Bring a very large pot/drum of water to the boil.  Meanwhile sterilise enough clean 750ml beer bottles to hold the passata.  Have new lids on hand ready to seal your bottles.  

Carefully place the tomatoes into the boiling water.  When the water returns to the boil, boil the tomatoes for 3 minutes.  This makes them easier to pass through the passata machine. 

Turn off the heat and carefully remove the tomatoes from the water and allow them to drain.  

Pass the tomatoes through a passata machine, either hand cranked or motorised to remove the seeds and skin. I pass the tomatoes through the machine at least twice, to ensure every bit of goodness is collected. 

Place a basil leaf in each bottle.  Fill each bottle with passata carefully using a funnel. 

Using a beer bottle sealing machine, seal the bottles. The sealing process is very important because if the lids come off all of your hard work will be ruined. 

Fill a very large pot/drum with water. Wrap each bottle in a tea towel and secure with kitchen string.  This will prevent the bottles bumping together and breaking during the boiling/preserving process. Lay the bottles carefully on their side in the pot of water.  Bring the water to the boil and boil the bottles for 40 minutes.  Turn the heat off and allow the bottles to cool completely in the water.  

Carefully remove the bottles and remove the tea towels. Wipe the bottles clean if necessary.  Label bottles and store passata somewhere dark and cool. Use passata throughout the cooler months for pasta, stews and pizzas.