Balsamic Strawberry Ice Cream!

The ice cream making saga continues! Nothing welcomes summertime like fresh strawberries! I've always found the combination of strawberries and balsamic vinegar rather odd, they never strike me as a likely match but here we are, a match made in heaven. Funny how things just work out. 

Granted I took apart this recipe and tried the strawberry + balsamic vinegar portion and made it into a fluffy light mousse weeks ago in my chiffon cake experiment but prior to that I've always looked at that pairing with questioning eyes. Vinegar with my strawberries?? Isn't it tart enough and to put even more sour in! That's just crazy talk! At least to me it was but then how come it shows up in everything? It must tastes good in order to appear together in so many things right?!? So as a curious little kitchen scientist, I decided it was time to test this odd coupling of ingredients. 

When I first tried it in the mousse I was more than impressed, not only did it not make the strawberries more sour but it enhanced it by bringing out the nature flavors of the strawberries. 

Food for Thought: [about 30 minutes of researching later...] Because this is how my brain likes to run, I was curious to why adding something acidic was important to a process like this, how did the balsamic vinegar make this so much better? I'm sure many of you have also seen lemon juice being added to recipes that create similar effects where it just makes things taste better somehow and why is that... So of course, I went to my many handy dandy (nerdy) reference books (On Food and Cooking: The Science and Lore of the Kitchen by Harold McGee and Cook's Illustrated The Science of Good Cooking). To answer that question, we have to go even further back. It turns out that adding sugar and acid go hand in hand. Have you ever noticed while working with some fruit related recipe that you always add in sugar? So why more sugar when the fruits themselves already have plenty? Well, sugar is hygroscopic which means it has an affinity for water molecules, in other words, adding sugar to the fruits will draw out the water (juices) from the fruit. This process is called maceration. By performing this procedure the fruit becomes softer because the water that was once there holding onto the fruit's structure has now been removed. In addition to the softer fruit you also get a nice reserve of the flavor-rich juice you've extracted from the fruit. So now what? Balance. This is where the acid comes into place. Acidity will help balance the sugar and prevent the dish from being overbearingly sweet so in the end you get the concentrated bright fresh flavors of the fruit. There you have it folks. Mystery solved, my brain is happy.

Balsamic Strawberry Ice Cream
from Sweet Cream and Sugar Cones by Bi-Rite Creamery

Ingredients:
For strawberry puree:

• 3 cups of strawberries, halved or quartered
• 2 1/2 tbsp sugar
• 2 teaspoon of balsamic vinegar 

For ice cream base:

• 5 large egg yolks 
• 1/2 cup sugar
• 1 3/4 cups of heavy cream
• 3/4 cup 1% or 2% milk
• 1/4 tsp salt
• 2 teaspoon balsamic vinegar

Procedures: 
For the puree:

1. Combine berries, sugar, and vinegar in a nonreactive skillet. While stirring, cook over medium heat until strawberries are soft and the liquid they released is reduced (approx 6-8 minutes)
2. Transfer berries and their juices to a blender/food processor and puree. Set aside.

For the base:

1. In a medium heatproof bowl, whisk the yolks just to break them up, then whisk in half of the sugar (1/4 cup), set aside.
2. In a heavy nonreactive pan, stir together cream, milk, salt, and the remaining sugar and put the pan over medium-high heat. When the mixture approaches a bare simmer, reduce heat to medium.
3. Carefully scoop out about 1/2 cup of the hot cream mixture and, whisking the eggs constantly, add the cream to the bowl with the egg yolks. Repeat, adding another 1/2 cup of the hot cream to the bowl with yolks. Using a heatproof rubber spatula or wooden spoon, stir the cream in the saucepan as you slowly pour the egg-cream mixture from the bowl into the pan.
4. Cook the mixture carefully over medium heat stirring constantly, until thicken (this part is tricky, because it doesn't get really thick just thick enough so that the mixture coats the back of the spatula and when you run your finger along it, it holds a clear path) and then cook for another 1-2 minutes longer (don't over cook otherwise it becomes grainy and egg-y in flavor)
5. Strain the base through a fine-mesh strainer into a clean container. Set container into an ice bath, using a clean spatula, stir the base occasionally until it becomes cool (or you can stick it in the fridge and stir it every 5 minutes until completely cooled). Remove from ice bath and cover with plastic wrap and refrigerate the base for at least 2 hours or overnight
6. Add in the strawberry puree and teaspoon of balsamic vinegar to the chilled base and freeze in ice cream machine according to the manufacturer's instructions.