengthen, I feel compelled to visit the farmer's market. Usually I just wander among the stalls to check out what's fresh and available. Sometimes, I come home empty-handed. But on days when the fruits and vegetables inspire me, I leave with bags full of ideas and produce. On one recent  Saturday morning, Tracy and I made our way over to the University District farmer's market. It was a pleasant Spring morning with the sun shining just enough to keep the morning chill mostly at bay. After some pastries and coffee, we began to take in the highlights. What caught my eye was the rhubarb, fat red stalks piled high. I wasn't sure what exactly to do with it, but I knew some of those stalks were coming home with me. Tracy's eyes lit up. too, and together we filled a small bag. When Tracy suggested that I make some rhubarb shrub, I instantly knew she was on to something--those stalks were destined to meet vinegar.

Every summer I make shrubs. I love their vinegary sweetness, and the beautiful way they preserve summer fruits for year-round consumption. In a way, winter seems a bit shorter with shrub around. Adding a bit of raspberry or apricot to a drink during those gray months is almost like magic. Almost. It's also pretty amazing how just a quarter ounce can totally change a drink, transforming its flavors into something new. Almost any fruit works in a shrub, and adapting the basic recipe is very easy. Usually on a whim, while I am roaming around the farmer's market, something stands out and it will be the newest shrub. This year, I seem to be starting with rhubarb.

In the past, I have always made hot-processed shrub, which entails simmering the fruit, sugar and water, and to a lesser extent, vinegar for a period of time. After cooling, you strain and bottle the resulting mixture and it's ready. Last year, I read about making shrubs without heat, which supposedly gives them a brighter flavor. I decided to attempt it with the rhubarb, and no exact recipe exists, I just adapted the different information I found online.  

Rhubarb Shrub

10 3/4 ounces (by weight) chopped rhubarb
10 3/4 ounces (by weight) natural sugar
10 3/4 ounces vinegar

1. Chop and weigh fruit.
2. Add an equal amount of sugar.

Notes: It doesn't matter if you use the same amount of raw materials that I did. Equal parts is the key, at least as far as a jumping off point. Fine-tuning may be required later. I chopped up the three stalks of rhubarb that I bought and then weighed the pieces. From there I just had to match proportions. After I added the sugar, I stirred it to coat all of the pieces. I also let it set for 15 minutes in the sugar so it would be easier to muddle. With a softer fruit this wouldn't be necessary.

3. Muddle fruit and sugar.
4. Macerate at room temperature for 24-48 hours.

Notes: Since rhubarb has the consistency of celery, I let the rhubarb macerate for 15 minutes before I muddled it. This allowed the sugar to start breaking down the toughness and made the muddling a lot more successful. Then I set it aside to macerate.

5. Add vinegar.
6. Cover and store at room temperature for a week.

Notes: When I added the vinegar, I also mixed it all up as much of the sugar had settled to the bottom. For the vinegar, I used mostly champagne vinegar as this is what I usually use for shrubs. Of course, I ran out, and had to add an ounce of apple cider vinegar to make up the difference. Then I covered the bowl with Saran wrap and put it back on the counter.

7. Strain mixture through a coarse or semi-coarse strainer.
8. Restrain through cheesecloth.
9. Bottle and store for at least more week before using.

Notes: Because I recently ran out of cheese cloth, and for some reason the grocery store was totally sold out, I bottled the shrub after the first strain. It needed to rest for a week anyway to allow the flavors to develop further. A week later, I strained the shrub through cheesecloth and rebottled it.

The real test of any shrub is in a drink. I know that when I taste tested the shrub it was mildly sweet and still quite vinegary. This would normally be the time for fine-tuning, adding sugar or vinegar to create a balance. But because I have never made this kind of shrub before, I wasn't sure if it was balanced. So instead of adding anything I just went with it. Here is a great aperitif recipe to use with any shrub--it is easy and delightful. I actually made it earlier in the Spring with blackberry shrub, and it was very tasty but it certainly was not as zippy and fruity as this aperitif was. I would highly recommend this as a great introduction to the glory of shrubs. Or you could make a rum shrub, which is quite nice as well.  

Sherry Shrub (as adapted from alcademics.com, who adapted it from Neyah White's original recipe)

3/4 ounce shrub*

2 ounces manzanilla sherry

Stir in a mixing glass three-quarters full of ice and strain into a small cocktail glass. Garnish with orange or lemon twist.**

*Of course, I used rhubarb shrub here. I have used blackberry shrub in the past.

**I used an orange twist on a lark. I was out of lemons. The original recipe calls for lemon twist. I was pretty pleased with the orange though.