Remove the skin from the bletted medlars and transfer into a pan with the water.
Bring to a rapid boil and simmer for 15 minutes or until the medlars are soft and pulpy.
Pass the medlar puree through a colander (not a sieve)
Once the seeds are out, transfer the pulp back into a pot with the sugar over medium heat.
Keep stirring throughout this process as the medlar pulp will jump. Be careful as the medlar butter thickens, it will be hot and can cause severe burns.
As the syrup thickens it will change colour. If you have a temperature probe or a jam thermometer you can measure the temperature to 85º to 90ºC. If you don't, please have a look at the video, it shows the thickness you should achieve. read more in the recipe notes below.
Once ready transfer to sterilised bottles and seal the jars shut once the contents has cooled a bit.
The nutritional information is for guidelines only, generated by the Spoonacular API.The nutritional values are for the total yield of 1.1 kg of medlar butter.