Kombucha Brewing

Plan a batch of kombucha and find out what it costs you.

Set your batch size and recipe, and the app works out how much tea, sugar, and flavoring you need, how many bottles you will fill, what the whole batch costs, and what you make selling it.

Running it

The app is deployed at https://kylebarrett.shinyapps.io/Kombucha/

To run it yourself, open the project in RStudio and run:

renv::restore()
shiny::runApp()

renv::restore() installs the exact package versions the app was built against, and only needs running the first time.

Using it

Brew Setup is where you describe the batch.

Start with the batch size and the starter ratio – the share you carry over from your last batch. Everything else scales off what is left, since that is the volume you actually brew.

The three tabs below follow the brew:

• F1 Ingredients – tea, sugar, and whether you cool with water or ice. Enter prices the way you paid them (a box of 600 tea bags for $21.00) and the app works out the per-bag rate.
• F2 Flavoring – choose regular kombucha, hard, or a split of both, then pick flavorings for each. Amounts scale with how much of each style you make.
• Bottling – bottle size and how much juice goes in each one. Bottles are priced by the case, caps individually.

Each tab totals its own costs as you go.

Cost Analysis puts the whole batch together: what it cost, broken down by stage, and what you make at a given sell price – including how many bottles you need to sell to break even.

Ingredient Library is the list of flavorings you can choose from. Double-click any cell to change an amount or a price, and the batch re-prices straight away. Add and delete rows as your shelf changes. Changes only last the session until you hit Save library, and Restore defaults puts the original list back. Download CSV gives you a copy to keep or share.

Development

Run the tests from the R console:

testthat::test_dir("tests/testthat")

The browser tests need Chrome installed.