I recently used a Mason jar to make & shake a homemade dressing. When I shook it, a little of the dressing came out. Has this happened to you before, and is the sealed (a cap, screw ring type )?
This is what the canning process does. I find I can get a satisfactory seal as long as the glass sealing surface and the cap are clean. Any debris and the jar won't tightly seal. Hand-tight does the job.Like bob says, give them time, or warm the glass up a bit before you put the lid on - when it cools down it will seal the cap for you.
And those caps can get really secure, I've got a few jars that became quite tough to open.
I recently used a Mason jar to make & shake a homemade dressing. When I shook it, a little of the dressing came out. Has this happened to you before, and is the sealed (a cap, screw ring type )?