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Fermentation Weights: Keeping Ferments Below the Brine

It is fascinating how little is needed for lacto-fermentation. Under the right conditions, the variables of time, salt and liquid can both preserve and transform a simple food into something downright delicious and nutritious. Essentially, 2 simple rules need to be followed: blocking oxygen from the fermentation container and keeping the fermenting food below the brine.


The brine (saltwater solution) combined with the lack of oxygen creates an acidic environment within the fermentation container. While ideal for the beneficial lactobacillus bacteria responsible for the fermentation process, it is inhospitable for pathogens that could ruin the ferment and possibly make us ill. As long as the salt content is correct, the submerged food is safe and sound under the brine. In some cases, the fermenting food is so tightly packed in the container that it naturally stays put and under the brine. However, not all food behaves the same, and there are often stubborn pieces that float to the surface, escaping the safety blanket of the brine.top view of jar filled with brine with a little bit of space left at the top

There are a variety of methods and products that can be used as fermentation weights. Please note although you can be creative using items in your home, it is important that they are properly sanitized and food grade. I will share my preferred method and a few commercial options.


This is my preferred method for all my ferments. I learned this easy method from the great book, Fermented Vegetables by Christopher Shockey Kirsten K Shockey.

First, cover the fermented food using a piece of parchment paper (some people prefer using a cabbage leaf or piece of vegetable cut to size). Next place a freezer bag or sturdy food grade bag into the jar. Fill bag with brine (in the rare case that the bag ruptures, the brine in the container will not be diluted.)ziplock-wieightLid the jar. The water will act as a weight to keep the food submerged during the fermentation period.ziplock-weight-fido

For larger ferments, I use multiple brine-filled ziplock bags to act as weights.


use a smaller glass jar as a weight
use a smaller glass jar as a weight

A smaller jar can be inserted into the mouth of a larger jar and fill with pie weights, beans or water. img_1475This method is more suitable for smaller fermentation projects.  Since the inserted jar weight takes up space within the fermentation container, you are not able to fill the container to capacity with the ferment. img_1453-2

COMMERCIAL FERMENTATION WEIGHTSmason-jar-lifestyle-glass-fermentation-weights-wide-mouth-amazonfermentation weight

These are weights made of food-grade material specifically designed to fit into wide-mouth jars and fermentation crocks. They are excellent, effective tools as long as you don’t have too many ferments on the go (they can be pricey).

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