With strawberry season in full swing, I was passing by a fruit stand the other day when the intoxicating aroma of strawberries led me to a stack of strawberries which had just been marked down to ¥500 (about $4.20 USD) per case. The reason? They were all different sizes, a big no-no in quality conscious Japan. They also weren't the sweetest variety available, but since it was their sweet aroma that drew me towards them in the first place, I knew exactly what I wanted to do with them. Two cases of strawberries in tow, I stopped by the liquor shop on the way home and picked up a few bottles of mid-grade vodka to make a strawberry liqueur.
Fruit like any plant material is just a matrix of cells, each cell is like a juice carton filled with esters and terpenes (amongst other things) which gives each fruit their distinct aroma. When you bite into a fruit, these cells rupture, releasing their juices and accompanying aroma. When you're making an infusion, the goal is extract the juice without pieces of the carton. This rules out pressing, blending or otherwise physically assaulting the berries in a way that would cause plant solids to get released into our infusion.
The traditional way of extracting flavor is to soak the fruit undisturbed in a high proof alcohol for a long time. It takes a long time because like a juice carton, the cell walls keep their contents under wraps. This is why it's important to use a high proof alcohol, to keep the fruit from spoiling. The other reason for using alcohol is because it's a solvent, which is very good at dissolving the aroma compounds in fruit. The problem is that with delicate fragrances like strawberry, the flavor compounds tend to break down over time, changing the flavor profile along with it. This is why most strawberry liqueurs taste more like strawberry jam than fresh strawberries.
So how do you get a great infusion in a short amount of time? Well the fastest method is to drop the berries into a chamber vacuum and draw a vacuum. By reducing the air pressure outside the fruit, it causes the microscopic air pockets inside the fruit to expand, rupturing the cell walls in the process. When the vacuum is released and the pressure is returned to normal, the now porous cells are free to vacate their contents into the empty spaces where the air used to be. This makes it easy for the alcohol to do it's job and extract the fruit's essence in a matter of days, rather than weeks.
Since I'm guessing most of you don't have a chamber vacuum at home, I've come up with the alternative method which works just as well and doesn't require any special equipment. All you have to do is freeze the berries in a regular home freezer. Instead of using air pressure, this method relies on the ice crystals that form in the berries as they freeze, to rupture the cell walls. While this kind of large ice crystal growth is undesirable when you want to defrost something and not have it lose a ton of its juices in the process, it's exactly what we want to happen for our infusion. This is why a home freezer and its slow freezing time is so well suited for this.
The resulting liqueur is ruby red and crystal clear with the heady aroma of a sun-drenched strawberry patch. Stirred into a pitcher full of ice and lemon juice, it makes for a delightful brunch-time strawberry lemonade. Mixed with a bit of cream, you get a heavenly strawberries and cream liqueur that's the perfect accompaniment for some after dinner truffles. Served on the rocks, with a splash of soda and you have a fantastic strawberry cocktail.
Best of all, the strawberries are still usable after they've done their work infusing the liqueur. Once you've poured off the liqueur, the berries can be pureed and cooked down with some sugar and lemon juice to make a strawberry preserve. You can also blend them with some ice to make a slushy alcoholic treat, or serve the berries whole over vanilla ice cream.
- Wash, dry and then trim the stems off the berries and freeze overnight.
- The next day, put the berries in a large glass jar and top with the rock sugar.
- Pour the vodka over the berries and leave in a cool place for a minimum of 2 days and a maximum of 5 days.
- Pour the strawberry liqueur into a bottle for storage. I recommend storing your liqueur in the refrigerator to prevent the flavor from changing
Since we're not eating these strawberries it doesn't matter if they're sour or misshapen. What does matter is that they taste like strawberries. Decades of selective breeding for size, frost and pest resistance have resulted in strawberries that are often bland and flavorless. I find that smaller berries from farmers markets work much better than the large commercial variety. If you can't smell them as you walk by, don't buy them.