LoafOfMyLifeHow we calculate hydration
Hydration is the water in a dough as a percentage of the flour. Here is exactly how LoafOfMyLife works it out — and where every figure comes from, so you can check it.
Hydration
The figure bakers use: water and other liquids (milk, buttermilk, beer, yoghurt…) by weight, divided by the flour weight. 350 g of water on 500 g of flour is 70%. Liquids count at their full weight, as they do in recipes and most bakers' spreadsheets, so our figures match the ones you know.
Sourdough starter and discard
A starter is part flour, part water. Its flour is added to the flour total and its water to the liquid — worked out from your starter's own hydration, not its whole weight. Sourdough discard is taken as 100% hydration: half flour, half water.
Total hydration
Some ingredients that aren't liquids still bring water into the dough: eggs are about three-quarters water, butter about a sixth, honey and syrups a fifth or more, and purées like banana or pumpkin mostly water. When a recipe has any of these, the calculator also shows the total hydration, adding the water they carry.
Example: 500 g flour, 250 g milk, 2 eggs (100 g) and 50 g butter. Hydration is 250 ÷ 500 = 50%. The eggs add 76 g of water and the butter 8 g, so the total hydration is 334 ÷ 500 = 66.8% — which is why an enriched dough feels softer than its hydration suggests.
What isn't counted
- The flour's own moisture (usually 12–14%). Bakers never count it, so neither do we.
- Pieces folded through the dough — cheese, olives, fruit pieces, nuts, seeds and chocolate. They keep their water inside them rather than giving it to the dough.
- Dry ingredients — sugar, salt, spices, dried yeast and powders have little or no water.
Quick breads
Quick breads use the same calculation. Batters and soft doughs run much higher than yeast breads — a skillet cornbread is well over 100% — so for quick breads the figure is for comparing and adapting recipes, not a target to hit.
Where the figures come from
Every water figure is taken from USDA FoodData Central, the US Department of Agriculture's food composition database (SR Legacy and Foundation Foods; public domain). Each one links to the USDA's own page for that food. We cross-check them against the UK's official food tables, McCance and Widdowson's Composition of Foods Integrated Dataset (CoFID) 2021. The two agree to within a gram or two for nearly every ingredient; where they differ (yoghurt, egg yolk, molasses, coconut milk) it is because the products themselves differ, and we use the USDA figure.
Natural ingredients vary — a juicier apple, a bigger yolk — so these are standard reference values, not measurements of your ingredients.
Counted in total hydration
| Ingredient | Water per 100 g | Source (USDA) | UK check |
|---|---|---|---|
| Agave Nectar | 22.9 g | USDA 170277Sweetener, syrup, agave | — |
| Almond Milk | 96.5 g | USDA 174832Beverages, almond milk, unsweetened, shelf stable | — |
| Beer | 92.0 g | USDA 168746Alcoholic beverage, beer, regular, all | 93.9 g17-506 |
| ButtermilkCultured buttermilk as sold today is low-fat; CoFID has no buttermilk entry. | 90.1 g | USDA 170874Milk, buttermilk, fluid, cultured, lowfat | — |
| Coconut MilkCanned coconut milk varies by brand and fat content. | 72.9 g | USDA 170173Nuts, coconut milk, canned (liquid expressed from grated meat and water) | 78.3 g14-889 |
| Coffee | 99.4 g | USDA 171890Beverages, coffee, brewed, prepared with tap water | — |
| Cream Style Sweetcorn | 78.7 g | USDA 169215Corn, sweet, yellow, canned, cream style, regular pack | — |
| Egg Yolk | 52.3 g | USDA 172184Egg, yolk, raw, fresh | 48.8 g12-939 |
| Fresh / Cake Yeast | 69.0 g | USDA 175042Leavening agents, yeast, baker's, compressed | 70.0 g17-378 |
| Grated Zucchini | 94.8 g | USDA 169291Squash, summer, zucchini, includes skin, raw | 95.0 g13-627 |
| Honey | 17.1 g | USDA 169640Honey | 17.5 g17-050 |
| KefirThe only plain kefir in SR Legacy is a branded low-fat kefir; CoFID has no kefir entry. | 89.7 g | USDA 170904Kefir, lowfat, plain, LIFEWAY | — |
| Lemon Juice | 92.3 g | USDA 167747Lemon juice, raw | 91.4 g14-277 |
| Malt ExtractLiquid malt extract; the USDA lists it as malt syrup. | 21.1 g | USDA 169660Syrups, malt | — |
| Malt Syrup | 21.1 g | USDA 169660Syrups, malt | — |
| Maple Syrup | 32.4 g | USDA 169661Syrups, maple | — |
| Mashed PotatoHome-made mash with milk. | 78.5 g | USDA 170493Potatoes, mashed, home-prepared, whole milk added | 76.7 g13-553 |
| Melted ButterMelting doesn't change the water in butter; it is weighed after melting. | 16.2 g | USDA 173430Butter, without salt | 14.9 g17-661 |
| MolassesMolasses and black treacle vary by grade. | 21.9 g | USDA 168820Molasses | 25.9 g17-059 |
| Oat Milk | 90.6 g | USDA 2257046Oat milk, unsweetened, plain, refrigerated | — |
| Pumpkin PuréeCanned pumpkin purée. CoFID lists only raw pumpkin flesh (95%). | 90.0 g | USDA 168450Pumpkin, canned, without salt | — |
| Ripe Banana | 74.9 g | USDA 173944Bananas, raw | 75.0 g14-318 |
| Sour Starter | Your starter | From your starter hydration | — |
| Sourdough Discard | Your starter | From your starter hydration | — |
| Soy Milk | 88.1 g | USDA 172446Soymilk, original and vanilla, unfortified | — |
| Unsalted Butter | 16.2 g | USDA 173430Butter, without salt | 14.9 g17-661 |
| Vanilla Extract | 52.6 g | USDA 173471Vanilla extract | — |
| WaterWater is 100% water by definition. | 100.0 g | By definition | — |
| Whole Egg | 76.2 g | USDA 171287Egg, whole, raw, fresh | 76.8 g12-937 |
| Whole Milk | 88.1 g | USDA 171265Milk, whole, 3.25% milkfat, with added vitamin D | 87.6 g12-596 |
| Yogurt | 87.9 g | USDA 171284Yogurt, plain, whole milk | 81.9 g12-184 |
Ingredients we list but don't count (72)
| Ingredient | Water per 100 g | Source (USDA) | UK check |
|---|---|---|---|
| Activated CharcoalDry; no reference entry. | — | No reference entry | — |
| Active Dry Yeast | 5.1 g | USDA 175043Leavening agents, yeast, baker's, active dry | 5.0 g17-379 |
| Almonds | 4.4 g | USDA 170567Nuts, almonds | — |
| Apple Chunks | 85.6 g | USDA 171688Apples, raw, with skin (Includes foods for USDA's Food Distribution Program) | 86.2 g14-319 |
| Avocado Oil | 0.0 g | USDA 173573Oil, avocado | — |
| Baking Powder | 5.0 g | USDA 172803Leavening agents, baking powder, double-acting, sodium aluminum sulfate | — |
| Baking Soda | 0.2 g | USDA 175040Leavening agents, baking soda | — |
| Blueberries | 84.2 g | USDA 171711Blueberries, raw | 85.7 g14-325 |
| Brown Sugar | 1.3 g | USDA 168833Sugars, brown | 0.0 g17-060 |
| Caraway Seeds | 9.9 g | USDA 170918Spices, caraway seed | — |
| Cardamom | 8.3 g | USDA 170919Spices, cardamom | — |
| Cheddar Cheese | 36.8 g | USDA 173414Cheese, cheddar (Includes foods for USDA's Food Distribution Program) | 36.6 g12-346 |
| Chia Seeds | 5.8 g | USDA 170554Seeds, chia seeds, dried | — |
| Chilli CrispMostly oil with fried chilli and crisp bits; no reference entry. | — | No reference entry | — |
| Chilli Oil | 0.0 g | Pure oil | — |
| Chocolate Chips | 0.7 g | USDA 167976Candies, semisweet chocolate | — |
| Cinnamon | 10.6 g | USDA 171320Spices, cinnamon, ground | — |
| Cocoa Powder | 3.0 g | USDA 169593Cocoa, dry powder, unsweetened | — |
| Coconut Oil | 0.0 g | USDA 171412Oil, coconut | — |
| Currants | 17.6 g | USDA 171724Currants, zante, dried | 15.7 g14-074 |
| Diastatic Malt PowderListed by the USDA as barley malt flour. | 8.2 g | USDA 169740Barley malt flour | — |
| Dried ApricotsSoft "ready-to-eat" apricots are much moister than fully dried ones. | 30.9 g | USDA 173941Apricots, dried, sulfured, uncooked | 14.7 g14-031 |
| Dried Cranberries | 15.8 g | USDA 171723Cranberries, dried, sweetened (Includes foods for USDA's Food Distribution Program) | — |
| Dried FigsSoft "ready-to-eat" figs are much moister than fully dried ones. | 30.1 g | USDA 174665Figs, dried, uncooked | 16.8 g14-092 |
| Dried Oregano | 9.9 g | USDA 171328Spices, oregano, dried | — |
| Dried Rosemary | 9.3 g | USDA 171333Spices, rosemary, dried | — |
| Dried Thyme | 7.8 g | USDA 170938Spices, thyme, dried | — |
| Extra Virgin Olive Oil | 0.0 g | USDA 171413Oil, olive, salad or cooking | — |
| Fennel Seeds | 8.8 g | USDA 171323Spices, fennel seed | — |
| Flax Seeds | 7.0 g | USDA 169414Seeds, flaxseed | — |
| Fresh HerbsVaries by herb (USDA: basil 92%, parsley 88%, rosemary 68%). | — | No reference entry | — |
| Garlic-Infused Olive OilAn olive oil base. | 0.0 g | Pure oil | — |
| Ghee | 0.5 g | USDA 171314Butter, Clarified butter (ghee) | 0.4 g17-640 |
| Ground Ginger | 9.9 g | USDA 170926Spices, ginger, ground | — |
| Hazelnuts | 5.3 g | USDA 170581Nuts, hazelnuts or filberts | — |
| Hemp Seeds | 5.0 g | USDA 170148Seeds, hemp seed, hulled | — |
| Icing Sugar | 0.2 g | USDA 169656Sugars, powdered | 0.0 g17-062 |
| Instant Yeast | 5.1 g | USDA 175043Leavening agents, yeast, baker's, active dry | 5.0 g17-379 |
| Jalapeño | 91.7 g | USDA 168576Peppers, jalapeno, raw | — |
| Lard / Shortening | 0.0 g | USDA 171401Lard | — |
| Lemon Zest | 81.6 g | USDA 167749Lemon peel, raw | 81.6 g14-337 |
| Light Olive Oil | 0.0 g | USDA 171413Oil, olive, salad or cooking | — |
| Macadamia Oil | 0.0 g | Pure oil | — |
| Milk Powder | 2.5 g | USDA 170876Milk, dry, whole, with added vitamin D | — |
| Nigella SeedsDry seed; no reference entry. | — | No reference entry | — |
| Nutmeg | 6.2 g | USDA 171326Spices, nutmeg, ground | — |
| OlivesUSDA: ripe black olives; CoFID: green olives in brine. | 80.0 g | USDA 169094Olives, ripe, canned (small-extra large) | 76.5 g14-340 |
| Parmesan Cheese | 30.0 g | USDA 170848Cheese, parmesan, hard | 27.6 g12-526 |
| Peanut (Groundnut) Oil | 0.0 g | USDA 171410Oil, peanut, salad or cooking | — |
| Pecans | 3.5 g | USDA 170182Nuts, pecans | — |
| Pistachios | 4.4 g | USDA 170184Nuts, pistachio nuts, raw | — |
| Poppy Seeds | 6.0 g | USDA 171330Spices, poppy seed | — |
| Potato Flakes | 6.6 g | USDA 170445Potatoes, mashed, dehydrated, flakes without milk, dry form | — |
| Potato Flour | 6.5 g | USDA 168446Potato flour | — |
| Psyllium HuskDry fibre; no reference entry. | — | No reference entry | — |
| Pumpkin Seed Oil | 0.0 g | Pure oil | — |
| Pumpkin Seeds | 5.2 g | USDA 170556Seeds, pumpkin and squash seed kernels, dried | 5.6 g14-842 |
| Raisins | 15.5 g | USDA 168165Raisins, dark, seedless (Includes foods for USDA's Food Distribution Program) | 17.4 g14-393 |
| Roasted GarlicRoasting drives off part of the water of raw garlic (59%); no reference entry for roasted garlic. | — | No reference entry | — |
| Sea Salt | 0.2 g | USDA 173468Salt, table | — |
| Sesame Seeds | 4.7 g | USDA 170150Seeds, sesame seeds, whole, dried | — |
| Sunflower Seeds | 4.7 g | USDA 170562Seeds, sunflower seed kernels, dried | — |
| Toasted Sesame Oil | 0.0 g | USDA 171016Oil, sesame, salad or cooking | — |
| Truffle OilAn olive or sunflower oil base. | 0.0 g | Pure oil | — |
| Vegetable OilSoybean oil, the usual "vegetable oil". | 0.0 g | USDA 171411Oil, soybean, salad or cooking | — |
| Vital Wheat Gluten | 8.2 g | USDA 168147Vital wheat gluten | — |
| Vitamin C (Ascorbic Acid)Pure vitamin C powder. | — | No reference entry | — |
| Walnut Oil | 0.0 g | USDA 171030Oil, walnut | — |
| Walnuts | 4.1 g | USDA 170187Nuts, walnuts, english | — |
| White Sugar | 0.0 g | USDA 169655Sugars, granulated | — |
| Whole Kernel CornCanned, drained. | 81.4 g | USDA 169214Corn, sweet, yellow, canned, whole kernel, drained solids | 78.7 g13-529 |
| Xanthan GumDry thickener; no reference entry. | — | No reference entry | — |