Harvest your lilacs as soon as the dew has dried, ideally mid-morning. You don't need much - one stem should be plenty. Carefully remove the blossoms.
Spread the shea butter onto a piece of parchment paper and place into a lidded container (a glass kitchen storage container or lidded casserole dish are great).
60 grams refined shea butter
Gently press the lilac blossoms into the shea butter, making sure no green stems or leaves are mixed in. You need just enough to cover the fat.
Lilac blossoms
Place the lid on the container and set aside in a cool, dark place for 24 hours. Remove the blossoms and smell the shea butter. If it hasn't taken on the lilac scent, repeat the process until it has. If the blossoms are too difficult to remove, very gently melt the shea butter and strain through a fine sieve to remove.
Once the enfleurage has reached the scent you'd like - note that it will never be as strong as an artificial perfume - remove the blossoms for the last time and transfer the shea butter to clean containers to store. It will keep for about a month in a cool, dark place.