Add all ingredients to a large crockpot, stirring to combine.
Set crockpot to LOW and crack the lid to let the water evaporate out. Let it cook. The idea is to cook out most of the liquid so it thickens.
After several hours (I left mine overnight), check it, stir it, taste it, adjust.
If it is still holding liquid, cook it longer, stirring, checking, tasting, and adjusting occasionally.
When it seems thickened to your preference (“spreadable” maybe), spoon it into containers for the fridge, or prepare to can and preserve…continuing to the next step --.
Bring a large canner pot to a boil and add sterilized jars.
Bring one jar and a 2 piece lid out of the hot water. Fill jars to ½” of top. With a chopstick or similar utensil, stir and move the butter around in the jar, removing air pockets and bubbles. Then, tap the bottom of the jar firmly (but don’t break it for gosh sakes!) on a towel on the countertop a few times to tamp down the butter.
Wipe any gunk off the rim and screw on 2-piece lid until finger tight. Place jar in water and repeat until the butter fills the last jar. Leftover butter can be put in a jar and into the fridge. Try to do these steps swiftly.
Cover the canner, bring water back to a boil, and process jars for 30 minutes. Remove from water carefully, and let cool.
You may hear popping as the jars cool. Leave them be! Don’t shake or jostle them for 24 hours. After that, check seals- lids should be sucked down. Any jars that didn’t seal can be refrigerated.