WCA help
Hi,
I keep hearing that wca can be made using oyster shells. Do you make wca the same way you make wca with chicken eggs? I.e. do we have to bake the oyster shells to brown them before putting them in vinegar?
thanks
Top answer
u do not need to roast oyster shells unless u r gathering them yourself then u would want to wash and bake or roast over a heat to clean and kill any bad juju b4 u put in vinegar
From the KNF library
From the KNF library
Drafted by Claude from Office Hours and the books
·
Sep 2026
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4 sources
Drake's library treats oyster shell as a stand-in for eggshell. Cho lists "eggshell or oyster shell" as the WCA material. (Cho, Recipe, p. 59) Both are mostly calcium carbonate. (Cho, Recipe, p. 60)
Cho roasts eggshells to burn out the organic substances. The calcium stays. (Cho, Recipe, p. 60) His method says to add the roasted eggshells or oyster shells to the vinegar slowly. (Cho, Recipe, p. 62)
The library gives two colors for done. One recipe says eggshells turn slightly brown, like a roasted marshmallow. (Cho's Solutions, p. 13) Cho says lightly roasted shells look brighter than the original and get very light. (Cho, Recipe, p. 60)
- Mix 1 part shell with 10 parts brown rice vinegar by weight. (Cho's Solutions, p. 13)
- Dissolve for 7 days. (Cho's Solutions, p. 13)
The library does not say whether cleaned, store-bought oyster shell can skip the roasting.
Sources
- p. 62 Cho, Recipe · “Put the roasted eggshells or oyster shells little by little and slowly into the container with BRV.”
- p. 60 Cho, Recipe · “Calcium carbonate is the main component of eggshells and oyster shells.”
- p. 13 Cho's Solutions · “Eggshells will turn slightly brown (like a perfectly roasted marshmallow) when done”
- p. 59 Cho, Recipe · “Eggshell or oyster shell which contains an abundant amount of calcium.”
1 more answer
Thank you. I bought a bag of oyster shells for making wca since it’s faster then collecting enough egg shells. Gonna give this a try. Strawberries are already starting to flower and fruit. Would have made it ahead of time but had to leave town for a couple weeks and just got back Friday. :)
