Blackberry custard pie features an easy buttermilk custard pie filling in a pre-baked pie crust with fresh blackberries. This no-bake pie recipe cooks in minutes and is sugar-free for low carb diets.
(Maybe you’ve noticed small animal figures in some my photos. This is to honor my mother who is suffering from autoimmune disease. I love you mama.)
This blackberry custard pie hearkens back to my childhood when I spent summers with red-stained fingers and scratched hands from picking wild blackberries and raspberries in the woods in upstate NY. My Nana taught me how to make traditional 2-crust berry pies and also shared her recipe for my favorite custard pie!
Blackberry Custard Pie
If you poke around the site for any length of time you’ll get a sense that I love steak, share mostly chicken recipes and have a fair amount of low carb and sugar-free pie recipes. What can I say? My husband loves pie and I like to make ‘em – especially old fashioned favorites from my childhood like this sugar-free blackberry custard pie.
Buttermilk pie is an old fashioned pie recipe, especially popular in the southern part of the U.S. The buttermilk custard is thickened with flour while the similar chess pie uses cornmeal. It’s a simple pie with gorgeous flavor that has graced many Southern tables over the years. Custard pies are sophisticated in their simplicity, like a classic creme brulee; eggs, sugar and cream (or milk) bake in a crust until the custard sets. The texture is amazingly smooth and creamy when cooked correctly, but if baked too long… disaster!
I have fond memories of the old fashioned custard pies my grandmother made with blackberries, blueberries and sometimes red currants. Having a slice of creamy custard pie was the best way to enjoy the “fruits” of my labor after picking wild berries all afternoon. It feels good to share a similar recipe with my family – like I’m doing my part to pass-down family food traditions.
Custard Pie and Easy Buttermilk Pie
I worked on this sugar-free blackberry custard pie recipe all Spring and Summer. It proved to be a little trickier than expected. The buttermilk custard was sublime and perfect every time, but the low carb pie crust burned before the custard set. It didn’t matter what I tried, the crust always over-browned. Our low carb almond flour crusts are delicious and nutritious, but they are sometimes tricky.
As I mentioned, timing was an issue with this pie, so I decided to cook the custard on the stove like a pudding filling. Adding a little gelatin provided the perfect texture and a low carb sugar substitute (Tagatesse) sweetened it beautifully. I simply poured the sugar-free custard into the pie crust and added the blackberries to the top. Leaving the pie uncovered in the fridge helped the custard develop a skin which was perfect for torching (an optional step). This gave an overall “baked” look to the pie and caramelization to the blackberries.
If you’ve never cooked a custard on the stove before, don’t worry. Like my other sugar-free custard and pudding recipes, it takes 10 minutes tops! For added security, you can use a double boiler method – the extra time is worth it for some. Using a pre-baked pie crust will have the pie finished and chilling in under 30 minutes.
This is a delicious pie for Spring and Summer, or anytime you can find fresh blackberries.
Blackberry Custard Pie is 6 net carbs per serving.
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Blackberry Custard Pie - Easy Buttermilk Pie Recipe (Sugar-free, Low Carb)
Ingredients
- 1 recipe Low Carb Keto Graham Cracker Crust (resists soaking) or your favorite 9-inch pie crust recipe)
- 1 cup buttermilk
- 3/4 cup heavy cream
- 1/2 cup low carb sugar
- 1/4 tsp xanthan gum
- 4 large eggs
- 2 large egg yolks
- 1 tsp gelatin powder (bloomed in 1 tbsp water)
- 1 tsp vanilla extract
- 1 pinch salt
- 1 pinch ground nutmeg
- 1 cup blackberries (1/2 pint)
Instructions
Preparation
- Sprinkle gelatin over 1 tablespoon water to bloom. Measure sweetener, salt and xanthan gum in a 4-6 cup capacity non-reactive metal pot. Add the eggs and yolks and whisk together until completely combined. Whisk in the buttermilk and heavy cream.
Cook
- Place the pot over medium heat, whisking constantly until the mixture begins to thicken - about the 5 minute mark if using Tagatesse (or sugar) and 8 minutes for Sukrin :1 or Swerve. Turn the heat down to medium low and whisk vigorously for 1 minute. (The custard should bubble lazily if whisking stops.) Remove from heat and whisk for 1 1/2 minutes more. Tear the gelatin into pieces and drop into the custard, stirring until dissolved. Add vanilla and nutmeg, stirring to blend.
Assemble
- Let the mixture cool just slightly then pour into pre-baked pie crust. Level the top and arrange black berries, pushing them into the custard until they are at least 1/2 way submerged. Refrigerate uncovered for several hours before covering with cling film. Chill at least 6 hours before slicing and serving.
Optional Step
- Sprinkle Tagatessse [Sukrin Melis, Swerve Confectioners (or powdered sugar if not low carb)] over the top and brown with a culinary torch. Pay particular attention to the black berries to make them look like they baked.
Serves 8. Each serving is 5 g NET CARBS. Nutritional information includes the crust specified and linked to.
Notes
Nutrition
Nana’s Cheese Pie – Crustless Cheesecake Recipe (low carb, sugar-free)
Black Bottom Pie (Low Carb, Sugar-free)
Hello Kim, thank you for all your recipes. I would really like to try this recipe but I can’t get buttermilk where I am. Do you know if I can substitute it with something else? Thank you very much
Hi Dora. Yes, use 2/3 cup heavy cream, 1/4 cup water and 2 tbsp fresh lemon juice. Let it sit together to clabber (separate and “break” and get chunky-ish) before using. Enjoy the recipe. -Kim
Did i miss the recipe for the low carb graham cracker crust? Please and thank you!
No, you didn’t miss it Mindy. It wasn’t linked. I’ve fixed the problem. This is a great pie. I hope you enjoy it. -Kim
About to start the recipe. Someone commented they used 1/2 cup erythritol and it was bitter. I’m
nervous. So how much Stevia should I add to avoid bitter.
Hi Syliva. Erythritol is not bitter, stevia is. Some people are super tasters and many of the erythritol blends contain stevia – and stevia can take some getting used to. Perhaps that person tasted the stevia in the sweetener blend or perhaps they used liquid stevia, which I find to be very bitter. That is why I recommend to use smaller amounts of erythritol blends and to augment sweetness with stevia glycerite (not bitter). Use what sweetener you have to taste. -Kim
I am allergic to mammal foods which includes gelatin. Is there any substitute that you can recommend?
Sue are you asking for a diary-free and gelatin free version of this pie? -Kim
I quickly did a Google search about agar (substitute agar for gelatin). It is 8 times more powerful than gelatin and must be dissolved in liquid before using. You could probably use it and coconut milk if you are allergic to mammal food. I have not tested agar in this recipe and do not know how much you will need. -Kim
Hello,Kim.
You website is my favorite for low carb recipes. Thanks
I never bought buttermilk. What brand do you buy in USA?
Thanks
Great question, Mari. My store carries Knudsen. I think it is lower fat, but that’s all I can find. I have several recipes that call for buttermilk, so it won’t go to waste. Enjoy the recipe. -Kim
Did I miss the measurement for the blackberries? Did you just eyeball an amount that fits in the pie?
Hi Kelly. Thank you SO MUCH for letting me know the recipe was missing blackberries from the ingredients! I added them in and recalculated the nutritional information on a better nutritional calculator (Fatsecret.com). This is such a nice recipe. I hope you enjoy it. -Kim
Years ago I read a recommendation by (I think) Adele Davis to bake the crust and the custard for a custard pie in separate pie plates and then slide the custard into the crust. Your way is probably easier.
Hi Barb. I tried the “slip-slide” custard recipe many times and couldn’t get it to work reliably. I felt that this was easier, although a little softer custard than that recipe. This is foolproof (if one doesn’t overcook the eggs) and much easier. There is a recipe for “slip-slide” custard in the original Better Homes and Gardens Cookbook (the red one). It is still available in print. -Kim
I brought this pie to my in-laws and it was devoured. Everyone kept raving! I am not low carb so I used a regular pre-baked pie crust and sugar in the recipe. It was easy to make and very, very good. Thank you!
Great! I’m glad found the recipe and were able to follow my suggestions. It’s always good karma points to impress the in-laws. Lol. Have a great weekend. -Kim
This custard pie was very good. It was easy to put together and looked like the picture – I did not brown the top because I did not have a torch. Thanks for a great recipe!
Oh, good. I’m glad you found the recipe to be easy and tasty. Thanks for leaving a comment and rating. Have a great day. -Kim
What does :1or Swerve mean? How much Swerve or erythritol? Thanks
Hi Babs. Sukrin :1 is an erythritol based sweetener like Swerve. The recipe says to use 1/2 cup. If you are using regular erythritol use 1/2 cup and augment sweetness with a little Stevia. Adding more erythritol may result in it crystallizing after a day or two. Thanks for your question and have a nice day. -Kim
Thanks for your reply Kim. I was in the middle of making the recipe yesterday when I realized I didn’t know what that meant so I put in 1 cup of your erythritol and as you can imagine it’s a little bit bitter. I also added a little stevia because I had no idea what I was doing. :) The crust is awesome!! Thanks for your help.
Oof! It will be better next time. You are very welcome. It’s all a little strange just staring out. Enjoy your day. -Kim
This looks so incredibly delicious and perfect for late summer! I’m wondering – I don’t keep xathan gum in the house. Could I substitute in another thickener, like cornstarch – and would you be able to advice what might be a decent conversion? All of google’s suggestions are geared toward gluten-free cooking, but gluten is just fine in our household.
Thank you, Kabe. Yes, I would use 1 tsp of cornstarch to sub for the xanthan gum. I don’t sweeten my baked goods as much as others so you may need to taste as you go. Have a wonderful week and enjoy the recipe. -Kim
Oh! This pie looks good!
Thanks so much, Bethany. It was a real treat to test this recipe. Enjoy your week! -Kim
Hello, I have three questions: can I use soy protein powder in the pie crust recipe instead of whey? And is there something I can use instead of erythritol? Lastly, I have something called Nu-Naturals More Fiber Stevia Baking Blend Premium Sweetener”. Can I use this for the sweetener in the pie?
Oops, one more! What is the sauce in your photos of the broccoli fritters?
Thanks,
Addie p.s. I didn’t rate the recipe because I haven’t made it yet, but it looks yummy!
Hi Addie. I have never used soy protein powder so I don’t know. I would guess, yes? The reason I have included the whey protein powder in the recipe is because it helps give it a graham cracker consistency. Instead of the erythritol, use you favorite non-liquid low carb sweetener. I have heard that Nu-Naturals is a good one. The sauce in the broccoli fritters photo is just a simple Remoulade sauce. You can find a million recipes for Remoulade sauce on Google. I hope you enjoy the recipe and have a nice weekend. -Kim
Thanks so much for answering my questions; i’m afraid I have some more…
Can I freeze the broccoli and/or cauliflower fritters? And do you have a favorite remoulade recipe?
Cheers,
Addie
Yes, Addie. The fritters can be frozen. Just put a piece of waxed paper between each fritter and place in a Zip-loc bag. Thaw in the freezer. Crisp/heat up in a pan for best texture, but you can also reheat in the microwave. Simply Recipes always has good recipes. Try her Remoulade Sauce Recipe. Cheers, to you! -Kim
Ok, thank you Kim, I’ll check it out. I think I’ll thaw the fritters in the fridge, though LOL
Cheers,
Addie
Oops! I’m usually more careful to check info before commenting, but just saw the totals, too–thx
No problem, TeeDee. It means that something wasn’t clear, so I am glad you let me know I need to reword it. I used the bold text in my reply just in case someone else had the same question. Thanks again so much for your question. Enjoy your day. -Kim
Why would there only be nutritional info for the filling, when it is a pie? Do you have the total calorie and carb counts for this?
TeeDee, the nutritional information listed is combined with the crust linked to in the ingredients. As a courtesy, I also included the nutritional information for the filling only in case someone wanted to use their own crust. I will try to make that more clear. I hope I have answered your question. Please let me know if you have any others. Enjoy the pie. -Kim
Is this pie firm enough to go crustless?
Yes, Kirsten. It might even be nice in ramekins. With blackberries on top. It’s very nice. Enjoy. -Kim