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16 Mar

Dear Mark: Low-Carb Sauce Thickeners

Dear Mark,

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.

Pureed Veggies

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.

Primal Flours

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.

I’ve heard good things about defatted coconut flour. Never used it myself, but it is an effectively low-carb (high in fiber, though). Anyone tried coconut flour?

Vegetable Gums

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.

Further Reading:

How to Make Dried Fruit

Egg Purchasing Guide

When it Comes to Fat, How Hot is Too Hot?

You want comments? We got comments:

Imagine you’re George Clooney. Take a moment to admire your grooming and wit. Okay, now imagine someone walks up to you and asks, “What’s your name?” You say, “I’m George Clooney.” Or maybe you say, “I’m the Clooninator!” You don’t say “I’m George of George Clooney Sells Movies Blog” and you certainly don’t say, “I’m Clooney Weight Loss Plan”. So while spam is technically meat, it ain’t anywhere near Primal. Please nickname yourself something your friends would call you.

  1. I have been struggling with thickening sauces for a while now. Thank you for all of this info. I am goning to give coconut flour a whirl I think and see how that goes.

    The SoG

    Son of Grok wrote on March 16th, 2009
    • Are you hip to COCONUT CREAM? It’s gluten-free, low-carb & a great thickener for almost any dish. Not to be confused with that awful, canned sludge used to make yucky blender drinks, Coconut Cream is made by mixing fresh, shredded coconut meat with hot water, the squeezing out the water. After 2 years of spending a pretty penny for a fancy ‘coconut cream concentrate’ from Tropical Traditions (a good quality product but it’s too dry & hard to work with, IMO), I had to start cutting corners in my grocery budget in order to keep buying grassfed beef. So I went old-school, found a Carribean grocery store (which is acutally owned by Koreans) & went back to buying CKI PURE CREAMED COCONUT. Imported from Sri Lanka, a 6 oz. (170gm) block sells for 99 cents. (There’s NOTHING healthy you can buy to eat in American for 99 cents anymore!) Look for the red box with blue & white lettering. Open it up, remove the blue outer wrapping & the block of coconut cream will be inside the second clear plastic wrapping. Along the edge of the block you’ll find a layer of pure coconut oil (assuming it’s been kept below room temp). Coconut products (except fresh coconut milk) don’t spoil, but during warm weather, you’ll want to store coconut cream in the fridge to keep the oil from leaking. If you snip off the corner of the wrapper, you can squeeze out the coconut oil & use it for something else. What you’ll have left will be dense, thick, slightly sweet coconut cream.

      A Tbsp. of coconut cream mixed with half a cup of hot water (he way you’d make a slurry) & added to stock or soup will thicken a large bowl of whatever you’re cooking. Use a whisk to blend coconut cream slurry into sauces to give them a silky texture. For you dairy-free folks, a bit of coconut cream whisked into tomato soup gives it the that richness & sheen you normally get from adding butter right before serving. The coconut cream’s natural sweetness tames the acidicty of tomato soup or sauce just enough. As for the numbers:
      Serving size: 1oz
      Servings per containe (box): 6
      Calories: 200
      Calories from fat: 170
      Total fat: 19gm
      Saturated fat: 14gm
      Cholesterol: 0mg
      Sodium: 10mg
      Total Carbs: 2gm
      Dietary fibre: 1gm
      Protein: 3gm
      Natural sucrose: 2gm

      – RC

      RC wrote on March 22nd, 2011
    • Love coconut flour for baking but it doesn’t thicken sauces.

      Rosana wrote on March 3rd, 2013
  2. I use Arrowroot to thicken sauces. You can find it by the spices at the grocery store. It works much like corn starch. I mix a teaspoon or so with a little bit of cold water (to reduce clumping), and then put it in whatever I’m making.

    I try to use the reduction method as well, but am way too impatient.

    Mary wrote on March 16th, 2009
    • Arrow root also freezes well, unlike corn starch. It thickens about the same and gives the same velvety sheen to the sauce.

      Eric wrote on March 21st, 2010
  3. I use konjac flour. Carb free, calorie free, gluten free and high in soluble fiber. Works better than cornstarch, has no taste of its own, so takes on the taste of whatever it’s stirred into. What more could one ask for?

    Ailu wrote on March 16th, 2009
  4. Xanthan gum come from metabolism of corn sugars by the bacteia Xanthomonas. So not strictly plant based. The end product is a film/goo produced by the bacteria.

    Anyway, I use Xgum a lot. Be careful people, you need A LOT LESS than you would think to thicken sauces and soups. A teaspoon would do for a big pot of soup! Just mix it in a jar and poor it in like you would cornstarch (so it does not clump). Its great for hot and cold things too, and neednt boil to be effective. I love it.

    Tara wrote on March 16th, 2009
    • I have tried xgum for thickening and can’t dissolve it in water, watch the trick?

      Rosana wrote on March 3rd, 2013
  5. Did I mention I cant type, at all? Yeesh.

    Tara wrote on March 16th, 2009
  6. Egg yolk?

    Sarah wrote on March 16th, 2009
  7. SoG – Yeah, let me know. I’m curious to find out how it works for you.

    Mark Sisson wrote on March 16th, 2009
  8. So it looks like Arrowroot and Konjac flour are some good alternatives as well. Thanks, Mary/Ailu!

    Mark Sisson wrote on March 16th, 2009
  9. Egg yolks work really well, used them for years! This is a really old trick. My grandma learned it from her ma, etc.

    bazzta wrote on March 16th, 2009
  10. A subject near and dear to my heart. I typically thicken 2-3 sauses per week and have become pretty adept at it.

    I agree with Mark: reduction is the best way to go, but caution: this adds two levels of added difficulty which you’ll easily manage with experience:

    1. Quantity. You need to get good at having enough to go around once reduced to desired consistency. It may surprise you.

    2. Time. It can often take a lot longer than you think. I like to get my sauces started way before anything else. If you get done ahead of time, just cover and let sit off heat and then touch it up a medium a few minutes before serving.

    Here’s a couple of other thickeners I use with regularity:

    1. Full fat coconut milk. Thai curries are mostly coconut milk and they require very little reduction, if any. It’s got your fat & fiber backed right into the cake. Ready to go. And, if you use the right spices and flavors, it does not come out tasting like coconut.

    2. Crushed blueberries and cranberries. Now, depending on the amount you use, this will impart a flavor. But, let me tell you: just try it on a roast. Tri tip is particularly great. You can experiment with leaving in the fruit skins and with straining through a wire mesh. I do both.

    Oh, and sour cream is a good alternative.

    Careful about using bullion or demi glace and such as your starter stock. Most of them have some wheat (often labelled as roux — which is butter and flour).

    Finally, save all your bones, scraps of meat, and vegetable ends and scraps (even the outside brown skin of onions). Put ’em in a big bag in the freezer and when full, dump it all into a crock pot with a teaspoon or two of vinegar, and let it go for 24 hours. Once the vegetables are soft, mash them up. This gets their starches out. Strain it, and I use a combination of ice trays, silicon cupcake trays, and ziplock plastic ware to store various sizes in the freezer.

    The smaller ones I use for sauces for steaks for the wife & I. A couple of the cupcake sizes makes for a good soup base, and the larger ones do a great job for braising some meat for chili or stew.

    Once you start making your own stock, you’ll never go back and you’ll be forever houding people to save their bones and meat scraps for you.

    Some of my sauce (and chili and stew) exploits can be seen in my “Food Porn” category.

    Richard Nikoley wrote on March 16th, 2009
  11. Awesome tips and suggestions, Richard. Thank you for sharing your wealth of experience on MDA. (BTW – the site redesign is just about complete, and (this is the first time I’ve mentioned this publicly) the new site WILL have a forum, so I hope I can count on you chiming in from time to time. Your comments are always appreciated. Cheers!

    Mark Sisson wrote on March 16th, 2009
  12. Why no mention of arrowroot? It’s great, it works mostly like cornstarch without ANY flavor change, and you don’t need to have the sauce wicked hot to use it.
    I’ve only baked with coconut flour, and from that experience I would say don’t use it for thickening!

    Eva wrote on March 16th, 2009
  13. Coconut flour for me was a definate no no, I tried to thicken gravy with it and while it worked it had a weird texture. Just my two cents :)

    Michelle wrote on March 16th, 2009
  14. Thanks, Eva and Michelle. So it’s a no-go on coconut flour! You might want to take heed, SoG.

    Mark Sisson wrote on March 16th, 2009
  15. The coconut milk works wonderfully. It will be the consistency of a Thai curry dish and you can get it less or more thick, easily. No lumps, clumps, or weird consistency.

    Here’s a tip for a great sauce for roasts. Start with your beef stock, then add about 1/2 tsp each of rosemary and sage (a little less sage is fine — some people are really sensitive to the taste), savory also, if you like, 2 cloves crushed & chopped garlic, and then for the finale: 1/3 to a full small fresh jalapeno pepper, chopped finely, with the seeds. I suggest chop the whole thing, add at least 1/3, then taste after 10 minutes or so, keeping in mind it will likely weaken even with the reduction, and it’s going to be eaten with a roast (I do it with steak, too). Reduce or add in some coconut milk (tbsp at a time), or do both.

    With practice, you’ll be amazed. This is by far my most popular sauce. I’ve tried it with the red chili seeds and though it’s OK, there’s nothing like the fresh jalapeno. Goes with all beef; steaks, roasts, baked or grilled.

    Good luck, all.

    Richard Nikoley wrote on March 16th, 2009
  16. I’ve used the Xanthan gum a number of times and have gotten used to it. Definitely need to watch the amount and it can be gel-like. I need to plan ahead better and work on the reductions.

    Sometimes though its just easier to use a tablespoon of flour or cornstarch. Falls into the 5% of my diet that’s not good. The other 4% being whiskey…

    Joe Matasic wrote on March 16th, 2009
  17. My favorite low-carb thickener is ThickenThin not/Starch. I found pure xanthan gum to be too slimy and coconut fiber too gritty.

    Sometimes I make a quick barbecue sauce for venison steak by deglazing the pan with authentic Japanese mirin (sweet rice wine) and adding chipotle pepper powder. In this case, the chipotle acts as a thickener.

    Alex wrote on March 16th, 2009
  18. Coconut flour works well if you miss baked goods. You can use it to make all sorts of quick breads that have pretty decent textures — muffins, pancakes, etc. But it’s not a good thickener at all.

    I personally use a combination of arrowroot powder & reduction for most sauces.

    And I second Richard’s advice about making your own stock. If you slow cook it for 24-48 hours, it’s incredibly nutrient dense as all the minerals and vitamins leach out of the marrow in the bones.

    I would only add that it’s REALLY important to make stock from bones from grass-fed/pastured/wild animals. Antibiotics, toxins, and hormones are all concentrated and stored in the fats & marrow of animals (including us), so you don’t want to make a stock from unclean animals.

    (AKA FoodRenegade)

    FoodRenegade wrote on March 16th, 2009
  19. I think FoodRenegade is correct about the coconut flour. It’s great for adding coconut flavor and can serve other purposes, but not very useful as a thickening agent (after all it’s just tiny shavings of coconut that are hardly more absorbant than a nut flour).

    Her recommended combo of arrowroot flour and reduction is probably the best advice. That darn arrowroot’s so expensive you gotta make it stretch.

    Mike S wrote on March 16th, 2009
  20. Yea, I’ll chime in too– coconut flour does not work well as a thickener.

    A forum?!? Woohoo! Yippee!

    Ellen wrote on March 17th, 2009
  21. Mark- when are you unveiling the new site?

    Ellen wrote on March 17th, 2009
  22. If you like the taste, flax meal works very, very well.

    Mark, I think you let the cat out of the bag too early.

    Zen Frittata wrote on March 17th, 2009
  23. Hello, I’ve been reading your blog for a few months. It’s very informative and I appreciate all your hard work to bring us this information.

    Regarding the arrowroot being so expensive. It is very expensive purchased in small jars in the spice section. If you have a Whole Foods type store that sells in bulk it is much cheaper.


    Sara E. wrote on March 17th, 2009
  24. Ellen –

    I hope to unveil the new site in the next few weeks. It will have just about every feature readers asked for back in September and then some. The book will be hot on the heels of the site’s release. Thanks for asking!

    Mark Sisson wrote on March 17th, 2009
  25. Less water is definitely a great way to thicken sauce. When i make a soup with meat,veggies, tomato paste works so well to thicken it up. I always cook my soups with V-8 and no water, adding tomato paste just gives it a bold taste, which i like.

    Donna wrote on March 17th, 2009
  26. useful post for those of us with wheat intolerance!

    Danielle T wrote on March 17th, 2009
  27. Gelatin,

    Next time you are making a meat flavoured sauce throw in some bones and let them stew. the gelatin will thicken (its a protein as well) and the bone will enrichen the sauce

    Paul E wrote on March 18th, 2009
  28. I think the coconut flour works fine but I make a roux out of it. My mum used to do this to thicken stews, casseroles all the time. She would always add paprika spice to it aswell. (You don’t have to add paprika).

    Sue wrote on March 18th, 2009
  29. Another vote for xanthan gum! I just blogged about thickening chocolate pudding with it. Going to link back to the post, Mark!

    Lauren B wrote on March 18th, 2009
  30. Great ideas all! Yes xanthan gum needs treating with respect, the result can resemble anything from recycled spittle to Araldite.

    Good points about the peanut butter and coconut also, especially Thai-type recipes benefit: I get blocks of “creamed coconut” or solidified coconut milk which I grate up and which go well with hot chillies.

    Be careful when buying duck fat, mispronounce it and you can get ejected from the shop . . .

    Trinkwasser wrote on March 20th, 2009
  31. I thicken sauces in my crockpot recipes with a little guar gum, puddings with glucomannan powder (Konjac flour) or chia seeds, and cook with coconut flour, flaxmeal, nut meals, and chia seeds.

    Thankfully, there are a lot of very low carb things we can sub for grains. I’m a diabetic and my BGLs won’t handle them.

    DAR wrote on March 21st, 2009
  32. Kuzu root also works as a thickener agent. Kuzu root is made from kudzu and look like white clumpy powder. It is imported from Japan, I believe. It can be used to thicken like arrowroot and also has healing properties – it is alkalizing to the body.

    There is a great anti-stress formula that combines 2 tbsp kuzu, 1 cup apple juice (i know, not primal), and a smidge of vanilla extract. cook until thickened, stirring all the time. Swirl in 1 tbsp of tahini (primal!) and eat hot or cold. This may fall into the category of a decent vice, but it’s great after a tough day.

    Jane wrote on March 26th, 2009
  33. Homemade stock, reduced, is a great thickener, and it’s very mineral-rich, plus the gelatin is very soothing on the digestive tract. It’s a great source of easily digestible calcium, plus the other minerals that have leached out of the bones.

    Tanya Lopez wrote on March 31st, 2009
  34. ThickenThin not/Starch is a great product! Easy to use with great results. However, there are no instructions as far as how much to use in relation to the amount of liquid you have and how thick you want to get it so go easy and just add a bit at a time until you get the results you want. You also do not have to mix it with water first…you can just sprinkle on any liquid hot or cold.

    Cherie wrote on August 22nd, 2009
  35. Okra. Yeah, I know. Slimy, right? I spent 40 years arguing with my Dad about how disgusting Okra was, only to find out that I actually liked it. And if you slice it think (1/4 in) and add a small amount (like 1/4 cup to a 2 quart dish), it thickens very nicely. I tried it in my Thai green curry recipe and it was really wonderful. The flavor just seems to support and enrich the base flavor of the sauce and it thickens without simmering for an hour.

    Ann Coleman wrote on November 9th, 2009
  36. Extremely helpful post and comments. I have just starting thinking about reducing carbs in my cooking. One of my first questions was what to use in place of corn starch… luckily I love coconut milk. Arrow root sounds interesting so I will look for that where I buy my bulk goods. This week I will also be making my first chicken stock. I love the idea of freezing it and using to prepare future sauces, Thanks Richard :)

    Zibi wrote on March 22nd, 2010
  37. I’m surprised that no one mentioned agar-agar. It is a common vegetarian alternative to gelatin, but it can be purchased in flake and powder forms and used to thicken soups, gelatins (Jell-O alternative?), jellies (homemade jellies with fresh fruit or alternative sweeteners, anyone?), and ice creams (probably great for non-custard ice creams that use minimal or artificial sweeteners).
    It comes from red algae, is almost 80% fiber, has a small amount of protein, and supplies a significant amount of iodine. The amount of thickening power depends on the amount of of agar added, but I’ve cooked with it, and I found it very easy to work with and very effective as a sauce thickener.

    VP wrote on April 3rd, 2010

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