Well, here in the UK you cant get tinned butter “ at all. Ghee and clarified butter is around tinned at a huge price but not proper butter. Well, time to do it myself!
I decided to do a test can of 2lbs (1kg) of butter.
I believed this would need about two pints of jar space “ I decided to use two of the wide / low…Le Parfait"sprung sealable preserve jars and a couple of small jam jars in case my measurements were wrong. Mason Jars, Kilner Jars or any other airtight preserve jar should work fine
These need to be sterilised and heated. Warm the oven to 120C (250F), remove the seals and anything likely to melt and put the jars in (I tend to stand them in a baking tray for easy removal). Leave them in for 20 minutes. If you do the rest of this procedure right and start now on the butter, they should be done at the right time.
Now for the butter. I have heard that you should not used churned, oil added or…"spreadable" butters for this, so I stuck to 4 half pound slabs of hard English butter.
You will need a large wide pan, a wooden stirring spatula and some way of transferring hot butter into the jars. I used a ladle here, but for small jars a jam / canning funnel would be a big help.
Put all the butter into the pan and set the pan to a low heat, you want it to melt, not burn
As the butter melts, keep moving the slabs and stirring the melted butter. As it melts, the butter separates into clarified butter and solids. The solids will sink to the bottom and burn if you don't stir regularly.
When the butter has all melted, you need to simmer it gently for about five minutes. Keep stirring it will separate again if you don't.
After your butter has simmered for five minutes, your cans should be done. Remove the butter from the heat and take the cans from the oven. The cans will be HOT “ I use a pair of metal tongs to handle them “ its easier than oven gloves. Then don your oven gloves (I have a pair of knitted heat proof gloves that come in handy here) and re-fit the seals to the jars.
By now your butter will have separated again. Give it a good stir. Use your ladle (and funnel if needed) and transfer the butter into your jars. Leave about ¾" of head space so the jars can be shaken as they cool.
Seal up your jars. You can see here that the butter will separate again quickly. As the butter cools you need to keep shaking to keep it mixed.
Shake every ten minutes until the jars are only faintly warm to the touch. Then move the jars to the fridge. Shake every 5 minutes as the final rapid cooling takes place. When they finally set, the butter will look as it did originally, but is sealed in an airtight container.
I'm told that the same effect can be achieved with hard margarine if that is your preference. These jars will be stored in a cool dark pantry - fortunately its easy to tell if butter has gone rancid. I'll test the small one after the summer and the larger ones over time to check longevity.