Scum or yum?

Scum or yum? Another no-waste day in the kitchen.

This week I was making a batch of broth from beef knuckles.  And apple vinegar. That’s all. I noticed after it came to the boil that there was a lot of grey foam; it looked almost spongelike, as if it was taking on a whole life of its own.

When you’re cooking for humans, you learn dépouiller, i.e. removing this scum from the surface until all impurities are gone and you’re left with a clear stock. As I automatically reached for the slotted spoon to start skimming, I wondered what this strange stuff actually consists of. So instead of throwing it away, I collected it. Before I’d had a chance to even find out, I noticed that its appearance had changed, its consistency was different, as if the air had gone out of it, and it looked almost meat-like. I gave some to one of the dogs, who did one of those whiplash double-takes she does when something is exceptionally – and perhaps unexpectedly – extra delicious.  That’s why there isn’t as much in the photo as there would otherwise have been.😋

What’s in it?

Anyway, it turns out that my instincts were right – this absolutely should not be thrown away. This foam isn’t just one substance but a combination of different components, primarily proteins, along with a mix of other water-soluble compounds that are released from the bone and connective tissue as the water heats:

• albumin and globulins – soluble proteins from muscle and connective tissue that denature with heat (lose their natural shape but not their ‘building blocks’) form much of the foam;
• myoglobin – the oxygen-carrying protein in muscle; when it denatures it darkens, adding to the grey-brown colour;
• residual blood solids – traces from marrow and tissue fragments;
• fat and mineral salts – small fat globules emulsify into the froth, with salts released from the bones concentrating at the surface;
• tissue fragments – tiny shreds of muscle or connective tissue caught up in the coagulated proteins.

So what I’d collected was a protein-rich composite with a little fat and mineral content – not harmful, just less appealing for chefs aiming for a clear, “refined” broth.

Now, what to do with it? Well, it just so happens that I’d been experimenting with amaranth at the same time as the broth was simmering. I’d made a couple of puddings as a basis, to be let out with liquids and completed with other ingredients. How fortuitous… ;-)

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Making a meal

First, I spooned the remaining ‘foam’ into a blender. Before continuing, I let my kitchen assistants clean up, just to check the palatability factor:

 

Palatability confirmed, I added some amaranth pudding (see recipe here):

 

And then stirred in a good dollop of kefir:

 

This was a nutritious topping, together with meat and fat that fell off the bones in the broth and a sprinkling of hemp seeds.

 

So, lesson learned. Another ingredient that is probably wasted every day. But not in this house!

 

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Important Considerations:

• Always consult your veterinarian before making any significant dietary changes, particularly where there are pre-existing health conditions or dietary restrictions.
• If you are feeding commercial food, check the label for ingredients before giving more. Excessive intake of any foods can have adverse effects.
• Ensure (where possible) that you use high-quality, organic products specifically formulated for pets (or better still, human grade ingredients) to avoid any potential adverse effects.
• Introduce new foods gradually to avoid adverse effects such as gastrointestinal upset or diarrhoea.
• I provide nutritional information purely as a helpful guide. Nutritional information on ingredients is obtained from the US Department of Agriculture’s FoodData Central site (https://fdc.nal.usda.gov/index.html) and any nutritional information provided in recipes is based on an online calculator: calories and other information will vary based on brands, ingredients and other factors.
• Check nutrient levels and recommendations for your dog’s weight, age and activity. For example this nutritional guideline produced by FEDIAF.
• I am not a professional canine nutritionist but supporting research is cited.
• The recipes shared were created by me and tested in my kitchen – and tasted and approved by our doggy friends!