how-to Archives • Katie's Tropical Kitchen

We are super lucky to have such an abundant fruit farm – but MAN! it is a lot of work to figure out how when to harvest, how to process and how to store the large variety of fruit we have. I’m writing this how-to guide on processing macadamia nuts at home as I’m dealing with my second annual harvest from a tree that was planted on the farm by the previous owners. It just started to produce last year (my 6th year here). So I’m guessing our tree is about 13 years old now. Another fun fact about mac nut trees, they self pollinate (almost all varieties at least), so you only need one to get a good fruit set.

Unlike many of my tropical culinary projects, this one may actually be worth the time considering how much macadamia nuts cost in the stores, even in Hawaii. Cassava flour on the other hand… that DYI is a labor of love. For me macadamia nut season is a time when I get to cozy up in the kitchen, put on my new favorite Spanish-Language series and crack nuts all night long.

5 from 1 vote

How to process macadamia nuts at home

Course: Ingredient preparation

Keyword: macadamia nuts

Calories:

Author: katiestropicalkitchen

Equipment

Macadamia nut cracker
Trays with holes, baking sheets
Dehydrator
Oven

Materials

freshly havested macadamia nuts

Instructions

Harvesting Macadamia Nuts

Your macadamia nuts will drop from the tree when they are ready to harvest.
For ease in harvesting, it is good to mow around the tree on the highest setting regularly. Or, if your tree is an a shadded area with a lot of leaf drop, you can use a leaf blower to seperate the leaves from the shells.
I like to harvest them from the ground every 2-3 days, but you can let them sit as long as a week.

Husking the macadamia nuts

It is important to husk the macadamia nuts soon after harvesting them about 24 hours. This is because if left in their shell with poor oxygen flow, it will cause mold and make the husks harder to remove, increasing processing time. But, if more time goes by, you can still harvest, remove the half cracked husks, and we like to recommend a thorough cleaning of any mold in warm water first and then food grade hydrogen peroxide.
To husk them, I use my macadamia nut cracker. It usually takes one or 2 cracks to remove the husks. Place them on your drying racks.
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Drying the macadamia nuts

If you have ever tried cracking a mac nut right away you will notice they stick to the shell and they sort of taste like coconut. To get that fatty macadamia nut you crave, you need to reduce the initial moisture content of the macadamia by airdrying it for 2-3 weeks. This can be done in a place that is out of direct sunlight and gets decent airflow. I like to dry ours on our screened in porches. I have the best results using trays with holes on the bottom. Specifically, I use trays from a previous dehydrator we had that broke. They are perfect for enhancing airflow and containing the nuts. I use a china marker to date the trays for easy tracking. Every few days I roll them around a little to get airflow to the different sides.
After the initial air drying, you will notice the nuts are more easily removed from the shell but parts still stick. You will also notice a change in color. Pictured to the bottom are mac nuts that have been air-dried about 3 weeks versus the picture on the top only a few days. Now, you need to dry them further at a higher temperature. This is best done in your dehydrator on a low "nut" setting of about 104° F for about 2 days.
I find my Ivation dehydrator is actually perfect for this. The nuts fit perfecting into the wire mesh drying sheets. If you have extra space – evenly space out the trays so all the nuts get a lots of air.
About 2 times a day it is good to roll them around a little to change their position. After 2 days you can increase the temperature to 130-150° F and check them every couple hours until the shell is very brittle and cracks easily. When the mac nut is perfectly done you can hear it rattle around inside the shell.
If you do not have a dehydrator, you can also use your oven on the lowest setting (mine is 170° F). But they will dry much quicker, which is not necessarily better. If they dry too quick, they may dry unevenly, change color, and they are prone to getting a brown, tough spot in the middle of the nut. This is the case especially when they are roasted and can result in a less desirable taste.

Cracking & storing the macadamia nuts

Once they are uniformly dry, cozy up and start the final cracking.
The raw macadamia nuts can be kept in an air tight container, but they are best stored in the fridge or freezer. You will also benefit from vacuum sealing them for prolonged life.

Roasting the macadamia nuts

You can roast them in the oven on about 275° F for 20-30 minutes, best done on wire mesh baking sheets (like the ones in my dehydrator). If you want them salted toss them in a small amount of oil and salt.

Notes

Resources:

http://www.macnuts.org/growpage.htm

Cassava is an excellent starch for the tropical diet. And making homemade cassava flour is a great way to store your crop with minimal space. My husband has been trying to grow cassava on our tropical fruit farm on Big Island for 6 years. But, every time the cassava is ready to harvest the wild boars come dig it up and eat it. Finally, we started planting cassava in our large garden protected by electric netting. This is the first year we have had multiple harvests. It takes a minimum of 6-7 months for smaller roots and for some varieties up to 24 months to harvest. Cassava grows readily from cuttings. If you are in Hawaiʻi and are interested in cassava cuttings, contact me or visit our farm website ainaexotics.com.

How to reduce cyanide in raw cassava

Most how-to recipes for homemade cassava flour tell you to cook cassava pieces first and then grate them. I think this is quite silly. The authors may be worried about cyanogenic compounds (cyanide) in cassava. But if you ever cooked cassava you know it becomes starchy and sticky, and very hard to grate.

There several methods to reduce the cyanogenic compounds (cyanide) in cassava. If you eat these compounds raw they have a toxic effect. There are also varieties with low cyanogenic compounds. One method of reduction is cooking by boiling, steaming or baking. Soaking the cassava in water also reduces the cyanide. Industrial producers of cassava flour rely on the drying and milling process to reduce cyanide levels. In the more traditional version of cassava flour, they ferment the grated cassava to reduce it’s toxicity, and then dry.

Gari – a fermented cassava flour / granules

There is similar product to milled cassava flour, called Gari. Gari is staple in West Africa, in particular Nigeria which is the leading industrial producer of cassava flour. There, they grate Gari and ferment it for 3-7 days. Then they roast it and sift it into cassava granules. Their goal is to achieve a slightly fermented and sour taste while assuring that the cyanogenic compounds are decreased. West Africans use Gari as a side dish, a thickener, and as an ingredient on other dishes, desserts and more.

My method for making homemade cassava flour

This tutorial gives you a few extra steps to reduce the cyanogenic compounds in case you would like to be on the safer side. These steps are optional but if you have the time, they can enhance the quality of the flour. Basically, I soak the peeled cassava in water and hang/slightly fermenting it overnight or up to 24 hours before drying. As I am writing this I have 13 pounds of shredded cassava that have been hanging from my bathtub curtain rod for 24 hours. I actually find the smell really pleasing, sort of nutty.

This is basically a 2-3 day process depending on how much cassava you are processing, if you decide to ferment (and length of ferment) and what time in the day you start. I started with probably 20 pounds of freshly harvested yucca. It took me about and 1 1/2 to peel, core and grate the cassava. Then I hung the cassava in a mesh bag for 24 hours. My drying process took 8-10 hours and by that time it was bed time. Consequently, I kept the pilot light of my oven on to prevent it from re-hydrating or molding, and I “milled” it the next day.

Here is a few more tips:

You are better off processing cassava fresh, within 2-3 days of harvesting. I processed some of the left over cassava on day 4 and there was noticeable deterioration of the root, it started to become streaked, sort of blue and in some cases there was evidence of rot. Also, the ends of the roots which weren’t tapered and clean cut had started to mold.

You can peel and wash and leave in soaked water for a few days in the fridge if you are not ready to deal with the grating or processing.

The knife pictured below is hardly big enough to process really thick roots. For those I use a really heavy duty butchers knife / cleaver.

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