Clean and sterilize six half-pint jars, lids, and bands in a water bath canner with a jar rack (I use a

Granite Ware 21.5-qt. Canner with Jar Rack). I sterilized while I was making the jam (boiling the jars for 10 minutes, and the lids for the last 5 minutes of that). Keeping the jars in the pot of hot water will keep them warm, which means they won’t crack when you add the hot jam later. Plus with the water already heated, processing the jam goes all that much quicker.

Transfer the strawberry mash to a very large stock pot (mine is 12 Qt–you want to be sure that no hot jam boils up onto your skin) and stir in the pectin. Add the Kerrygold butter to reduce foaming, then drop in the vanilla bean (cut in half and sliced lengthwise). Cook on medium heat until bubbly, stirring constantly with a heat-resistant silicone spatula. Once the mixture is at a good boil that isn’t stirred away, add the granulated sugar, stirring thoroughly. Allow the mixture to reach a full rolling boil again and then let it boil for a minute, stirring constantly. Remove from heat and skim foam, if necessary. Remove vanilla beans and scrape the insides into the jam as best you can. (You can rinse the beans and save them for another use or discard.)

Ladle hot jam into jars fitted with a funnel, leaving 1/3″ head space for processing. Rub the rims of the jars with a damp, clean cloth to remove any splatters. Attach lids and return to the water bath canner, making sure the jars don’t touch each other or the bottom of the pot (that’s what the jar rack is for) and that there is at least one inch of water over the tops of the jars. Bring the water bath canner to a full boil and then process the jars appropriately for your altitude (where I live, that means 5 minutes–though I boiled for 5 minutes and then left the jars in the canner for another 5 minutes after I turned off the heat, just to be safe). My source recommends processing for 5 minutes for 1001 to 3000 ft elevation, 10 minutes for 3000-6000 ft elevation, and 15 minutes for 6000-8000 ft elevation.

Remove jars from water bath canner and set on a wire rack to cool 12-24 hours. At that point, check the lids to make sure there is no give in the center: this lets you know that the jars are sealed. If a jar did not seal, put it in the fridge and use within a month, just to be safe. You can remove the bands for storage, but I leave them on. Stored in a cool, dark place, the jars should be shelf-stable for up to one year. If you seen any signs of spoilage down the road (lid gives in the middle or something just doesn’t look or smell right when you open it), DON’T SAMPLE IT. Throw it away. Your health isn’t worth the risk.