Guide
Converting historical recipes: ounces, gills, and 'a moderate oven'
Gill, pottle, 'butter the size of an egg'. Five eras of recipe vocabulary translated.
A recipe from 1925 calls for “half a gill of cream, a wineglass of sherry, and butter the size of an egg, all baked in a moderate oven.” You want to actually make the dish. None of those units are on your scale. Here’s the translation key.
Volume units that disappeared
| Historical unit | Modern equivalent |
|---|---|
| Gill (UK) | 142 ml (¼ imperial pint) |
| Gill (US) | 118 ml (½ US cup, ¼ US pint) |
| Wineglass | 60 ml (2 fl oz) |
| Teacup | 175 ml (informal; varies) |
| Tumbler | 240 ml (1 cup-ish; very informal) |
| Breakfastcup | 240-280 ml |
| Coffee-cup | 175 ml (½ US cup is the modern equivalent) |
| Pottle | 2 quarts ≈ 2.27 L (extinct outside antiquarian texts) |
| Saltspoon | ¼ teaspoon ≈ 1.25 ml |
| Dessertspoon | 10 ml (UK, between teaspoon and tablespoon) |
Weight units that drifted
Pre-1959 international yard-and-pound agreement, the UK and US pound differed by a tiny amount. For practical purposes treat any pre-1959 pound as 453.6 g; the sub-gram difference doesn’t affect cooking.
Other archaic weight units:
- Stone: 6.35 kg (UK, still used for body weight)
- Quarter: 11.34 kg (UK, ¼ hundredweight)
- Drachm (apothecaries’): 3.89 g — appears in some old medicinal-cookery
- Scruple: 1.30 g — same medicinal source
The “size of an egg” problem
Pre-electric-scale cookbooks describe small quantities by comparison to familiar objects. The translations:
- Butter the size of a walnut: ~15 g (1 tablespoon)
- Butter the size of an egg: ~50 g (3-4 tablespoons)
- Lump of sugar: ~6 g (a cube)
- Pinch of salt: ~0.3 g (between fingertips)
- Dash: ~0.6 ml (a quick splash)
Oven temperatures, when ovens didn’t have thermometers
Pre-1920s ovens were wood- or coal-fired with no thermostat. Recipes called for temperatures by feel and baker’s test. The standard translations:
| Description | °F | °C | Gas Mark |
|---|---|---|---|
| Cool / very slow | 250 | 120 | ½ |
| Slow | 300 | 150 | 2 |
| Moderately slow / warm | 325 | 165 | 3 |
| Moderate | 350 | 180 | 4 |
| Moderately hot / brisk | 375 | 190 | 5 |
| Hot | 400 | 200 | 6 |
| Very hot / quick | 450 | 230 | 8 |
The traditional “baker’s test” was to put a handful of flour on the oven floor: if it darkened slowly, the oven was moderate; if quickly, hot; if instantly, very hot. Modern thermostats made this obsolete by the 1930s in commercial kitchens, 1950s at home.
Ingredients that disappeared or shifted
- “Suet”: hard fat from around beef kidneys. Still available from butchers, fading fast. Substitute: equal weight of unsalted butter for sweet recipes; lard for savoury.
- “Treacle”: dark cane syrup. Modern equivalent: blackstrap molasses (US) or golden syrup + 30% molasses (UK approximation).
- “Pearl ash”: pre-baking-soda chemical leavener (potassium carbonate). Modern recipes substitute baking soda 1:1 — close enough.
- “Cream of tartar + sodium bicarbonate”: the pre-1880s home version of baking powder. Modern baking powder is the same chemistry premixed.
- “Yeast cake” (fresh pressed yeast): use ⅓ the weight of instant yeast.
The pragmatic workflow
- Read the whole recipe. Identify every non-modern unit.
- Convert volumes and weights using the tables above.
- Convert oven temperatures (use our oven temperature converter).
- Substitute disappeared ingredients with modern equivalents.
- Halve the recipe on first try if it’s an unfamiliar dish — historical recipes assumed bigger family sizes.
- Take notes for the next time. Historical dishes often need 2-3 attempts to dial in to modern taste.
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Published May 15, 2026