The Perfect Lacto Fermentation Salt Ratio
Determining the perfect lacto fermentation salt ratio isn’t about how salty or not salty you like your fermented vegetables. We have to focus on how salty certain microbes like it.
Particular concentrations of salt pave the way for creating a happy home for lactic acid-producing bacteria. Mainly, Leuconostoc and Lactobacillus bacteria thrive in fermented vegetables.
All the microbes needed for the fermentation process are already present on your vegetables, even after you wash them. Once you provide the proper salt concentration, bacterial succession can occur, and lactic acid can be adequately produced.
How to Measure the Perfect Fermenting Brine Ratio
To use a precise and accurate salt concentration, you must use units of mass to measure your salt.
There are two mathematical ways to create an exact percent salt concentration, and the desired salt concentration varies by type of vegetable.
Recommended salt concentrations are included in our blog, The Complete Guide to Safely Using Salt in Vegetable Fermentation.
Let’s look at 2.5% as an example
To create an exact 2.5% total salt concentration, place a bowl on a scale and tare/zero the scale. Add 2.5 grams of salt to the bowl, then add your produce and any water into that same bowl up to 100 grams. That’s a 2.5% total salt concentration.
What we do is slightly different and easily applied to variable amounts.
How We Measure the Perfect Fermenting Brine Ratio
We weigh all our produce and water, multiply that weight by 2.5%, and add the number we get in grams of salt.
This results in an approximate 2.5% salt concentration that is perfectly safe and optimal for fermentation. This mathematical method can also work with any total salt concentration.
Lacto fermentation salt ratio example:
If we have 100 grams of produce and water, we multiply by 2.5%. 100 x 0.025 = 2.5. So we add 2.5 grams of salt, which gives us a total salt concentration of 2.44%.
To calculate the total percent salt concentration of the entire mixture, divide the grams of salt by the total grams of the whole mixture: 2.5 grams of salt / 102.5 grams (of salt + water + produce) = 0.02439.
Move the decimal to make it a percent, and you get 2.44%
And guess what? With this method, we end up with 2.44% salt, no matter the weight of vegetables or water. If we add 2.5% salt, the resulting total salt concentration will always be 2.44%
lacto fermentation salt ratio example 2:
If we have 756 grams of cabbage and water, we multiply that by 2.5%, which equals 18.9 grams of salt.
18.9 / (756+18.9) = 0.02439
Yep. That’s 2.44%
You will only get a consistent salt concentration throughout different fermentation batches by weighing the produce and water, doing math, and then weighing out your salt.
Lacto Fermentation Salt Ratio
You might be wondering why we use the weight of water and the weight of vegetables to determine the perfect salt ratio for fermentation. All vegetables are at least 93-98% water, so you must account for the water inside the vegetables. Because of osmosis and concentration gradients, the total salt concentration includes the water in the vegetables.
Between batches and throughout the seasons, the weight of the vegetables you are fermenting will vary, because the water density of the vegetables will vary. For instance, a summer cabbage is much lighter than a winter cabbage because summer cabbages aren’t as water-dense.
Measuring Salt in Vegetable Fermentation
You may also wonder why we should use weight to measure ingredients. Simply put, the same volume of different salts contains different amounts of NaCl.
Depending on what brand, style, and type of salt you are using, the amount of NaCl in a volume measurement, such as a tablespoon, varies greatly.
Unrefined sea salt can be found in many different “grains,” such as flake, large grain, small grain, etc. A teaspoon of flake salt has a mass of about 1 gram, and a teaspoon of small-grain Himalayan salt has a mass of about 3 grams.
Adding a teaspoon of flake salt to 100 grams of vegetables and water gives you a 0.99% salt concentration. Adding a teaspoon of Himalayan salt to 100 grams of vegetables and water gives you a 2.9% salt concentration. That’s a huge difference, and the 0.99% salt concentration is completely unsafe and probably won’t select for probiotic microbes.
Other Fermentation Factors
Accurate salt concentration, adequate time for fermentation, and proper temperature are necessary for a healthy population of microbes to develop in vegetable fermentation.
The temperature for vegetable fermentation should be between 70 and 80 degrees F. However, anywhere between 60 and 90° F is acceptable. The cooler the temperature, the slower the fermentation, and the hotter the temperature, the faster.
Once the temperature is established, the two main factors that need to be tailored to the microbes are salt concentration and the length of time for the fermentation.
Suppose all of these things are accounted for appropriately. In that case, the pH of the fermentation will drop, lactic acid will build up, the microbial population will consist only of probiotic bacteria, and the vegetable matter will be preserved.
Get Started Fermenting At Home
- How to Make Old Fashioned Sauerkraut with Caraway Seeds
- Homemade Kimchi Inspired Spicy Sauerkraut Recipe
- Pepper Fermentation Recipe: Learn How to Ferment Any Type of Pepper
References:
Salt Reduction in Vegetable Fermentation: Reality or Desire?
Effects of salt concentration on Chinese sauerkraut fermentation
Survival of Escherichia coli O157:H7 in Cucumber Fermentation Brines
Frias, Juana & Martinez-Villaluenga, Cristina & Peñas, Elena. (2016). Fermented Foods in Health and Disease Prevention.
How about measurements in terms normal people can understand.
“normal” people are perfectly capable of using a kitchen scale to measure ingredients. It’s not difficult.
Again, so grateful for the attention and intention in these blogs. BIG gratitude!!!
I am curious about using water kefir (grains or solution) to ferment vegetables. Is this possible? If possible, how would you think about that? Or is this completely nonsensical from a microbiology standpoint?
I found only a little on the internet…. doesn’t seem to be a lot out there. Would love to hear your thoughts…
Thank you for this clear explanation of salt, percentages, salinity etc. I appreciate the science behind everything and like to try and understand it. I loved my microbiology class before nursing school- I should have studied it! What you do fascinates me as I love food, the history and science of it and microbiology. How lucky for you to have found such an interesting career!
I’ve got a few ferments going with mostly peppers and just a little garlic and they are all done at 4% salinity based on the weight of the water and vegetables combined. I’m worried to maybe this is too much salt and that the fermentation won’t start. Am I okay and it’s just going to take longer? If not should I dilute the brine by pouring some out and adding back distilled water? Advice from pepper groups is all over the map and more anecdotal than scientific. What would be the ideal percentage for lacto fermenting chili peppers? Thanks!
Peppers are good anywhere between 3% and 6% total salt. So they should be great. You should see them bubbling in the first 3-5 days of fermentation. If the peppers are extremely high on the scoville chart (like ghost peppers, Carolina reaper etc.) very high capsaicin inhibits fermentation. I teach pepper fermentation in this recipe Pepper Fermentation Recipe: Learn How to Ferment Any Type of Pepper
With a 2.5% brine (based on veg + water weight), after 10 days I get a pH of 5 to 5.2 (carrots, cucumbers…). Before eating, I check the pH, and I have to add more salt till I get a 4.6.
No mold, no yeast, but still at 5.2 pH.
Any ideas? Is it safe to eat it at 5.2 pH?
Do you check the pH?
I’m not sure what you’re explaining here. You don’t add more salt to make it acidic. Once you start the fermented vegetables they should get bubbly and start getting more acidic within 2-3 days. I do not lacto ferment carrots, because they don’t ferment well.
It sounds like you might not be measuring your salt correctly. 5.2 is not a safe pH.
I always check pH, with a calibrated pH meter when testing and writing my blog recipes.
Hola Kaitlynn, mi nombre es Adriana y te sigo desde hace mucho tiempo. Has inspirado mi trabajo y ahora tengo un proyecto de fermentos. Estoy en Merida Yucatan en Mexico. Quiero hacerte dos preguntas:
1.- la temperatura aqui es alta y en ocaciones la fermentación es muy rapida y pronto dejan de estar crujientes los vegetales. Sabes si hay alguna hoja o semilla que le pueda añadir para que lo conserve crujiente?
2.- me inspiraste y compré un barril de 100 kilos de roble acá en mexico pero pronto dejo de funcionar. Es posible me puedas compartir la información de donde puedo adquirir como los que ustedes usaban para traer yo a mexico?
Bendigo y Agradezco tu enseñanza y el amor compartido por las bacterias y sus divinas consecuencias
I love all your interesting ferments. I believe i am missing something in this post. You say the combination of vegetable and water to 100 grams.
What is the ratio for them?
You could have 90 grams water and 10 grams veg or visa versa. Producing 2 very different results.
What am I missing? Thanks
I want this blog to focus specifically on calculating how much salt to use, so I did not include information on the other nuances of developing a fermentation recipe from scratch.
The calculation amounts I presented here are only mathematical examples of determining salt. Generally The ratio of vegetables to water shouldn’t fall below 50:50. It’s understood that you fill the vessel with vegetables and then top with water to determine the combined weight of vegetables and water.
Thanks for this article and formulas. I have what I hope is a simple and not a silly question. Do you add the salt to the container with the veggies and water after weighing, as opposed to dissolving the salt in just the water? I ask, because some recipes I have seen say to dissolve X amount of salt into X amount of water and then add to jar.
Thanks!
not a silly question! Either way works, as long as the amount of salt you are adding is calculated with the weight of water and vegetables.
Great article/blog. I appreciate the scientific weight-based approach you use. I find it really helpful to use two-pint (1000ml) mason jars as my standard fermentation vessels. We know when full the contents will weigh very close to 1000g, and require a “standard dose” of 25g of salt per jar. Easy-peasy!
love this!
Finally! An authoritative and informative treatment of the ins and outs of fermented veggies. Most of what’s available on the subject is vague and incomplete. Thank you, thank you, thank you.
Hi. I am bewildered… When adding vegetables and water to the bowl on the scale to determine the amount of salt needed, how do I know how much water should be in the bowl? The amount of water that will fit in a jar in which I have already stuffed the vegetables, feasibly is way less water than the amount I might put in the bowl. How do I calculate that?
All the recipes on my website here already have the ideal amounts of water, vegetables and salt you need to use listed for you. If you are interested in creating your own recipes and learning exactly how I formulate recipes from scratch, I teach that in my online course. https://fermentation.school
I just started teetering in salt fermentation last winter. I made several small batches of Kraut. The first 4 batches turned out outstanding. The last 4 batches I lost two. I was just estimating the amount of salt to use instead of weighing. I am going to look into acquiring a digital scale this Fall.
yes! a kitchen scale is the best tool for consistent results!
I’m wondering – do you think I could use your garlic recipe for garlic scapes? I’m trying to fit them into one of your categories, and for the life of me, I can’ recall if they sprout from a bloom or not!
yes! You can also use my leek tops recipe
Amazing – thank you – I’m so eager for spring now! We have friends with an organic farm and they always have scapes – I’ve done a sort of scape pesto, and I would make a garlic scape / Parmesan sourdough loaf, but I find myself running out of ideas.