PATENT-PENDING STAINLESS STEEL LID DESIGN: Our uniquely engineered two-part lid/valve kit is the only stackable 100% medical-grade (316) stainless steel fermenting system for mason jars on the market! The cleverly designed one-way valves ("waterless airlocks") prevent oxygen and pathogens from entering your fermentation while allowing carbon dioxide to escape.</br>FERMENT LIKE A PRO: Pro bioengineers ferment exclusively with stainless steel?? why shouldn't you? Our fermenting lid kit has the smallest amount of plastic on the market! We also ditched the pool of stagnant?? pathogen-filled water sitting right over your precious ferments by eliminating the traditional water-based airlock.</br>EASIEST TO STERILIZE: Unlike prod"s that melt or rust?? our stainless steel lids?? silicone gaskets and valves are dishwasher and boil bath safe. They have simple?? smooth shapes and being mostly stainless steel the lid lacks crevices and pores that can harbor unwanted bacteria and pathogens.</br>MULTI-PURPOSE: You can ferment almost anything with our kit?? including: pickles?? kombucha tea?? kimchi?? sauerkraut?? yogurt?? kefir?? and sourdough. These lids can also be used to store coffee beans which need to off-gas after roasting.</br>We offer superb?? highly-responsive US-based customer service and back all our products with a 100% satisfaction guarantee.</br></br>Product Description</br></br><b>Trellis + Co. - Freshly Engineered Elegance</b><br>We are a family business created by a bioengineer living on a homestead in one of the remotest areas in the Lower 48. When "the store" is a 4-hour drive?? every purchase must be a robust and functional investment. Here at Trellis + Co. we design products worth investing in.<p><b>Why Mason Jars?</b><br>When not in use?? mason jars take up a lot of space so we reuse them as often as possible. We live in a small space so having a special crock or other apparatus just for fermenting seemed ridiculous and expensive! Because mason jars are so versatile?? this kit also works great for properly storing coffee beans.<p><b>Why 100% Stainless Steel?</b><br>We avoid plastics and ceramics because we <b>always</b> break them. Their porous surface can harbor bacteria more easily?? plastics allow gases to permeate across walls?? and they both often absorb smells and tastes. Stainless steel allows none of this! Pro bioengineers use 100% stainless steel?? why shouldn't you?<p><b>Patent-Pending Design</b><br>We pursued a patent on the design because?? well?? that's what engineers do! This lid took some very ti