Why is (or isn't) there a notch in this lid??

I try to only write blog posts when I feel there is important information to share.  Typically, when I start to see the same emailed questions repeatedly, that tells me there is some confusion out there that needs to be cleared up!  Over the last few months, I have had multiple customers email with concerns that their fermenting crock lid either did or did not have a notch in it. 

I'm not sure where people are getting their information, but there seems to be some sources out there that are arguing both sides - you absolutely must have a notch in the lid, or you absolutely do not want a notch!  The truth is, it really depends on the crock.  So today, I would like to address why some crocks have notches in their lids and some don't!

Small Crock = no notch, Large Crock = notch

In general, smaller crocks do not have notches in the lids, and you don't want them to.  Only large crocks with deep wells and heavy lids should have a notch in the lid. 

Light Weight Lids don't need a notch

Smaller crocks, with lighter weight lids and a shallower well do not need a notch in the lid.  Because the lid is lighter weight, when gases need to escape they simply push up on the lid enough for the gas to bubble out.  A heavier lid can't push up so easily, so a notch was added to allow the gas to escape. 

Shallow airlock wells don't work with notched lids

In addition, when there is a notch in the lid, the water level in the airlock well has to be kept above that notch in order to maintain the airlock.  When the well is shallower, a notch in the lid can make it very difficult to keep enough water in the well to maintain the airlock without overfilling the well so that water gets into the ferment. 

Our crocks are designed to ensure that their first priority is to be functional fermenting crocks, and sometimes that means there are different features for each one!  Our artisans have tested the features of their crocks to ensure that they only add a notch to the lid when it is needed.
 
Hopefully that helps you understand a little better why some fermenting crock lids have notches and some don't!  It's not a universal feature that should be included on every crock!