Infusing flavor into your gelato custard

Infusing flavor into your gelato custard:

Mint, walnut, rosemary, vanilla, cinnamon, brown butter, oatmeal, any herb, any nut, any spice – Custard can be infused with so many flavors. 

How does the custard take up these flavors?  Through heat, time and maceration.  Heating the cream-milk mixture with herbs, spices or nuts and simmering them in the custard for a short period is how flavor is extracted and infused. 

As a home cook, you might prepare one or two flavors at time.  If you are making lemon verbena ice cream, you would cook and thicken your custard with lemon verbena leaves.  When I prepare two to four bases for a Sweetcycle event, I also infuse each base separately, for example, adding walnuts, honey and rosemary to one and mahaleb and rose to another. 

In a scoop shop or gelateria, the health code mandates that ice cream or gelato custard must be pasteurized and kept cold until it is churned. A small scoop shop might flavor and churn 10 gallons of ice cream every other day, at the very least.  It is neither cost effective nor time/labor efficient to cook and infuse flavor into each gallon separately.  And then chill and pasteurize each flavor separately.  (Most scoop shops don’t even own pasteurizing machines; they buy unflavored ice cream custard from a large dairy).  Once a scoop shop begins to work with pasteurized base, they cannot reheat the base to flavor it.  They use cold or room temperature flavorings like chocolate syrup, coffee syrup or extract, mint oil, or vanilla bean powder.  If they want to use real bananas instead of banana extract or flavoring, they roast the bananas, puree them and chill them, adding them to the base once they are chilled. 

So mint gelato or honey-pecan-lavender ice cream in an ice cream store or gelato shop simply cannot have the same flavor profile of a single batch of gelato base made on a small scale by heating the mint in the cream or heating the pecans, and lavender in the cream.