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.
- Weigh your jar. Write down the weight.
- Fill the jar with your vegetables, spices, and anything else you’re going to use for the ferment. Add water, to cover.
- Weigh the jar again.
- 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.
- 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.
- It’s fine to add the salt directly to the jar. Give it a stir to dissolve the salt.
- 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 / ouncesSalt 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.
- 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.
- 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!)
- 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.
- 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.
- 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.
- 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.
tsp (t) = teaspoon
Tbsp (T) = tablespoon
do you really mean 3 tsp per quart? that would be 1 tablespoon, would it not? seems not enough.
Hi! I do mean 3 tsp (1 Tbsp) per quart. That’s not per quart of water, but rather per quart-sized jar of vegetables and water. You could use slightly more salt without stopping the fermentation, however, the resulting vegetables would be quite salty. Cheers!
Hi Emille, I like your precision and understanding, which is above the usual I find on the www. A roughly 2% solution, as you say works most the time, and by that I mean that the weight of salt is 2% the entire weight of the jar contents – veggies plus water. But I can’t get it to work for cucumber pickles, and in order to prevent the white mold that forms, I need maybe twice that concentration. I’ve seen suggestions as high as 5%. The reasons for such differences are complicated, as you indicate, and the water concentration of the veggie probably affects it. Also, different veggies will probably form different lactic acid bacteria and the time required to build up enough lactic acid varies. For instance, mustard greens and garlic take a very long time for the fermentation process.
Interestingly, some Asian recipes call for the use of starchy rice water, for instance when fermenting mustard greens. I wonder if that’s a way to compensate for the long fermentation times, assisting the bacteria. With all these things, the more experience the better, but in the main, it’s all remarkably simple, and it amazes me that Nature has provided for such simple methods that allow us to enjoy such a complex chemical factory in our bodies.
Hi Tom, That’s interesting that the 2.2% salt won’t work for cucumbers for you. It’s roughly the ratio for both of my fermented cucumber recipes. I’ve been making them for years using this ratio. They do get a white powdery dusting in the jar, which is spent yeast (in the jars that ferment for several months). Or if I do open-air fermenting, then I have to remove the scum.
I can imagine the starchy rice water might help provide the sugars needed to kickstart fermentation? Hum, I haven’t tried it though. Sometimes I add a wee bit of vinegar to speed up the acidification of the ferment, which can help the acid-loving Lacto-bacteria.
Cheers!
Hi Emillie!
I just discovered your blog and I love it! Lots of great info.
I am in Costa Rica, so fermenting at 18C is impossible here. I have heard that for hotter weather, adding more salt is best. Is that true? Any suggestions on this?
Thank you!!!
To be honest, I haven’t looked into it in detail (future blog post maybe?). In general, vegetables will ferment faster in warm weather. So I usually only ferment things for about 1 week in the summer. If you want to use fermentation for long-term storage, then increasing the salt is probably a good idea. You can easily double the amount provided in the blog post and it will only be 4.4%. However, that would be quite salty. So maybe just add a bit extra salt? There’s really a lot of leeway between 2% and 5% brine ratios. Good luck!
Great post – salt has always been a challenge for me! I have a question about this line:
“…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…”
Does this mean in the fridge or on a shelf?
Thank you!
On a shelf… ๐ The first time you do it is exciting… but usually if something is going to go moldy it does it in 1 week… if not, then it can last for months. Cheers!