Name: To Preserve Butter
Ingredients: 1 oz saltpetre; 2 oz sugar; 2 lbs coarse sea salt (formerly 'bay salt'); 1 qt boiling water

To Preserve Butter

A method for preserving butter by submerging it in a clear pickle made from saltpetre, sugar, coarse sea salt, and boiling water.

From an old cookbook · modernised transcription

From a historical cookbook (Internet Archive) · 4 ingredients

To Preserve Butter

Ingredients

1 oz saltpetre
2 oz sugar
2 lbs coarse sea salt (formerly 'bay salt')
1 qt boiling water

Directions

Combine saltpetre, sugar, and salt in a pan.
Pour boiling water over the mixture.
Let it cool, then strain the liquid.
Submerge the butter in the clear pickle to preserve it.

Recipe from a historical cookbook (Internet Archive).

Transcribed from a scanned cookbook and modernised for today's kitchens. Where the book gave no heat or time, or said "a moderate oven", the temperatures and times here may be modern equivalents rather than the book's own figures.

Explore the science

What each ingredient does

Saltpetre: Acts as a curing agent that helps preserve the butter and keeps its color stable.
Coarse sea salt: Draws moisture out and inhibits microbial growth, helping preserve the butter in the brine.
Sugar: Balances the saltiness and adds mild sweetness to the pickle.

“What each ingredient does” and “The step that matters” were written by Claude from this recipe’s own method and reviewed in samples by CompKitchen.