Folinstall 1.5 Gallon Fermentation Jars Review 2025

Quick Verdict

If you have been eyeing fermentation jars for a while and want a set that removes the most common frustrations — pressure build-up, cramped openings, guessing measurements — the Folinstall 1.5 gallon fermentation jars are worth serious consideration. They are not perfect for every kitchen, and the weight of a full jar is genuinely something to plan around. But six weeks in, with three ferments under my belt, I keep reaching for them. Score: 4.2 out of 5.

What Is the Folinstall 1.5 Gallon Fermentation Jar?

The Folinstall fermentation jar is a square-shaped, wide-mouth glass mason jar designed specifically for home fermentation projects. The 1.5 gallon (roughly 5.7 litre) capacity sits in the sweet spot for most home fermenters — large enough for a solid batch of kimchi or pickles, not so big that you are committing to feeding an entire neighbourhood. It ships as a two-jar kit with three airlock valves and two silicone plugs.

The square body is the first thing you notice. Unlike the standard round mason jars that roll and wobble on fridge shelves, these sit flat and align neatly. The lid system is two-piece: an airlock valve for active fermentation (it lets CO₂ escape without letting air in), and a solid silicone plug you swap in once fermentation is done for airtight storage. The wide 4.3-inch mouth is genuinely convenient — I stopped dreading the clean-out phase, which is not something I expected to write in a review.

Key Features

• Square glass body — stable, space-efficient, fits standard fridge shelves
• Built-in airlock valve — releases CO₂ automatically, no manual burping required
• Wide 4.3-inch mouth — simplifies filling, adding ingredients, and scrubbing after use
• Dual scale markings — ml and Fl.oz printed on the jar side for accurate measuring
• Two-stage lid system — airlock valve for active ferment, silicone plug for storage
• Complete kit — 2 jars, 3 airlock valves, printed instruction manual
• BPA-free silicone components — food-safe materials throughout

Hands-On Review

I set these up on a rainy Saturday afternoon — the kind of day that makes you want to start a kimchi batch for no particular reason. The unpacking experience was straightforward. Two jars, three airlocks, a manual. I washed everything with hot water (no soap needed for fermentation gear, generally), and got my first batch of napa cabbage kimchi going within about forty minutes of opening the box.

The airlock was where this kit earned its keep. Every other jar I have used for fermentation required me to remember to "burp" it daily during the active phase — loosen the lid for a second to let gas escape. With these, the valve did it automatically. I left for a long weekend on day three of the kimchi ferment and came back to a jar with zero pressure build-up, no splattered brine on the counter, and perfectly active fermentation. That alone would have sold me.

Week two brought a sauerkraut test. I packed whole cabbage leaves in layers, which would have been a nightmare through a standard-mouth jar. The wide opening made it almost relaxing. I also used the scale markings for the salt brine calculation — 2% salt by weight, which means I needed roughly 1,140 ml of water for a 57g salt dose. The markings are printed clearly enough to read at a glance, which sounds minor but becomes essential when your hands are covered in brine.

What surprised me was the weight. An empty Folinstall jar is not light — probably around 3 pounds of glass. When full of kimchi and brine, one jar gets genuinely heavy for a standard refrigerator shelf. I moved one to the bottom shelf and left it there. On the second jar, which I used for a small kombucha SCOBY hotel, I was more careful about placement. The square shape helps with stacking, but you do feel the heft.

Clean-up was less painless than I hoped. The airlock valve disassembles into three pieces, and all of them need a small brush to get into the corners where brine dries. Fine, honestly — this is true of every fermentation valve I have used. But it is not a "rinse and done" situation. I soaked the valve parts in warm water for ten minutes before scrubbing, and that worked well.

Who Should Buy It?

The Folinstall fermentation jars are a strong fit if you are new to home fermentation and want a forgiving, all-in-one kit that handles the technical details (airlock management, seal quality) so you can focus on the recipe. The wide mouth also makes these practical for anyone who regularly works with whole or large-cut vegetables — think Korean kimchi, half-sour pickles, or big batches of fermented hot sauce.

Fermenters who value fridge organisation will appreciate the square footprint. If you have ever played Jenga with round jars in a crowded crisper drawer, you know what I mean.

Small-batch mead makers and kombucha brewers who need a reliable seal over multi-week fermentations will find the two-stage lid system useful — switch from valve to plug when you move from active ferment to storage.

Skip these if your fermentation projects are always small-batch (under 1 litre per session) — the 1.5 gallon size means you are either committing to a full jar or wasting space. Also skip if you need jars that are dishwasher-safe on the top rack — the airlock silicone parts should be hand-washed to maintain the seal over time.

Alternatives Worth Considering

If you need something smaller or prefer the classic round mason jar silhouette, the Ball 1-Gallon Clear Glass Jar is a well-established option. It lacks an airlock valve in the base lid, so you will need to buy a separate fermentation lid, but the jar itself is widely available and familiar.

For a similar square design at a comparable price point, the Masontops Fermentation Pickle Jar Set offers a 1-gallon square jar with a Pickle Pipe silicone lid. The smaller size suits single-batch sauerkraut or smaller kimchi projects better than the 1.5 gallon Folinstall.

Kombucha-specific setups like the GT Dave's 1 Gallon Kombucha Jar with its built-in spigot make sampling during fermentation easier, though you trade the square storage efficiency for a round footprint.

FAQ

Final Verdict

The Folinstall 1.5 gallon fermentation jars solved the two problems that have frustrated me most with home fermentation over the years: pressure management and usability during the fill-and-clean cycle. The airlock valve is reliable, the wide mouth is genuinely convenient, and the square body makes fridge storage far less chaotic. The weight of a full jar is the main thing to plan around, and the airlock clean-up is a minor inconvenience — but neither is a dealbreaker in my experience. For anyone serious about consistent home fermentation, this kit earns a recommendation.