Kombucha Second Ferment Cost Calculator

See how much bottled kombucha you save per case.

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Frequently Asked Questions

What should I include in the first-ferment batch cost?
Include all consumables for that batch: tea bags or loose-leaf tea, white sugar (and any raw or specialty sugar), and filtered water if you pay for it. Do not include SCOBY cost — a healthy SCOBY reproduces indefinitely and is effectively free after your starter purchase. Divide your total by the number of bottles produced to get a per-bottle figure.
How do I amortize my swing-top bottle cost?
Take the price you paid per bottle and divide by the expected number of uses. Quality 16-oz Grolsch-style bottles typically last 50–200 fill cycles with proper cleaning. At 100 uses and $2.00 per bottle, the amortized cost is $0.02 per bottle — so even expensive bottles add very little to your per-bottle cost in the long run.
Should I count my time as a cost?
This calculator focuses on out-of-pocket material costs, which is the most direct comparison to a store price. If you want to factor in labor, estimate your active brewing time (not passive fermentation time), apply an hourly rate, and add that divided by bottle count to your total. Most brewers find the active hands-on time is 20–30 minutes per batch, making labor a small factor even at high hourly rates.
Why is homemade kombucha so much cheaper than store-bought?
Store-bought kombucha prices include packaging, pasteurization or refrigeration logistics, retail markup (often 40–60%), and brand marketing. The raw ingredients — tea, sugar, water, and fruit — are inexpensive. Home brewing cuts out every middleman and most of the packaging cost, which is why the savings are so dramatic even when you use premium organic ingredients.
How many batches does it take to break even on startup equipment?
Typical startup costs for home kombucha brewing (a gallon jar, bottles, a starter SCOBY, and a heating mat) run $40–$80. If you save $2.50 per bottle and produce 8 bottles per batch, each batch saves you $20. You break even in just 2–4 batches — often within the first month of brewing.

How to Calculate the True Cost of Your Second-Ferment Kombucha

Home brewers often underestimate what a bottle of homemade kombucha actually costs because the expenses are spread across several steps. The three real cost drivers are the first-ferment tea batch (tea, sugar, and a fraction of your SCOBY's lifespan), the second-ferment flavoring (juice, fruit puree, ginger, herbs), and the amortized bottle cost for your swing-top or flip-cap bottles.

To find your first-ferment cost per bottle, total everything you spent on the batch — loose-leaf or bagged tea, sugar, filtered water if applicable — then divide by the number of bottles you filled. A typical one-gallon batch fills about four 16-oz bottles, while a two-gallon batch fills eight. Most home brewers run $1.50–$3.00 per gallon for tea and sugar combined.

Flavoring costs vary widely. Fresh mango or berry puree runs higher than a splash of bottled juice. A rule of thumb is 1–2 oz of juice or 1–1.5 oz of fruit per 16-oz bottle. Track what you actually spend per batch and divide by bottle count for an accurate number.

Swing-top bottles (Grolsch-style, 16 oz) retail for $1.50–$3.00 each new, or $0.50–$1.00 at thrift stores. Because they last for years with proper care, you amortize the cost. Assuming 100 uses per bottle, a $2.00 bottle costs $0.02 per use — almost nothing.

Compared to store-bought kombucha — typically $3.99–$5.49 per 16-oz bottle — most home brewers land between $0.75 and $1.75 per bottle fully loaded. That is a savings of 60–80% per bottle, or $30–$45 per case of 12. Over a year of weekly brewing, the savings can easily exceed $300.