Fermentation Brine: Salt to Water Ratio for Vegetables

Using a proper fermentation brine is important for successfully fermenting vegetables. While each of my recipes has a recommended salt-to-water ratio, this post provides general information to help you calculate your own fermentation brine ratio.

I was inspired to explore brine ratios after my interview with the owner of Agrius. A precise ratio of salt by weight is how they ensure that all their ferments are safe, delicious, and shelf-stable for up to a year.

Having been fermenting for a while, I’ve seen a number of brine ratio charts and calculators. They vary from 2 to 5% salt to water ratios, depending on the type of vegetables. However, Agrius uses a MUCH simpler fermentation brine. Regardless of what they are fermenting, their salt ratio is 2.2% based on the total weight of vegetables and water.

With this ratio, they are able to pack seasonal vegetables into unsealed jars for fermenting and leave them for over a year without any concerns.

Here is how you can bring that level of precision to your homemade fermented vegetables.

Choosing a Salt to Water Ratio

Here are a few things to know when deciding what salt to water ratio to use.

• It is perfectly fine to use any salt ratio from 0% up to 5%. Anything higher than 5%, and you risk stopping the fermentation.
• Ferments with a salt ratio of less than 2% risk going off. However, if you are on a low sodium diet then it is possible to make salt-free fermented vegetables by using a good starter culture.
• If your vegetables end up tasting too salty, then you can rinse off the brine before serving them, or use them as a salty seasoning in other dishes.
• Precision is not necessary for home fermenters. Pretty much any salt ratio between 2% to 5% will result in delicious and healthy fermented vegetables. It’s fine to taste your unfermented sauerkraut or green bean pickle brine to decide how much salt you need to add.
• Not all salts weigh the same, so unless you’re making your ferment by weight, it will never be perfectly precise. And that’s okay. Your great-great-grandparents were probably fermenting based on imprecise measurements, like handfuls of salt and it usually worked out.
• The reason why many books and websites recommend a different salt to water depending on the type of vegetable is that each vegetable has its own mass and density. A whole pickling cucumber is full of water, however, shredded cabbage is much less dense.

2.2% Brine

Agrius’ salt to water ratio of 2.2% works for everything from sauerkraut to fermented pickles because it takes into account the weight of the vegetables as well as the added water.

Here’s how to use this ratio in your own home. It’s easiest if you have a digital scale, but if (like me) you don’t, then I have a chart based on jar sizes that provides a fairly good estimate.

Fermentation Brine Calculator

The easiest way to calculate the amount of salt required for your fermentation brine is to use a digital scale.

Here are the 7 steps to calculating the required salt by weight using a digital scale.

1. Weigh your jar. Write down the weight.
2. Fill the jar with your vegetables, spices, and anything else you’re going to use for the ferment. Add water, to cover.
3. Weigh the jar again.
4. Calculate the total weight of water and vegetables by subtracting the filled weight from the original weight. Alternatively, if you happen to have two jars that are the same, use an empty jar to zero your scale, then weigh the full jar.
5. Take your jar off the scale, then use the scale to weigh out 2.2% of salt by weight. Use the handy calculator below to help you calculate 2.2% of your original weight.
6. It’s fine to add the salt directly to the jar. Give it a stir to dissolve the salt.
7. Put on the lid and leave the vegetables to ferment.

If calculating 2.2% of something isn’t your strong suit, then here is a handy calculator. It’s not super fancy, just a bit of code that Brad wrote for me. I recommend using grams because they’re easier to deal with when using really small amounts.

Total weight of vegetables and liquid grams / ounces
Salt required for 2.2% brine grams / ounces

Fermentation Brine Chart

After breaking two digital scales, my sister-in-law bought me a traditional cast-iron balance scale, so I can’t use the method above. Instead, I borrowed a digital scale from a friend and calculated a rough guide of how much salt to add for common jar sizes with three types of salt: flaked pickling salt, medium-fine pink Himalayan salt, and extra fine sea salt.

Here are a few notes for anyone planning on using this brine chart:

• As it turns out, the sea salt and pickling salt, weighed the same amount. The pink Himalayan salt was a bit heavier. So I created my brine chart based on the weight of flaked pickling salt or fine sea salt.
• Depending on the type of vegetable, it may result in a slightly salty brine, because not all vegetables have the same density. However, it’s a pretty good approximation. (If you want to double-check my math, I’ve got the steps I used set out below the table).
• One last note… I personally like my ferments a little less salty than a ratio of 2.2%. So most of my quick-to-eat ferments are actually about 2% brine. However, if I want to stash something in my closet for more than a few weeks, then I always go with at least a 2.2% brine.

Jar Size	Salt
Half-pint (236 ml)	3/4 tsp
Pint (473 ml)	1 1/2 tsp
Quart (946 ml)	3 tsp
500 ml (16.9 oz)	1 5/8 tsp
1 L (33.8 oz)	3 1/8 tsp
1 1/2 L (50.7 oz)	4 3/4 tsp

How I created the chart

Here are the steps I took to figure out how much salt to include for each jar size.

1. I started by weighing how much water would approximately fit in a one-quart jar. It’s less than the expected 946 g because it’s important to leave headspace for bubbling. So it actually came out to 915 g.
2. Then I used Brad’s handy calculator to figure out how much salt was needed for 915 g. It came to a nice and even 20 g. (How lucky was that!)
3. Then I compared the weight of water to the weight of a few different types of ferments. For example, a quart of sauerkraut weighed 853g, requiring 19g of salt. A quart of beets weighed 964g so it would need 21 g of salt.
4. I’ll admit that rounding is never perfect, but 1 gram of salt is very little. So I decided that 20 g of salt would be a nice happy medium for a quart-sized jar.
5. Next, I weighed the three types of salt to figure out how much was needed for 20 g. The pickling salt and fine sea salt both needed exactly 3 tsp. The medium-fine pink Himalayan salt needed a bit more than 3 tsp.
6. Thus, for those of us who don’t have a scale at home, we can use a rough ratio of 3 tsp of salt per quart size jar. It might be a bit salty for sauerkraut (2.5% brine) and a bit less salty for pickled beets (2% brine). But on average it will be nearly just right.