First, name the job the dairy is doing
Milk is its own guide (see which plant milk for which job). Everything else dairy does in a kitchen breaks into four jobs. Fat coats flour proteins and keeps a pastry short, or carries flavor and browning in a pan. Protein sets a custard, curdles into curds, or builds the stretchy network that lets a cheese melt. Acid reacts with baking soda for lift and tenderizes gluten, which is buttermilk and yogurt's real contribution to a biscuit. Structure and melt come from how much of each a specific dairy product carries. Name the job before you shop, because the plant world has a strong answer for each one and a weak answer for guessing.
By federal standard, butter is at least 80 percent milkfat by weight, with water and milk solids making up the rest. Heavy cream is defined the same way at a minimum of 36 percent milkfat. Those two numbers explain almost everything below: a substitute that hits the fat percentage behaves like the dairy it replaces, and one that falls short doesn't, no matter how good the label looks.
| Dairy item | The job | Swap in | Ratio | Watch out for |
|---|---|---|---|---|
| Butter, baking | Fat, for a short and flaky crumb | Vegan block butter (not oil) | 1:1 by weight | Chill hard before laminating; softer brands spread instead of layering |
| Butter, browning | Fat plus moisture for a browned pan | Vegan butter or refined coconut oil | 1:1 | Coconut oil has zero water, so it won't foam or brown the way dairy butter does |
| Heavy cream, whipped | 36%+ fat trapping air | Canned coconut cream, chilled overnight | 1:1, solids only | Only the separated fat layer whips; the watery part underneath won't |
| Heavy cream, sauces | Fat plus body, no strong flavor | Cashew cream, blended smooth | 1:1 | Needs a real blend; a gritty blend never fully smooths in the pan |
| Cream cheese | Fat and protein for a spreadable set | Cashew or store-bought vegan cream cheese | 1:1 | Add lemon juice and salt; most plant versions are blander until seasoned |
| Cheese, melting | Fat and starch for stretch and pull | Starch-based vegan shred | 1:1 | Melts and softens; almost none actually stretch like mozzarella (see below) |
| Yogurt, baking | Moisture, acid, and protein | Unsweetened soy yogurt | 1:1 | Coconut yogurt is thinner on protein, so it tenderizes less |
| Buttermilk | Acid plus protein for tang and lift | Soy milk + 1 Tbsp lemon juice or vinegar | 1 cup + 1 Tbsp, rest 5 min | Only soy has the protein to actually curdle; almond milk just gets sour |
Butter's job is fat, and the water content is the catch
A pastry stays short because solid fat coats flour proteins and physically blocks the gluten network from tightening up. That part any solid fat can do. The part that trips people up is water: dairy butter carries roughly 16 to 18 percent water, and in a laminated dough (croissants, pie crust, puff pastry) that water flashes to steam in the oven and pushes the layers apart. A dedicated vegan block butter is formulated to carry water the same way, which is why it lists it as an ingredient. Plain refined coconut oil is essentially all fat and no water, so it swaps fine in a melted-butter recipe like a blondie, but a lamination made with straight coconut oil bakes flatter and greasier than one made with dairy butter or a real vegan butter block.
Cream's job is a fat percentage, full stop
Whipped cream holds its shape because enough fat surrounds and stabilizes the air bubbles beaten into it; below the federal 36 percent minimum, cream won't whip at all, which is why a recipe calling for heavy cream never works with the light stuff. Full-fat canned coconut milk mimics this if you chill the can overnight: the fat separates out and rises, and that solid layer, skimmed off the watery coconut water underneath, whips the same way. Skip the light or reduced-fat cans; they don't carry enough fat to separate. For savory sauces and soups where whipping doesn't matter, a smooth cashew cream carries body without coconut's flavor announcing itself, though it can thin out again if the sauce hits a hard boil.
Cheese melts fine. Stretch is the part that doesn't fully work
Dairy mozzarella stretches because milk's casein proteins cluster into micelles that build a three-dimensional net, cross-linked by calcium acting as a kind of glue. Heat and kneading that curd (the technique is literally called pasta filata, 'spun paste') align the casein into long parallel fibers, which is the mechanical reason a fresh mozzarella pulls into ropes instead of tearing. Plant cheeses don't have casein, so they lean on starch, oil, and other proteins to melt, and starch alone tends to soften and spread rather than stretch. That's the honest limit of this swap: a good starch-and-oil shred melts convincingly on a pizza, but almost nothing sold at retail pulls an actual string the way fresh mozzarella does. Treat 'melts' and 'stretches' as two different claims, because a label that says one doesn't promise the other.
-
A dedicated vegan butter block (not a spreadable tub)
Formulated with real water content, unlike plain coconut oil, so it laminates, creams with sugar, and browns closer to how dairy butter behaves in a recipe written for it.
-
A starch-based vegan shred for pizza and grilled cheese
Coconut oil plus modified starch gets a genuine melt in a hot oven or a skillet, which is the job most home cooking actually needs from cheese.