Finely grated zest of 4 lemons
3/4 cup (175 mL) fresh lemon juice
3/4 cup (175 mL) granulated sugar
3½ cups (875 mL) 35% cream
1/2 vanilla bean, seeds scraped and pod reserved
10 large egg yolks
In a saucepan, combine the lemon zest, juice, and 1/4 cup of the sugar.
Simmer until reduced to 1/2 cup; set aside to cool slightly.
In another saucepan, combine the cream, 1/4 cup of the sugar, the vanilla seeds and pod, and bring to just below boiling.
In a medium bowl, beat the egg yolks with the remaining 1/4 cup sugar until smooth.
Slowly whisk the hot cream into the yolks; stir in the lemon syrup and strain through a fine sieve.
Pre-heat your sous-vide bath to 174ºF
Skim any foam from the surface and divide the mixture among 6 sealable Mason jars.
Cook sous vide for 1 hour
***You are only 'sealing' this so you can cook them submerged in the sous-vide water - these are not 'sealed' in the sense that are shelf stable, or storable for more than a few days in the fridge.
Tip: You're using a whisk.... but don't whisk the mixture, you don't want to incorporate too much air.