I’m trying to stay strictly primal/paleo, but I always run into problems when I need to thicken sauces or soups. I grew up learning to use flour/cornstarch like everyone else, but is there a good low-carb/primal alternative?
I received this email a few weeks ago, but it wasn’t the first. A number of readers have expressed their confusion when it comes to thickening sauces, gravies, or soups without using traditional floury methods. The question of thickening sauces is one of the hurdles I face every time I put up a recipe post – it’s become a bit of an internal struggle (as seen with last week’s beef and broccoli stir fry recipe , in which I hesitatingly called for a teaspoon of flour as a thickener) because while adding a bit of flour or cornstarch to a larger recipe may not drastically impact the carb count, it does complicate the consistently Primal message I try to convey. This post, I hope, will resolve that struggle.
There are plenty of ways to thicken a sauce without resorting to refined starches. In fact, thickening a sauce using Primal methods can produce a richer, more satisfying meal.
The most rewarding way to thicken a sauce is by reduction. Indeed, learning how to reduce a sauce is important for any cook – home or professional. It’s quite simple, actually, but it’s an integral step in the thickening of any sauce or soup (whether you keep it Primal or use starches). Reduce the moisture content of a potential sauce by simmering over low heat and letting evaporation take over. The water goes, but the flavors stay. If you reduce too much, be prepared for incredibly potent flavors. Adding fats toward the end of the reduction process can complete the thickening process (more later).
Ah, the epic battle between fats and carbohydrates rages on. Fats can make effective thickeners, especially butter and especially with reductions. Say you’ve just seared a garlic-and-shallot-studded steak in your cast-iron pan. See those browned bits and bubbles of delicious beef fat and juices left behind? Keep the heat low and add some red wine. Scrape the good stuff off the bottom and let the wine reduce Toward the end, add a pat of cold butter and whisk it all together until smooth and creamy and viscous. Drizzle over your finished steak and veggies. Mmmm.
Heavy cream works well, too, especially for white sauces and soups. Again, the key is reduce, reduce, reduce.
Rendered duck, bacon, beef, or chicken fat can act like butter, if you want to avoid dairy altogether or add a different flavor profile. Just make sure you add the fat towards the end in its solid (cold) state.
Adding a few scoops of pureed vegetables is another option, especially to thicken soups. Almost any acceptably Primal veggie will work: squash, carrot, broccoli, cauliflower, zucchini, or mushrooms, just to name a few. Simply steam or soften the vegetables and then throw them in a food processor or otherwise pulverize them. Canned tomato paste works well, too. If you’re already cooking a vegetable-filled stew or soup for hours, this might happen on its own as the veggies break down and add density to the broth.
You already know how much we love almond meal  around here, and the other nut meals/flours can work as sauce thickeners. Unlike traditional flours, these don’t really clump when added directly to a sauce, but they can add flavors you might not expect or really want in your sauce, so be careful. You can also use nut butters – a little bit goes a long way.
Vegetable gums sound a bit unappetizing, but they’re used in a lot of Asian cooking. Essentially pure fiber that absorbs moisture to form a gel, the most popular of the vegetable gums are xanthan gum and guar gum. Sprinkle over sauces while whisking to thicken, but be cautious – a little bit goes a long, long way, and too much will make your sauce “gummy” and “gooey” rather than creamy.
Vegetable gums can be a bit tricky to use properly, but there are products that make it easier. I’ve never used ThickenThin Not/Starch Thickener , but it’s touted as an easy-to-use thickener for sauces and soups without any net carbs or impact on taste. It combines guar, xanthan, carob, and acacia gums. There’s a far amount of noise about this stuff in the low-carb community, so I’m interested if anyone’s ever used it.
I’d say reduction is the most purely Primal way to thicken a sauce, but it’s not exactly the quickest or the easiest. It remains my favorite (excepting, of course, the fact that I haven’t tried the gums) because it produces the richest flavors and textures, especially with some sort of animal fat as a thickener. The nut flours work well enough, but the resultant textures will never completely compare to those of traditional flour thickeners; nuts are just too coarse and non-absorbent. Vegetable purees are delicious, nutritious thickeners, but they have limited use (mainly in soups and stews). As for the vegetable gums, I suppose these are technically PB-friendly – they come from natural sources and they’re definitely low-carb – but I’m not sure I’d want to rely on them completely, and I’m skeptical of “low-carb”packaging. Of course, I plan on trying them at some point, and I’d love to hear your experiences with them.
Oh, and for the broccoli beef recipe? I think a vegetable gum would be your best bet. I don’t know how well butter or cream would compliment the flavors, and I doubt nut flours would blend seamlessly into the sauce; with this one, you’re just going for texture alone, and the gums would probably achieve that without compromising flavor or cooking time.