There are no medieval equivalents to YouTube channels, since YouTube wasn't invented for at least a decade after the medieval period.

Not a YouTube channel unfortunately but there are several videos and documentaries about it.

The castle of Guedelon is exactly what you are describing.

In France a group of archeologists decided to build a full castle, from scratch pretending to be in the XIIth century.

A blacksmith is making the tools, they are chopping trees in the first forest around, extracting stones from a local carry, carrying on carts built by the Carpenter, making their own clothes ...

It's amazing !

Edit: here is an aerial picture of the castle in 2025

It's not EXACTLY the same, but this guy does a pretty good job of hitting the same vibes:

https://youtube.com/@modernknight

I can offer something in between: Clickspring. He started re-making the Antikyera (SP?) mechanism, was criticized for using modern tools for this, and then started developing and using tools basically from scratch like the people in Greece could have made and used them.

Medieval technology is vastly more complex, broader in scope, etc. compared to the Stone Age stuff on Primitive Technology. It’s actually extremely challenging to go from scratch like he does and then achieve medieval-level ironworking. He can barely make a few little iron pellets which are excessively-hard (too much carbon) and need further processing to become workable. He is a very long way from building a proper medieval smelter capable of producing pig iron or other cast iron products.

Townsends is a little bit later than medieval, but scratches that same itch. Their stuff is high quality too.

https://youtube.com/@townsends

This channel is clearly inspired by John, I think he even says so in the description. Maybe not quite medieval but definitely up the right alley Edit: I was wrong about when the medieval period started, its definitely early medieval. https://youtube.com/@gesithasgewissa

Not equivalent, but Lindybeige makes fun content about medieval times.

https://www.youtube.com/@lindybeige

Todd Cutler is a solid creator who goes over production of medieval era armour and weaponry such as longbows, warbows and the reality of armour such as plate, maille and gambesons.

Not Youtube, but check out Tudor Monastery Farm

I love that show, my son does too!