How to sterilise jars and milk buckets without chemicals

Raw milk is an important food to my family, so much so that we didn’t mind buying all of our goats’ feed in while living in suburban sized blocks with no grazing land. To make the most of this precious milk, and to make sure that there’s no chance of us getting sick, I am careful about having a milking routine that minimises the chances of the milk getting contaminated.

How to sterilise jars and milk buckets without chemicals: oven method

As soon as I’ve poured milk into the jars that I’ve sterilised the day before, I wash my stainless steel milking bucket, stainless steel funnel, and cotton straining cloth with cold or lukewarm water, making sure that all the milk has been removed from them.

I place it all upside down in the oven (except for the cloth), and fill the rest of the oven up with any jars that need sterilising, placed upside down as well (I rinse these jars in lukewarm water as soon as they’re empty, if you leave them sitting around with a tiny bit of milk in them it will be very difficult to remove later). I switch the oven on to 110ºC (230ºF) and leave it to heat up.

I bring a small pot of water to the boil for the jar lids. When it’s boiling I add the lids and boil for around a minute, then drain the water from the pot and put the lid back on. 

When the oven has heated up, and there is no water remaining on the jars and they are hot to the touch, I turn the oven off and put the jar lids in there to dry. When the oven has cooled down, I take the jars out, put the lids on them, take the milking bucket, put the funnel inside it and cover it with the lid.

The lids stop bugs and bad bacteria from getting into anything that will touch the milk. Some books I’ve read say to store the bucket upside down to achieve the same thing, but I find having a lid to be really useful, not just for storing the empty bucket, but also for carrying the milk into the house, and for just making sure nothing gets into it in between goats, of if there’s some emergency or another that needs seeing to during milking time.

As for the straining cloth that I mentioned earlier, some people use disposable filters, I don’t. I use a bit of cheesecloth and hang it on the washing line to dry after rinsing, and then before I milk, I bring some water to the boil, put the cloth in it, and boil for a minute, then I tip some water out of it and leave the lid on the pot, to stop anything else getting to it. To strain the milk, I put the funnel over the top of a jar, cover the funnel in the cloth, and pour the milk in.

Once the milk is in the jars and the lids are on, I put them in the fridge, surrounded with ice, to chill them quickly.  When we were moving house and I didn’t have a fridge or ice I just kept the milk at room temperature and used it within a day without any problems. If you leave fresh raw milk at room temperature for longer it will start to thicken and turn into cheese.

Off-Grid 2026 update: scalding hot water method

This method works well if you have a wood cookstove and can’t easily control the oven temperature, or if you don’t have an oven. It’s only suited to sterilising jars that you’re going to use in the next day or so.

To sterilise jars with boiling water, first rinse them in cool or hot water. If you put boiling water straight into a dry jar, it is likely to break.

Put your jars on a dry wooden surface or a dry towel.

Next make sure your water is very hot, but not at a rolling boil. If it is at a rolling boil, take it off the boil for a few minutes. Water at a rolling boil can sometimes break jars.

Carefully pour a small amount of this scalding hot water into your jars, fillling them between 1/8 and 1/4 full. Put the lid on and shake them to get the boiling water to coat all insides of the jar. Tip the water out, put the lid back on, and leave it alone until it’s time to use your jar.

For the milking bucket, once the bucket, lid, funnel, and cheesecloth have been cleaned, I run boiling water all around the edges of the bucket and the inside of the lid, put the funnel and cheesecloth inside it, and cover these with the scalding hot water too. The lid then goes on, and the bucket and milking gear are ready to use any time the next day.

Is it necessary to sterilise milking equipment?

Some people say yes, others say no.

The reasoning behind the people who say yes is that it’s important to do sterilise milking equipment in order to minimise possible sources of contamination that might ruin cheeses or make people sick. The people who say no are often looking at traditional cultures around the world, and the historical use of wooden milking equipment which was not sterile and instead was filled with beneficial bacteria.

We can encourage the kinds of bacteria beneficial for cheesemaking by avoiding toxic cleaning products and using only edible cleaners such as water, salt, lemon juice, and vinegar.

Salt, scalding, and sunlight were used on milking gear in some traditional cultures before the modern “all bacteria must die” approach began.

For me, it’s all about what is practical: I don’t always sterilise my milking gear. When we go out for the day, we don’t usually light the woodstove, so I have no way of sterilising anything that night. The next day, I just wash everything right before milking, and the milk is fine for drinking that day, and for making fast mozzarella, ricotta, paneer, and yoghurt.

When we do have the stove going, I take the effort to sterilise the jars, funnel, cheesecloth and milking bucket, because aged hard cheeses are an essential staple food for us, and I want to reduce the chances of anything unwanted getting into my cheeses and ruining a batch. Maybe this isn’t necessary, but honestly, it doesn’t take much time, and I’d rather take that extra effort as an extra precaution to make sure that my cheese is good.

My cheeses are alive and filled with good bacteria from using raw milk, homemade natural cheese cultures, and natural rind aging on wooden surfaces, and I don’t think sterilising the bucket and jars with boiling water negatively impacts my cheesemaking in any way.

Is it necessary to sterilise canning jars?

When doing the Aussie “hot jar, hot lid, upside down” method of getting jams, chutneys, and pickles into jars, having hot sterile jars and lids is an essential part of how that method works.

When doing water bath canning or pressure canning, my understanding is that the jars get sterilised during the canning process, so I do not sterilise jars before canning. Some people do sterilise their jars before canning though, so whether you do this or not is up to you.