Making lemonade is only part of the story.
Those pips that you usually throw away after the lemonade is made and drunk and forgotten. Take them and wash them. Now very carefully take the outer skin off. Expect to lose a few at this stage, because fat fingers, clumsy thumbs, nature being an arse. Then, still gently, put them between two layers of wet kitchen paper and fold into a little package that you can fit into a ziplock bag. Put the ziplock bag somewhere warm and dark (mine went in the airing cupboard) for a few days. When you check on them, you'll see that again, you've lost a few, maybe you've just got two left that are still whole seeds and have a tiny sprout coming out of them. Take these little lovelies and pop them in a pot of compost, water well and keep them on your window sill. Keep it from drying out and just wait. I can't remember exactly how long it was, but this little guy and his sister popped up after a week or so. They're a much deeper green than anything else we have.
They'll need a little while longer being looked after indoors before we find a space for them in the garden. But then we'll have a lemon tree and, with another few years of care, some lemons.
Never considered growing citrus in the UK but Google looks to confirm it's doable. Might have to give it a go.
neither had I till now! The evidence for me is that it works so far in a pot on my windowsill. Early days!
Good luck with your lemons. With global warming we may develop the climate for them.