In a medium saucepan place lemon juice, lemon rind, butter and sugar. Heat, stiring occasionally, over a medium heat until the butter has melted and the sugar has dissolved.
In a bowl, place eggs and additional egg yolks and whisk until combined.
Whisking the eggs, slowly pour in the lemon mixture. It is important to keep whisking while you do this.
Strain the lemon curd mixture through a sieve back into the saucepan to remove any “eggy bits”.
Cook over a low/medium heat until the mixture has thickened and coats the back of a spoon. At low heat this can take as long as 10 minutes. At medium heat it can take as little as 5 minutes.
Be careful not to overheat and overcook the mixture – you will then have lemon flavoured scrambled eggs. I like to not risk further cooking of the curd by immediately placing the saucepan into ice water to stop any further cooking. Stir regularly while the curd cools. You could also pour the lemon curd into a jug or bowl if the saucepan is particularly hot to stop overcooking.
Once mixture has cooled place in a sterilised jar and store in the fridge. Lemon curd will last for a couple of weeks in the fridge and it can be frozen.
For tangier lemon curd:
Add up to an additional ¼ cup of lemon juice.
Reduce the sugar slightly.
Follow my top 7 tips to making the best ever lemon curd.
Use fresh lemon juice not bottled.
Buy good quality butter and free range eggs.
Lemon juice can react to some metals such as aluminium, copper and iron so be sure to use a stainless steel saucepan.
Since cooked egg is the enemy of delicious, homemade lemon curd, it is important to heat the mixture slowly and over low/medium heat. You can use a double boil or a glass bowl over a pot of simmering water. However I find that this curd recipe can be successful made without a double boiler. You must be careful not to overheat and don't leave the lemon curd even for a second.
That leads me to the next tip - never allow the curd to boil. If you notice it getting to hot, remove the pot from the heat, stir well then return to the heat.
Have a large bowl of iced water nearby just in case you have to arrest the cooking quickly by plunging the pot base into the iced water.
When the lemon curd is ready, pour into a bowl or jug to cool. If you leave it in the saucepan to cool, you will risk overcooked lemon curd.