Animal fats

Lard, tallow, suet, dripping – animal fats that were ubiquitous before the modern era (mid-twentieth century) without obvious health issues.

Then, as we became more sedentary and convenience foods became, well, more convenient, we gained weight and looked for a culprit (other than ourselves). It was easy to blame fat for making us fat, and this was soon legitimised in nutritional advice. Because the idea was plausible we listened, banishing these fats from our kitchens and diets. In many cases they have been erased from our culture.

The thing is, given the steady rise in obesity, cardiovascular disease and metabolic diseases, we don’t seem to be any better for it. We ate animal fats for millennia – indeed, throughout the evolution of our species. It is unlikely that our evolutionary biology would have penalised us for eating animal fats. They are heritage fats. The grain/seed/nut oils we are urged to replace them with have only appeared relatively recently. Maybe we acted too hastily or listened too uncritically.

Heritage fats are natural products that need only be rendered (melted out of the cellular structures holding them) or separated (as for butter). They come with co-nutrients. They are flavourful or improve the flavour and texture of other foods. They can give a sense of fullness that leads to satiety.

So, here’s a heritage fat primer. Lest we forget.

Lard

Lard is rendered pig fat, usually from the back fat (the thick layer of fat on the back of the animal). Leaf lard comes from fat deposited around the internal organs. Other fats not normally rendered are belly fat (more likely to be cured for bacon) and caul fat (a lacy fat surrounding the intestines and prized as a juicy wrapping).

Lard’s saturated fatty acid content is around 40% (two thirds palmitic and one third stearic). Stearic acid is interesting because we convert some of this saturated fatty acid to mono-unsaturated oleic acid on digestion (oleic acid is the main fatty acid in olive oil), and because it has been shown to have no effect on blood cholesterol (LDL) and can even reduce it in high doses.

lardThe unsaturated component of lard (i.e. the other 60%) is mostly made up of oleic acid (50%; see above) and the poly-unsaturated linoleic acid (~10%). Linoleic acid is an essential omega-6 fatty acid (essential means our bodies need it but don’t manufacture it, so it must be eaten).

Lard is remarkably high in vitamin D, but only if the pig is pastured.

In cooking, leaf lard is prized for pastry because its large crystalline structure makes the dough flakey. Back fat is good for frying because the saturated fatty acids resist oxidation on heating, it has a high smoke point (210C) and it is odourless (it does not impart the smell or taste of pork to food).

images-9As we increasingly heeded dietary advice, pig farmers were obliged to breed ever leaner pigs to meet demand for that ‘other white meat’. The result is that modern pigs carry much less fat (and flavour) than their forebears and lard is now difficult to source.

If you are wondering how thoroughly we embraced the ‘eat less animal fat’ message, annual consumption of lard in the US in 1950 was more than 5 kg; by 1995 it was 180 g. That’s about a three thousand-fold reduction in only a 45 year period. If there was any link between animal fat and obesity, Americans should be gaunt.

Commercially-available lard will come from any available pig fat and may be partly hydrogenated for texture (check the trans-fat level). It may also be treated with bleaching and deodorising agents, emulsifiers and antioxidants for appearance and to retard spoilage. Instructions on how to render your own lard are at the end of this post.

Tallow

Tallow is rendered beef or lamb fat. It is around 50% saturated and 46% unsaturated (42% mono-unsaturated). It contains vitamins E and D.

Australian-livestock-exporters-demand-Egypt-actionTallow is ideal for deep frying because its high saturated fat makes it stable and resistant to oxidation and because food cooked in it is less greasy. Be aware though that, unlike lard, it will imbue a beefy flavour to the food and aroma to the kitchen.

In the 1990s McDonalds gave in to naive consumer pressure and replaced their beef tallow with unsaturated vegetable oils for frying. These oils were partially hydrogenated and contained unhealthy trans-fats. Further, unsaturated oils are more unstable that saturated fats and can develop trans-fats or break down into other undesirable molecules with repeated heating. To maintain the flavour-profile, McDonalds added hydrolysed wheat and milk proteins to contribute beefiness (from the amino acids). Finally, the fries became greasier – fries cooked in beef tallow absorb about half the fat of those cooked in vegetable oil. Thats what I meant by the phrase ‘naive consumer pressure’ – did this pressure create healthier chips?

Suet

Suet is rendered beef fat from deposits around internal organs (especially the kidneys). Strictly speaking, leaf lard is a form of suet, and suet could be made from lamb fat too, however in culinary terms it is associated with beef. It is one of the most nutrient-rich of the fats: 52% saturated, 35% unsaturated (32% mono-unsaturated); 1.5% protein; 4% water; vitamins – E, K, B6, B12, folate, thiamin, riboflavin, niacin; minerals – zinc, sodium, phosphorus, potassium, magnesium, iron, calcium. Some of these are in trace amounts.

Chicken fat

Remember the ‘take the skin off the chook’ campaign? The fat that goes with it is two-thirds (66%) unsaturated (45% mono-unsaturated) and contains vitamins E and D. Rendered chicken fat is sometimes known as schmaltz.

Butter

Butter is about 50% saturated and 25% unsaturated (21% mono-unsaturated). It is relatively high in water content (18%), which is why pure fats may contain about 9 Calories per gram whereas butter contains around 7.

images-10Butter is about 3% trans-fat (conjugated linoleic acid, CLA). This trans-fat occurs naturally in ruminants (sheep, cows) that are fed on pasture (not grain-fed). CLA is known to have significant anti-cancer properties and might reduce the risk for cardiovascular disease. CLA is taken by some as a supplement for weight management. Other significant dietary sources of CLA are kangaroo meat and eggs. CLA was given the coveted ‘generally recognised as safe’ (GRAS) classification by the FDA in 2008, meaning the FDA does not regulate this natural trans-fat. Meanwhile, the FDA has given notice that after 2016, all industrially-produced trans-fat will be banned in food manufacture and cooking.

Vitamins in butter include A, E, K, B6, B12, folate, thiamin, riboflavin, niacin. Minerals: zinc, sodium, phosphorus, potassium, magnesium, iron, calcium.

Dripping

Dripping refers to any fat that has been dry-rendered. Fat released onto the pan when roasting meat is a form of dry-rendering. Dripping has a similar nutrient profile as the source fat, usually with some additional sodium and flavours. It is worth accumulating dripping as a byproduct of roasting meats or cooking bacon. When cooled, dripping separates into flavoured fat and a flavourful gel. The gel can be added to stocks, sauces, stews etc.

Rendering

Traditionally, fat can be wet-rendered in a low (120C) oven (requiring little attention) or on the stovetop (more demanding). Add about 20% water (e.g. 100g water for 500g fat). Cut the fat into as fine a size as you can be bothered (or pulse in a food processor without allowing the fat to heat). Render for 4-8 hours, uncovered, stirring occasionally (oven) or regularly (stovetop). Strain and store refrigerated (up to 2 months) or freeze (1 year).

The purpose of the water is to stop the fat sticking to the pan before some fat has the chance to render out – the water is evaporated off as rendering proceeds.

Sous vide is probably the least messy (and smelly) option – vacuum pack without water and cook at 85C for a few hours (or as long as necessary). Strain. If there was any water in the fat then it won’t have had the chance to evaporate in the sealed bag. The strained fat can be simmered just above the boiling point of water (e.g. at 120C) until it stops making bubbles. Alternatively, refrigerate the fat until it solidifies and can be separated from the water (the water will be a flavoursome gel and can be used to enrich a sauce, for example).


Heritage fats, in retrospect

They are not as scary as that after all. We are poorer for their eradication from our diets and culture. Our health may have been adversely affected. The message is not to eat more fat but rather to treat fats more equally. Fats are not binary – they cannot be divided into good and bad. The scientific evidence for the saturated fat message is more uncertain than you might think. So, be wary of simplistic nutritional messages, our bodies are more sophisticated than that.


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Related posts:

A fats explainer (saturated, unsaturated, trans etc): http://www.6xc.com.au/beginners-guide-fat/

Health and saturated fats: http://www.6xc.com.au/dietary-saturated-fat-cardiovascular-disease/

Bacon fat: http://www.6xc.com.au/bacon-2/