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Birdaday Field Notes

Feeding reference

Suet for birds: recipes, rendering and hot-weather rules

Suet is fat offered to birds as a high-energy food. Project FeederWatch calls it "a good choice for attracting insect-eating birds," and the Cornell Lab of Ornithology notes that animal fat is easily digested by many birds. The catch is heat. This page covers the types of suet, three published recipes with amounts exactly as printed, how to render beef fat, and each source's temperature limits. For where to hang a suet cage, see bird feeder types.

Raw, rendered and heat-stable suet

Cornell defines suet as "the hard fat around the kidneys and loins in beef and mutton." FeederWatch says most suet sold for birds is beef kidney fat, which is inexpensive and available at many meat counters. What matters most is whether the fat has been rendered.

Type What it is How it handles heat Source
Raw suet Unprocessed beef fat, cut in chunks Grows rancid quickly above freezing; offer in winter only Cornell Lab
Rendered suet Fat melted with the impurities removed; this includes most suet sold as bird food Stays hard up to about 90°F (32°C), then softens Cornell Lab
Suet cakes Blocks of suet or a thick substitute mixed with cornmeal, peanuts, fruit or dried insects Cakes with corn, cornmeal or peanuts are best kept refrigerated until used Cornell Lab
Shortening and nut-butter mixes Homemade blocks with no animal fat Audubon: not recommended above 50°F outdoors Audubon
Lard-based cakes Lard mixed with peanut butter and seed Softens faster in heat than true suet UF/IFAS Extension
Heat-stable ("no-melt") products Commercial formulations that Cornell says are stable at hotter temperatures Some makers state over 100°F without melting; that is the maker's claim Cornell Lab

Two fats to skip: Cornell lists bacon drippings as "not recommended" because bacon nearly always contains nitrosamines, and Audubon says turkey fat melts faster and goes rancid more quickly. Audubon notes that beef or lamb fat is the usual recommendation.

Recipe 1: Audubon's shortening and nut-butter suet

Published by the editors of Audubon magazine (2016), who credit the recipe to "The Misfit Baker" blog. It is aimed at woodpeckers, wrens, chickadees, nuthatches and titmice.

Amount Ingredient
1 1/2 cups Shortening (Audubon suggests palm-oil-free options)
3/4 cup Nut butter, any kind
3 1/2 cups Wild bird seed
1 cup Quick oats
1/2 cup Corn meal
— Ice cube tray
  1. Mix the bird seed, oats and corn meal together and set aside.
  2. Melt the shortening and nut butter together in a separate bowl and stir until completely combined.
  3. Pour the melted mixture into the dry ingredients and stir until combined.
  4. Spoon the mixture into the ice cube tray.
  5. Freeze for one to two hours, then place the blocks in a suet feeder.

Audubon's note: not recommended for outdoor temperatures above 50 degrees.

Recipe 2: "Marvel Meal" (Penn State Extension)

University of Illinois Extension printed this peanut-butter recipe in 2018, crediting Penn State Extension.

Amount Ingredient
1 cup Peanut butter
1 cup Vegetable shortening
4 cups Cornmeal
1 cup Flour
One handful Sunflower seeds (optional)

The post gives three ways to serve it: press the mixture into holes in a log, smear it directly on tree trunks, or freeze it in blocks for a suet feeder or feeder tray. It gives no mixing method. Because it is peanut-butter based, Cornell's peanut-butter advice applies: offer it when cold keeps it firm, and never leave it out long enough to become soft or rancid.

Recipe 3: rendered beef suet cakes

This combines the rendering method of the Georgia Department of Natural Resources with the straining, ratio and molding advice in Audubon's "Holiday Cooking for the Birds" (2011).

  1. Get the fat. Suet is sold at bird-food stores and butcher shops. Audubon notes that some meat counters will give away beef fat trimmings and run them through a meat grinder if you ask.
  2. Cut it small. Cut the fat into small pieces (Georgia DNR).
  3. Melt it gently. Put the pieces in the top of a double boiler, with water in the bottom pan, over low heat. Georgia DNR warns that suet that gets too hot can catch fire. Audubon says to melt it until liquid, with no meat traces left.
  4. Strain it. Pour the liquid fat through cheesecloth or a fine strainer, at least twice (Audubon).
  5. Add dry ingredients. Audubon suggests starting with 1 cup fat, 1 cup flour and 1 cup other add-ins, and says proportions vary. Add-ins it lists: cornmeal or flour, oats, chopped pecans, unsalted peanuts, sunflower seeds, dried crumbled bread, dried chopped apples or berries, cracked corn, raisins or craisins.
  6. Mold it. Pour into tuna cans, jar lids or cupcake pans (Georgia DNR), or cupcake liners in a muffin tin or empty egg cartons (Audubon). Add twine or yarn if you want to hang it from a branch.
  7. Chill it. Audubon freezes the suet in its mold for two hours before setting it out. Georgia DNR says to let it cool and keep it in the freezer until you use it.

Raw suet needs no recipe: Georgia DNR says it can be cut into chunks for a hardware-cloth feeder. Offer it only in freezing weather (Cornell).

Hot-weather rules

Cornell says suet softened above about 90°F can muss feathers, affecting how they work, and in incubating birds may pass a greasy layer onto eggs and endanger them; soft fat can also clog the pores of eggs.

Suet temperature guideA temperature bar from cold on the left to hot on the right, marked at 32, 50, 70, 90 and 100 degrees Fahrenheit. Below it, three bars show how far each kind of suet stays within its source's limit: raw suet up to freezing, homemade shortening mixes up to 50 degrees, and rendered suet up to about 90 degrees. 32°F50°F70°F90°F100°F 1 2 3 4 5 6 7 8 Raw suet Homemade shortening mixes Rendered suet
  1. 32°F, freezing: above this, raw suet grows rancid quickly (Cornell).
  2. 50°F: Audubon's limit for its shortening recipe; its 2011 article says to be careful above fifty degrees.
  3. 70°F: Georgia DNR says suet melts and spoils rapidly above this.
  4. About 90°F (32°C): rendered suet stays hard up to here, then softens enough to muss feathers (Cornell).
  5. 100°F: some manufacturers state their blocks withstand temperatures over 100 degrees without melting; Cornell still advises taking suet feeders down in warm weather.
  6. Raw suet: freezing weather only.
  7. Homemade shortening mixes: up to 50°F.
  8. Rendered suet: firm up to about 90°F. Green = within the source's stated range; pink dashed = beyond it.
Drawn for Birdaday Field Notes from the temperatures given by the Cornell Lab of Ornithology (All About Birds), Audubon and the Georgia Department of Natural Resources, all cited below. The bar runs from cold to hot; spacing between marks is approximate. Not to scale.

Which birds eat suet

Source Birds named
Cornell feeder guide Woodpeckers, nuthatches, chickadees, titmice, starlings, jays; sometimes Carolina Wrens and Pine Warblers
Cornell suet article Occasionally wrens, creepers, kinglets, cardinals and some warblers
Audubon (2011) Insect-eaters such as wrens, warblers and creepers
Georgia DNR More than two dozen species, including Carolina Chickadee, Tufted Titmouse, American Robin, Brown Thrasher, Pine Warbler, Northern Cardinal, Summer Tanager, Northern Mockingbird, kinglets and woodpeckers

Starlings are very fond of suet, Cornell says. A cage that opens only at the bottom makes birds hang upside down to feed: woodpeckers, nuthatches and chickadees manage it, starlings tend not to (FeederWatch; Cornell; Illinois Extension).

Feeder and storage checklist

Other foods: what to feed backyard birds. A winter suet cage also brings in woodpeckers for slow days of a Bird-a-Day streak.

Sources