Fermented Peppers, Green Tomatoes, Okra and Zucchini

Bell peppers, jalapeños, green tomatoes, okra and zucchini ferment in the same 5 percent brine in the calculator: 5 g of salt per 100 g of water. For 2 lb (0.91 kg) of vegetables in 1 quart (0.95 L) of water that is 47.3 g (1.7 oz) of salt, which is 3/8 cup of Diamond Crystal kosher, 3 1/2 Tbsp of Morton kosher or 2 1/2 Tbsp of table salt. The calculator returns identical numbers for all five, so they share one set of tables below. Sliced or shredded zucchini can also be salted dry at 2.5 percent of its weight, which is 22.7 g for 2 lb (0.91 kg).

The time is 21 to 28 days at 68 to 72°F (20 to 22°C) and 35 to 42 days at 60 to 67°F (16 to 19°C). These are general fermented-vegetable times, not written for any of these five, and the recipes for each finish much sooner. The sections and the time section explain the gap. The okra section rests on one recipe.

The vegetables side by side

Salt percentage

The percentage is grams of salt per 100 grams of water, not of the vegetables; the dry-salt percentage is per 100 grams of zucchini, with no water added. The brine percentages guide explains the difference.

Firm brine, 5 percent. This is the default. Illinois Extension gives 5 percent for whole and large pieces of vegetables, which is what this guide covers. K-State Extension names peppers at about 2 teaspoons of salt per cup of water, which is about 5.1 percent.

Standard brine, 3 percent. Illinois Extension calls a 3 percent brine generally safe for shredded vegetables, so 3 percent is a general figure for these vegetables and not a pepper, tomato, okra or zucchini figure.

Dry salt, 2.5 percent, zucchini only. Sliced or shredded zucchini can be salted at 2.5 percent of its weight, inside the 1.5 to 3 percent Mother Earth News calls typical. The zucchini section gives the sources.

The sources do not agree on one number, and each section lists what its recipes use.

Salt and water by weight

Weigh the vegetables after trimming and cutting, before adding brine. K-State Extension uses about 1 lb of vegetables and 2 cups of brine per 1-quart jar, which is the calculator's 0.5 quart of water per pound. The calculator accepts 0.5 lb (0.23 kg) to 10 lb (4.54 kg) of these vegetables.

Firm brine, 5 percent (default)

Standard brine, 3 percent, for shredded vegetables

Sliced or shredded zucchini, dry-salted, 2.5 percent

The calculator uses 2.8 g per teaspoon for Diamond Crystal, 4.8 g for Morton kosher and 6 g for table salt. The guide to kosher and table salt in brines covers why the volumes differ.

Sources differ on water. Illinois Extension's fermentation handout says filtered water or spring water is preferred and not to use distilled water. University of Minnesota Extension says to use soft or distilled water because hard-water minerals can discolor produce or change its texture. The water shown in the tables is a default; use enough to cover the vegetables completely, enter your own amount in the calculator and the salt follows it.

How to ferment these vegetables

The method is the same for every vegetable here, and the how to ferment vegetables guide walks through it. Weigh the vegetables after trimming and cutting, dissolve the salt in the water, pack the vegetables and cover them with the brine, and weigh them down so they stay under it. University of Minnesota Extension keeps 1 to 2 inches of brine above the produce, and says fermented produce can be kept refrigerated for up to 9 months once it tastes right. Each vegetable's section below lists what differs.

Bell peppers

That time is general guidance for fermented vegetables, not a bell pepper source. The one bell pepper recipe the calculator checked is a mixed-vegetable recipe with a much shorter time, and that gap is explained below.

What the recipes say. The calculator checked these sources for bell peppers. Their salt and time are listed as the sources give them.

Cut and weight. Weigh the peppers after trimming and cutting, before adding brine. The times apply to bell peppers that are cored and cut into chunks or strips. K-State Extension uses about 1 pound of vegetables and 2 cups of brine per 1-quart jar, the calculator's 0.5 quart of water per pound.

Salt. The 5% brine is the default because K-State Extension names peppers at that strength. Its standard brine is 1 teaspoon of salt per cup of water, and it gives high-water vegetables such as cucumbers and peppers 2 teaspoons per cup, about 5.1%. Illinois Extension calls a 3% brine generally safe for shredded vegetables and says whole and large pieces should use a 5% brine, so the 3% strength is a general figure that does not name peppers and the 5% strength is the one to use for whole or large pieces.

The other sources vary. University of Minnesota Extension gives 1 to 3 tablespoons of salt per quart of water for wet-brined vegetables in general and lists peppers for sauce as one example, not as a pepper-specific amount. That works out to about 1.9% to 5.7%, and those percentages hold only if the salt is table salt at 6 g per teaspoon. The Kitchn recipe uses 3 tablespoons of salt in 1 quart of water, about 2.7% to 5.7% depending on the salt.

Time. The Kitchn recipe ferments red bell pepper with cauliflower and carrot at room temperature, gives no temperature range, and reports its own batch was tangy after three days. The calculator uses the longer extension minimum instead.

Steps that differ for bell peppers. The shared steps are in the method section.

• Pack the jar. Pack the peppers into a clean jar and pour the brine over them, leaving at least 1 inch of headspace as the Kitchn does.
• Keep them under the brine. The Kitchn suggests weighing them down with a small jar or bowl and says this helps prevent mold.

Mold or yeasty scum. The Kitchn says to skim off any mold or yeasty scum.

Mushy peppers. Wild Fermentation says salt hardens pectins, which makes vegetables crunchier, and that salt-free ferments often end up with mushy textures. It does not name bell peppers.

Jalapeños

That time is general guidance for fermented vegetables, not a jalapeño source, and the jalapeño recipe the calculator checked gives a much shorter one. Both are explained below.

What the recipes say. The calculator checked these sources for jalapeños. Their salt and time are listed as the sources give them.

Cut and weight. Weigh the peppers after trimming and cutting, before adding brine. The times apply to whole or 1/4 inch sliced jalapeños with the stems removed. K-State Extension uses about 1 pound of vegetables and 2 cups of brine per 1-quart jar, the calculator's 0.5 quart per pound.

Salt. The 5% brine is the default because K-State Extension names peppers at that strength: about 2 teaspoons of salt per cup of water, which it gives for high-water vegetables such as cucumbers and peppers. Illinois Extension calls a 3% brine generally safe for shredded vegetables and says whole and large pieces should use a 5% brine, so the 3% strength is a general figure, not a pepper figure, and the 5% strength is the one to use for whole or large pieces.

The sources for peppers vary. University of Minnesota Extension gives 1 to 3 tablespoons of salt per quart of water for wet-brined vegetables in general and lists peppers for sauce as one example, not as a pepper-specific amount. That works out to about 1.9% to 5.7%, and those percentages hold only if the salt is table salt at 6 g per teaspoon. The Hobby Farms jalapeño recipe is 2 teaspoons of coarse kosher salt in 1 cup of water, which is about 2.4% to 4.1% depending on the salt.

Time. Hobby Farms ferments sliced jalapeños at 60 to 75°F (16 to 24°C) for five days and says to taste, then add a day or two if they still taste mostly raw. The calculator uses the longer extension minimum.

Steps that differ for jalapeños. The shared steps are in the method section.

• Prepare the peppers. Trim and cut them, then weigh them. Hobby Farms slices them 1/4 inch thick; the calculator's times also cover whole peppers with the stems removed.
• Keep them under the brine. Peppers float. Hobby Farms uses a small fermentation weight and pushes floating pieces back under the brine each day.
• Refrigerate. Move the jar to the refrigerator with its brine. Hobby Farms recommends eating the peppers within six months.

Cloudy brine and white sediment. Hobby Farms says both are normal for a jalapeño ferment. Wild Fermentation says a white film on the surface is common and can be scraped off, while the surface growth note in the safety section shows that other sources word this differently.

Green tomatoes

That time is general guidance for fermented vegetables, not a green tomato source. The recipes the calculator checked give 6 days to 20 days, and the reasons for the gap are below.

What the recipes say. The calculator checked these sources for green tomatoes. Their salt and time are listed as the sources give them.

Cut and weight. Weigh the tomatoes before adding brine. The times apply to whole small green tomatoes or green cherry tomatoes.

Salt. The 5% brine is the default. Illinois Extension gives 5% for whole and large pieces and calls a 3% brine generally safe for shredded vegetables. It does not name green tomatoes.

The recipes fall on both sides of 5%. The Kitchn's Bar Tartine brine is 1 tablespoon of kosher salt per cup of water, about 3.6% with Diamond Crystal and 6.1% with Morton. The Mother Earth News basic brine is 1 1/2 teaspoons of unrefined salt per cup, about 3.8% if the salt weighs 6 g per teaspoon.

Time. The recipes are shorter. The Kitchn ferments 6 days to 2 weeks until the vegetables taste sour, stored at 50 to 60 degrees (the page gives no unit), then refrigerates them for one more week before serving. Mother Earth News ferments for 10 to 20 days after a salt pressing of 8 hours to overnight, and gives no temperature. The calculator uses the longer extension minimum.

Steps that differ for green tomatoes. The shared steps are in the method section.

• Rinse and weigh. Rinse the tomatoes and weigh them. Mother Earth News cuts a cross in each from the stem end, stopping before the bottom.
• Make the brine. Weigh the water and salt, and dissolve the salt completely. Both recipes use unchlorinated or filtered water.
• Pack the jar. The Kitchn adds spices and herbs, then the vegetables, then pours the brine over them just to cover.
• Keep them under the brine. The Kitchn weighs the vegetables down with a plate and weights.
• Taste and refrigerate. Mother Earth News says the tomatoes are ready when the taste and smell are pleasingly acidic and keeps them 6 to 8 months in the refrigerator.

A cool room. The Kitchn's 50 to 60 degrees, with no unit given, would be below the band in the temperature warning if it means Fahrenheit. University of Minnesota Extension says temperatures below 60°F (16°C) inhibit fermentation, and the calculator shows no time below that.

Cloudy brine and muted color. Mother Earth News lists muted color and cloudy brine as signs the ferment is ready.

Mold. The Kitchn says to skim mold and keep the vegetables submerged. The surface growth note in the safety section shows that other sources word this differently.

Okra

This section rests on thin evidence: only one okra recipe was found, and the time is general guidance for fermented vegetables.

What the recipes say. The calculator checked these sources for okra. Their salt and time are listed as the sources give them.

Cut and weight. Weigh the okra after trimming, before adding brine. The times apply to whole small, tender pods.

Salt. The 5% default is close to the one okra recipe found, Sandor Katz's fermented okra in Mother Earth News, which uses 1 1/2 tablespoons of sea salt in 2 cups of water. That is 3 tablespoons per quart, which Wild Fermentation puts at about 5.4%. 5% is also the strength Illinois Extension gives for whole and large pieces, but it does not name okra.

Illinois Extension calls a 3% brine generally safe for shredded vegetables, so the 3% strength is a general figure. Wild Fermentation's simplified guide lists okra among whole vegetables to submerge in brine but gives no percentage.

Time. The okra recipe is much shorter: Mother Earth News says 3 to 4 days, then taste every day or two, for 3 days to 2 weeks in total. The calculator uses the longer extension minimum.

Steps that differ for okra. The shared steps are in the method section.

• Choose and trim the pods. The recipe calls for small, tender okra with damaged spots trimmed away. Weigh the pods.
• Keep them submerged. If pods float, the recipe cuts the top off a plastic container slightly wider than the jar's mouth and pushes it in to hold the okra under the brine.
• Ferment and taste. Keep the jar at 68 to 72°F (20 to 22°C). The recipe says to start tasting after 3 or 4 days and then check every day or two.
• Refrigerate once the okra softens or reaches the sourness you want, as the recipe says.

Slimy texture. Mother Earth News says whole pods keep most of their sliminess contained and that chopping spreads it. The safety warnings in this guide say to discard a ferment that is slimy or smells spoiled.

White film on the surface. The recipe says to skim off any white scum.

Zucchini

That time is general guidance, not a zucchini source, and the recipe the calculator checked describes a shorter ferment.

What the recipes say. The calculator checked these sources for zucchini. Their salt and time are listed as the sources give them.

Cut and weight. Weigh the zucchini after trimming and cutting. The times apply to small zucchini (brine) and sliced or shredded zucchini (dry salt).

Salt. The 5% brine is the default. Illinois Extension gives 5% for whole and large pieces and calls a 3% brine generally safe for shredded vegetables. It does not name zucchini. The Mother Earth News universal pickle recipe, which lists small zucchini, uses 6 tablespoons of sea salt in 2 quarts of water, about 3.4% to 3.7% of the water weight. The same page gives a rough guideline of 5% salt by weight.

For dry salt, a second Mother Earth News article says to use no more than 5% of the vegetable weight and that 1.5% to 3% is often enough. The calculator's dry-salt strength is 2.5%, inside that range.

Time. The Mother Earth News universal pickle recipe lists small zucchini. At about 70°F (21°C) the pickles are half-sour in about a week and fully sour in about 2 weeks. At about 80°F (27°C) the process might take about a week, and in a cool cellar 3 weeks or more. The calculator uses the longer extension minimum.

Steps that differ for zucchini. The shared steps are in the method section.

• Trim and cut. The Mother Earth News universal pickle recipe says to trim the blossom end of cucumbers and squash to remove enzymes that can soften the pickle. Cut spears or chunks, or ferment small zucchini whole, and weigh them.
• Dry-salt style. Toss the sliced or shredded zucchini with the salt and press it until liquid pools.

Mushy zucchini. Mother Earth News says large zucchinis break down and become mushy. Wild Fermentation adds that salt-free ferments often end up with mushy textures.

Surface film. Mother Earth News says a thin yeast film and tiny mold specks are normal and should be skimmed daily.

Dry-salted zucchini that stays dry. Mother Earth News says to let it sit a few more hours. Illinois Extension says to make extra brine of 1 quart of water and 1 1/2 tablespoons of salt if dry-salted vegetables release too little liquid.

How long they take

The calculator shows 21 to 28 days at 68 to 72°F (20 to 22°C) and 35 to 42 days at 60 to 67°F (16 to 19°C) for every vegetable in this guide. University of Minnesota Extension and Illinois Extension give 3 to 4 weeks at 68 to 72°F (20 to 22°C) for fermenting produce in general, and the calculator uses the longer minimum. Neither page gives a time written for these vegetables. The 60 to 67°F row is an inference from University of Minnesota Extension (5 to 6 weeks below 68°F, and fermentation inhibited below 60°F) and Illinois Extension (six weeks or longer if the temperature is too low).

Recipes finish sooner, and they were written for one vegetable and a stated cut. Bell peppers in a mixed ferment are tangy in 3 days (The Kitchn), sliced jalapeños take 5 days (Hobby Farms), green tomatoes take 6 days to 20 days across three recipes, okra takes 3 days to 2 weeks (Mother Earth News), and small zucchini are half-sour in about a week and fully sour in about two at around 70°F (21°C). Okra is the case where the calculator's window is least reliable, because pods soften and then turn mushy the longer they ferment. The calculator does not use these times, and a recipe's time is not a food safety limit: a ferment is ready when the pH is 4.60 or lower and bubbling has stopped (University of Minnesota Extension), which a taste test cannot tell you.

Safety

The National Center for Home Food Preservation says salt favors the growth of desirable bacteria while inhibiting the growth of others, and that a minimum, uniform level of acid is needed to prevent botulinum bacteria from growing, so the acid that fermentation produces matters for safety as well as taste. University of Minnesota Extension explains that lactic acid bacteria convert sugars into lactic acid and release carbon dioxide. The brine food safety guide collects the limits that apply to every brine.

The limits on salt type, container materials, surface growth and sodium are the same for every ferment, and the how to ferment vegetables guide lists them with their sources. UC Davis says the pH must be below 4.6 to prevent botulism and that its overview of the process is not a validated process.

Problems and what causes them

Illinois Extension says oxygen exposure lets mold and yeast grow, and that salt keeps vegetables crisp by firming pectin and slowing pectinase, the enzyme that causes mushiness. Keeping the vegetables under the brine and not cutting the salt address both.

Related guides

How to ferment vegetables covers the method, and the fermentation salt percentage chart compares strengths across vegetables. Fermented cucumber pickles are another whole-vegetable ferment, and vegetable brine recipes puts the brine strengths side by side. The fermented carrots, beets, radishes, turnips and garlic guide and the fermented cauliflower, green beans, asparagus and Brussels sprouts guide cover the other vegetables the calculator handles.