Please choose the correct solution to the question: How to make butter in a jar?

Solution1: Fill a jar halfway with heavy cream. Shake until the curd separates from the whey. Discard the whey and then refrigerate the curd.

Solution2: Fill a jar completely with heavy cream. Shake until the curd separates from the whey. Discard the whey and then refrigerate the curd.

Answer format: solution1/solution2
Answer: solution1