So after a bit more thought I decided to try making carotene butter...in none of the ways that was suggested to me LOL. Anyways here are my steps.
Fermented carrots. PH was like 4.4. Juiced the carrots-got a terrible yield but I mixed it with some store-bought carrots juice. The leftover brine that the carrots were fermenting in was super delicious, so I added a bit of that too.
Fermented cream at 30 C over night. I actually let it sit out a day but it wasn't souring fast enough and I wanted to make it this weekend so I sous vided it. Turned to creme fraiche(?) super quickly.
Mixed the creme fraiche and carrot juice (with all the liquid) together. Then churned it in a stand mixer! Honestly I think this method (with or without fermenting) is easier than the ChefSteps method but my butter didn't turn out too carroty or anything. I'm not sure what it's supposed to taste like though. But the most delicious thing that came out of this butter making process was the buttermilk-most of the flavor is still in the leftover buttermilk so...idk. But the buttermilk is like super delicious.