Perpetual home brew

Wild Peel Tonic

A fizzy, tart electrolyte drink for training. Made from black tea, cabbage brine and whatever fruit peels you have, it runs in one 5-liter jar and gives you a liter a day.

4 Lbrewing in the 5 L jar
1 L/dayharvest and feed back
~600 mgsodium per liter
Pinkon the red-cabbage test before drinking
Why brew your own

A sports drink with live cultures

Store sports drinks replace the salt you lose in sweat, mostly with sugar and flavoring. This tonic replaces the same salt, adds live lactic-acid bacteria and costs about as much as a cup of tea.

More sodium, less sugar

Sweat is mostly salt and water. The tonic has about 600 mg sodium per liter, more than most store drinks. The culture eats most of the 12 g of sugar per liter, so what's left is tart, not syrupy.

Live cultures

The sauerkraut brine brings lactic-acid bacteria, the same family found in yogurt and kefir. In a 2021 Stanford study, people who ate more fermented foods had a more diverse gut microbiome and lower inflammation markers.

You control every ingredient

Nothing goes in except tea, sugar, salt, vinegar and fruit. No dyes or sweeteners. Change the salt for hot days or the caffeine for evening sessions.

Cheap, and it uses scraps

A liter costs about 20–30 cents in tea bags, sugar, salt and vinegar. The flavor comes from peels you'd otherwise throw away.

Per literWild Peel TonicTypical store sports drinkWater
Sodium~600 mg~450 mgalmost none
Sugarunder 12 g~55–60 g0 g
Live culturesYesNoNo
FizzNaturalUsually flatNone
Cost~$0.25~$2–4~$0

It's a home ferment, so it varies from batch to batch and the numbers here are estimates. For sessions longer than 90 minutes you also need carbs, so pair it with fruit or the Recovery Lassi.

Compared

Kombucha or tonic?

Both are fermented tea, but they use different cultures and suit different jobs.

KombuchaWild Peel Tonic
CultureA SCOBY: yeast plus acetic-acid bacteria. Strains vary, and few are studied as probiotics.Lactic-acid bacteria from sauerkraut, such as Lactobacillus plantarum, plus wild yeast from the peels
Sugar to brew50–100 g/L~12 g/L
What makes it acidicThe culture turns sugar into acid over 7–14 daysVinegar and brine from day one
Sugar left in the glassOften 20–50 g/LUnder 12 g/L
SodiumAlmost none~600 mg/L
AlcoholHomemade often 0.5–2% or moreUsually under ~1%
Human evidenceThin. Mostly lab and animal studies, plus one small 2023 pilot on blood sugar in type 2 diabetes.None for this exact drink. Fermented vegetables in general have some support.
Time to first glass1–2 weeks2–4 days
Training

Tonic

It has the salt you lose in sweat and little sugar. Kombucha doesn't replace sweat losses.

General health

About even

Neither is proven. Claims that kombucha "detoxes" your body have no evidence behind them.

Probiotics

Kefir beats both

Grain kefir carries far more strains, in much higher numbers, and has the most human research.

The Stanford result came from eating a variety of fermented foods, not any single one. Drinking the tonic around workouts, having kefir daily and eating the sauerkraut covers more than switching to one drink. If you enjoy kombucha, keep it as a treat.

Compared

Tonic or a sports drink?

The tonic holds up well against store sports drinks. Their real advantage is carbs for long, hard sessions, which is what they were designed for.

Per liter, approx.SugarSodiumPotassiumpH
Wild Peel Tonicunder 12 g~600 mglow~3.5–4
Gatorade~58 g~450 mg~130 mg~3.0
Gatorade Zero0 g~450 mg~130 mg~3.0
Powerade~57 g~420 mg~100 mg~2.8
Gatorlyte~20 g~830 mg~590 mg~3
BodyArmor~75 g~40 mg~1,000 mg~3
Liquid I.V. (1 stick in 500 mL)~22 g~1,000 mg~740 mg~3
LMNT (1 stick in 1 L)0 g1,000 mg200 mg~3–4
Pedialyte~25 g~1,000 mg~780 mg~4

Rounded from US labels. Formulas differ by country and change over time.

Tonic wins
  • More sodium and about 80% less sugar than regular Gatorade or Powerade
  • Gentler on teeth. Most sports drinks use citric acid at pH ~3.
  • Live cultures, no dyes or sweeteners, and a fraction of the cost
Sports drinks win
  • Carbs for long sessions. Past 60–90 minutes, 30–60 g of carbs per hour helps performance, and regular Gatorade supplies that.
  • Potassium. Gatorlyte, Liquid I.V. and Pedialyte have much more. Sweat has far less potassium than sodium, and the coconut-water swap closes most of the gap.
  • Consistency. Every bottle is identical.
SituationDrink
Under an hour, or easy trainingTonic or plain water. You don't need the sugar.
1–2 hours, hard effortTonic with 2 tbsp sugar per liter, plus fruit or dates
Very long or hot, or salt stains on your clothesTonic with ½ tsp salt per liter, plus carbs
Sick with vomiting or diarrheaPedialyte. Don't treat illness with a home ferment.

The closest match to the tonic is Gatorlyte, with moderate sugar and higher sodium. The tonic has less potassium.

Equipment

What you need

Brewing

  • 5 L protein-powder jar, washed well. Replace it once the inside is scratched or cloudy.
  • Fine strainer and a funnel
  • Long spoon or tongs used only for the brew
  • Small pot or kettle for the tea concentrate

Bottling

  • Plastic soda bottles, 500 mL–1 L. Bottles made for fizzy drinks handle pressure better than thin water bottles.
  • A small jar of red-cabbage test liquid (see pH test)
Day 0 · once

Starter batch (4 liters)

3.5 Lwater
7 bagsblack tea
4 tbspwhite sugar (about 50 g)
500 mLlive cabbage brine, from homemade sauerkraut or refrigerated unpasteurized sauerkraut. Shelf-stable jars are pasteurized, so the bacteria in them are dead.
4 tbspsugarcane vinegar, 4–5% acidity (¼ cup)
1 setpeels from a flavor combo
No sauerkraut brine? Buy refrigerated unpasteurized sauerkraut, or make your own. The quick cabbage juice is ready in 3–5 days.

No extra salt in the starter. The brine provides about 1 g of sodium per liter at the start, and this settles to about 600 mg once the daily feeds take over.

  1. Make a concentrate. Steep the tea bags in 1 L of boiling water for 5–10 minutes. Remove the bags and stir in the sugar until it dissolves.
  2. Cool it. Add 2.5 L of cold water. Check the temperature with a clean finger. It should feel cool or barely lukewarm, below 30 °C, because heat kills the culture.
  3. Start the culture. Pour everything into the jar: tea, brine, vinegar and peels.
  4. Loose lid. Screw the lid on, then back it off a quarter turn so gas can escape. Keep it out of the sun, ideally at 20–26 °C.
  5. Wait 2–4 days. It's ready when it tastes clearly tart, about like lemonade, and turns the test liquid pink. Small bubbles and cloudiness are normal. Then start the daily cycle.
Every day

The daily cycle

  1. Taste and test. The brew should taste tart and turn the test liquid pink. If it's purple, skip today's harvest and see Troubleshooting.
  2. Harvest 1 L. Pour it through the strainer with clean hands and a clean funnel.
  3. Bottle it. Leave about 6 cm (2.5 in) of headspace. Add bottle add-ins if you like. For more fizz, add ½ tsp sugar per 500 mL.
  4. Feed the jar right away using the amounts below.
  5. Squeeze and chill. Cap the bottles tight and leave them on the counter. Squeeze them a few times a day. Move them to the fridge when they feel firm with only slight give, usually after 12–36 hours. Drink within a week and open slowly over the sink.

Daily feed

Steep the tea bags in the hot water for 5 minutes, then stir in the sugar and salt. Remove the bags and add the cold water. The mix is cool enough to pour in right away. Use 2 tbsp of vinegar per liter if the brew tasted flat or the test looked purple.

Every 4–7 days

Swap the peels

Remove soft or pale peels with the clean spoon and add fresh ones. Take pineapple skins out after 3 days because they ferment strongly.

When it slows

Add more brine

If bottles take more than 48 hours to firm up, stir in 100–150 mL of fresh cabbage brine.

Monthly

Reset the jar

Save 1 L of brew. Wash the jar with hot soapy water and rinse it well. Restart with the saved liter plus 3 L of fresh sweet tea, 2 tbsp vinegar, ½ tsp salt and fresh peels.

Going away

Pause it

Feed it, tighten the lid and put the jar in the fridge for up to 2 weeks. Let it warm up for a day before your next harvest.

Flavor menu

Choose your peels

Peels in the jar carry wild yeast and set the base flavor. Bottle add-ins go into each bottle and give a fresher taste and extra fizz. Put fresh herbs in bottles only, because they rot in the jar.

Citrus Classic

fizz ●●○○

Jar
1–2 mandarin or orange peels, 3 lemon zest strips (no white pith)
Bottle
Squeeze of lemon

Orchard

fizz ●●●○

Jar
Peel and core of 1 apple, 1 cinnamon stick
Bottle
1 tbsp apple juice

Tepache

fizz ●●●●

Jar
Skin of ¼ pineapple, 1 clove, 3 slices of ginger. Take the skin out after 3 days.
Bottle
1 tbsp pineapple juice

Ginger Zinger

fizz ●●●○

Jar
5 thin coins of fresh ginger, 2 lemon zest strips
Bottle
1 extra ginger slice, ½ tsp honey. Easy on the stomach during training.

Garden Cooler

fizz ●●○○

Jar
Lime zest strips, peel of ½ cucumber
Bottle
3 mint leaves, 2 cucumber slices

Berry Red

fizz ●●●○

Jar
A handful of red grapes, lightly crushed, or apple peel
Bottle
3 frozen berries or a pinch of dried hibiscus. Keep hibiscus out of the jar, because its red color ruins the pH test.

Pear & Spice

fizz ●●○○

Jar
Peel of 1–2 pears, 2 cardamom pods, cracked
Bottle
Small pinch of cinnamon

Tropical

fizz ●●○○

Jar
Mango peel, 1 mandarin peel, lemon zest
Bottle
1 tbsp mango purée

Mango skin contains urushiol, the irritant in poison ivy. Skip it if mango skin or poison ivy makes your skin react.

Keep these out of the jar: moldy or bruised fruit, waxed citrus unless scrubbed in hot water (buy organic if you can), crushed fruit pits or seeds, rhubarb leaves, and anything sprayed or from the roadside.
Swaps

Tea, sugar and electrolyte options

IngredientOptionHow to use it
TeaBlack (default)Tea feeds the microbes and gives the drink body. 2 bags per liter is about 80–100 mg caffeine, the same as 2 cups of tea.
GreenLighter and grassier. Use the same amount.
RooibosCaffeine-free, for evening training. Keep at least 1 black or green bag per liter so the culture gets enough nutrients.
SugarWhite (default)1 tbsp per liter (~12 g). Cleanest taste and ferments most predictably.
Sweeter / endurance2 tbsp per liter (~25 g), for sessions over 90 minutes or if you want more body. Still less than half the sugar of a store sports drink. Bottles get fizzy faster, so check them twice as often.
Brown or raw caneCaramel flavor and trace minerals. Use the same amount.
HoneyUse 1 tbsp in place of 1 tbsp sugar. Raw honey ferments more slowly.
Fruit juice100 mL apple or grape juice replaces about 1 tbsp sugar.
Blackstrap molassesNo more than 1 tsp per liter. Strong flavor, but it adds potassium.
SodiumSalt ¼ tsp/L (default)About 590 mg sodium per liter, inside the usual sports-drink range of 460–1150 mg/L. Use up to ½ tsp on very hot days or if you sweat heavily.
PotassiumCoconut waterUse 200 mL in place of water at bottling (not in the jar) for about +450 mg potassium. It also adds fizz.
Salt substitute (KCl)A pinch, no more than ⅛ tsp per liter, gives about +400 mg potassium. Skip it if you have kidney problems or take blood-pressure medication.
MagnesiumSkipYou get enough from food. Epsom salt works as a laxative, so keep it out.
Your question

Should I add brewer's yeast?

Not as a regular step. The fruit skins already carry wild yeast. Here's what each kind of yeast does:

Won't ferment

Brewer's / nutritional yeast flakes

The yeast is dead. It adds B vitamins and a savory yeasty taste but no fizz. If you want the nutrition, stir it into food.

Avoid in the jar

Active dry, baker's or beer yeast

It crowds out the wild culture. The brew turns beery and less sour, makes more alcohol, and bottles can turn hard in a few hours.

Better boost

Fresh skins, brine, warmth

Apple, grape and pineapple skins are full of wild yeast. Add fresh brine and move the jar somewhere at 24–26 °C.

Only use it as a rescue. If bottles won't firm up after 3 days somewhere warm, add 3–4 grains of dry yeast to one bottle and check it every 2–3 hours.
About alcohol: wild fermentation always makes a little. Fresh harvests usually stay under about 1%, but bottles left warm for a long time get stronger.
Kefir pairings

Kefir sports drinks

Salted fermented-milk drinks like ayran and doogh are traditional thirst quenchers. Kefir plus your tonic makes a tangy, fizzy recovery drink with protein.

Two rules: Keep kefir and kefir grains out of the jar. Milk grains need milk, and dairy spoils a perpetual brew. Mix in the glass and drink the same day. Never seal kefir mixes in a bottle to build fizz.
Post-workout

Classic Ayran

Mix
250 mL kefir, 200 mL cold water or flat tonic, ⅛ tsp salt, 4 mint leaves
How
Shake or blend until frothy

~9 g protein · ~400 mg sodium

Post-workout

Fizzy Doogh

Mix
250 mL kefir, 250 mL chilled fizzy tonic (Citrus or Ginger works best), pinch of dried mint, pinch of salt
How
Pour the tonic slowly into the kefir, because it foams a lot

Light and sparkling

Long sessions

Recovery Lassi

Mix
250 mL kefir, 150 mL tonic, ½ banana or a handful of berries, 1 tsp honey
How
Blend

More carbs for refueling

Kefir whey as a starter

No sauerkraut? Strain kefir through a cloth in the fridge overnight. Use 250 mL of the yellowish whey in place of the 500 mL cabbage brine, and add 1 tsp of salt to the starter batch, since whey has no salt. The thick part left in the cloth is kefir cheese.

Drinking it

Training plan

WhenWhatHow much
30 min beforeTonic, chilled200–300 mL
DuringTonic. Leave dairy out during hard efforts.150–250 mL every 15–20 min in sessions over 45 min
Within 1 hour afterAyran, Doogh or LassiOne glass, about 450–500 mL
Hot daysTonic with ½ tsp salt per literDrink to thirst
Check with a doctor first if you're pregnant, immunocompromised, on a low-sodium diet, have kidney disease, or take blood-pressure medication.
No strips needed

Red-cabbage pH test

Red cabbage juice changes color with acidity. Low pH is what keeps a wild ferment safe.

  1. Make the indicator. Chop 2–3 red cabbage leaves and pour a cup of boiling water over them. After 10 minutes, strain the purple liquid into a jar. It keeps about a week in the fridge.
  2. Set up references. In three white cups, add 1 tbsp water, 1 tbsp vinegar and 1 tbsp of your brew.
  3. Add 1 tbsp of indicator to each cup and compare. Your brew should look close to the vinegar cup and clearly different from the water cup.
Troubleshooting & safety

Mold or yeast? What to look for

Normal

Brown strings or sediment on the bottom

This is yeast. It's harmless. Leave it or strain it out.

Normal

Smooth, clear jelly disc on top

This is cellulose from vinegar bacteria, a baby SCOBY. It's harmless. Remove it or leave it.

Fix

Flat white or cream film, wrinkled or powdery

This is kahm yeast, which is harmless but tastes stale. Skim it off, add 1 tbsp vinegar per liter and harvest more often.

Fix

Tastes like sweet tea after 3 days, or the test looks purple

Stir in 2 tbsp vinegar per liter and 150 mL brine. Don't drink it until the test turns pink.

Fix

Nail-polish or solvent smell

The yeast is stressed from heat or waiting too long between feeds. Harvest, feed and move the jar somewhere cooler.

Fix

Thick, slimy or stringy liquid

Some lactic bacteria do this and it usually clears in a few days. Throw it out if it also smells bad.

Fix

Bottles won't firm up in 48 hours

Move them somewhere warmer, add ½ tsp sugar per 500 mL, use fresh skins in the jar and add more brine.

Fix

Bottles gush when opened

Chill them earlier, at firm instead of hard, and keep them cold for 24 hours before opening. Open slowly over the sink.

Fix

Too sour or too salty

If too sour, harvest more often and cut the vinegar in the feed to 1 tsp per liter. If too salty, leave the salt out of the next 2 feeds.

Discard

Fuzzy, raised or dry spots, or blue, green, black, pink or orange patches

This is mold. Throw out everything, including the peels. Wash the jar with hot soapy water and restart. Skimming mold off doesn't make the rest safe.

Discard

Rotten, putrid or garbage smell, or a blue or green test

Throw it out and restart with fresh brine.

House rules

  • If you're unsure whether it's safe, throw it out. A new batch costs a few tea bags.
  • Wash your hands and use clean utensils. Never dip a used cup into the jar.
  • Use plastic, glass or stainless steel. Acid eats aluminum and copper.
  • Good smells are tart, fruity, bready and slightly like sauerkraut.
Extra · make your own starter

Fermented cabbage

The brine from homemade sauerkraut starts the tonic and recharges it later. You need 500 mL to start and about 150 mL now and then. Choose the quick juice if you want brine in a few days, or full sauerkraut for brine and a side dish.

3–5 days · all liquid

Quick cabbage juice

3 cupschopped green cabbage (about 300 g)
1 Lwater
1½ tspsalt (about 9 g)
  1. Pulse everything in a blender for a few seconds until the cabbage is in small bits, not a smooth purée.
  2. Pour it into a clean jar and leave 3 cm of space at the top. Put the lid on loosely.
  3. Leave it at room temperature for 3–5 days and stir once a day.
  4. It's ready when it smells sour and pickle-like and turns the test liquid pink. Strain it, then keep the juice in the fridge for up to a month.
1–4 weeks · brine + sauerkraut

Classic sauerkraut

1 kggreen cabbage (1 medium head)
20 gsalt, 2% of the cabbage weight (about 1 heaped tbsp)
500 mLextra 2% brine: 10 g salt dissolved in 500 mL water. This gives you more liquid for the tonic.
  1. Take off 2 clean outer leaves and set them aside. Quarter the cabbage, cut out the core and slice it thin.
  2. Sprinkle on the salt and squeeze and massage it with your hands for 5–10 minutes, until it's limp and sitting in its own juice.
  3. Pack it tightly into a jar and press it down hard. Pour in the juice from the bowl and the extra brine.
  4. Cover the top with the saved leaves and weigh them down with a small water-filled jar or a zip bag of brine. Everything must stay under the liquid.
  5. Put the lid on loosely and keep the jar at 18–22 °C out of the sun. Press it down every day for the first few days.
  6. Taste it after 1 week. When it's pleasantly sour, pour off the brine for the tonic and move the sauerkraut to the fridge to eat.
Tips. Use plain salt without iodine if you can find it, since iodized salt can make the brine cloudy. Weigh the salt rather than measuring by spoon: too little lets spoilage in, too much stalls the ferment. Red cabbage works too, but it turns the tonic pink and makes the pH test hard to read. Save 150 mL of old brine to start the next jar faster.
Kraut safety: anything above the brine can spoil. If fuzzy or colored mold appears, throw out the jar. A flat white film is kahm yeast: skim it off and push the cabbage back under the brine.

Got your brine? Go to the starter batch ↑