Milk Kefir would have to be one of our favourite ferments. Thick, creamy and tangy, it's similar to yoghurt in consistency and only takes 5 minutes to make. No heating or incubating required woohoo! It's super powerful and is packed with more than 30-40 different types of beneficial bacteria and yeasts so take it slow at first and gradually increase your intake.
To make this you will need to get your hands on some milk kefir grains. These are a naturally occurring culture that looks similar to cauliflower florets or cottage cheese. Ask someone you know who ferments or even check out gumtree. Many people are willing to pass on their cultures for free or a small price. You only need a small amount to start, they grow quickly and you will soon find you have an excess of them.