Kava Fact of the Day Heating Kava, viscosity and the role of starch.

[The Kap'n]

Today we’re talking about the starch content of kava, and how that plays into the gelatinization of kavas when heated past the solubility temperature of starch.

There is a well-known tip to never go above 140°F (60°C) when making your kava. Originally, we considered this to be the indication that anything above these temperatures would cause the degradation of kavalactones. This seems not to be the case. The melting point of kavalactones ranges between 248°F (120°C) to 284°F (140°C). The boiling point for kavalactones is even higher at around a theoretical 850°F (~450°C). What this tells us is that when heating kava, we’re likely not to be destroying kavalactones in our brew. So why is it suggested to stay below 140°F (60°C)?

This brings us to our other topic, starch. Dried rootstock of kava consists of about 43% starch depending on the age and cultivar of the plant [1]. This component plays a major role in the thickness or body of the prepared kava drink. Kavas higher in starch amounts will tend to make a smoother, creamier, and thicker beverage. Starch amount rarely plays into issues with making kava, as starch is not water soluble under normal, not heated, conditions. Starch has a temperature range, however, where it begins to absorb water and dissolve in the presence of heat. Consequently, this temperature falls in the 140°F (60°C) – 203°F (95°C) range [2]. This is known as “Starch gelatinization”, and when this happens starch breaks down and begins to act as a binding agent in water. The native starch solubility was negligible (~4 %) in cold water at 77°F (25°C); however, it increased significantly (~23 %) when starch suspension was prepared at 95°F (35°C) [3]. When raw starch is heated in water, the semicrystalline nature of their structure is reduced or eliminated and the starch granules break down, forming a viscous solution [4]. When making kava, to prevent this “gelatinization”, be sure to use room temp or tepid water, and stay under 140°F (60°C).



[1] Fu, Peter P et al. “Toxicity of kava kava.” Journal of environmental science and health. Part C, Environmental carcinogenesis & ecotoxicology reviews vol. 26,1 (2008): 89-112. doi:10.1080/10590500801907407

[2] Lumdubwong, Namfone. “Applications of Starch-Based Films in Food Packaging.” Reference Module in Food Science, Elsevier, 2019. ScienceDirect, doi:10.1016/B978-0-08-100596-5.22481-5.

[3] Jivan, Mehdi Jalali et al. “Preparation of cold water-soluble potato starch and its characterization.” Journal of food science and technology vol. 51,3 (2014): 601-5. doi:10.1007/s13197-013-1200-y

[4] Ratnayake WS, Jackson DS. Starch gelatinization. Adv Food Nutr Res. 2009;55:221-68. doi: 10.1016/S1043-4526(08)00405-1. PMID: 18772106.

 

[Jacob Bula]

I can confirm. When I made mongrel grog with frozen makas by pouring boiling water over them and then straining, I got this gelatinous, tangy mixture. The effects were just fine, especially for a 3rd wash, but it was not very tasty and the texture was gelatinous.

 

[Aloha Kava]

There's a balance I like to achieve. If I heat it enough so that it's slightly thicker, I swear the effects and maybe even the taste are better. But anything slightly over that goldilocks zone becomes a mush that tastes like ashes.

 

[Crunked]

View attachment 11550​

Today we’re talking about the starch content of kava, and how that plays into the gelatinization of kavas when heated past the solubility temperature of starch.

This brings us to our other topic, starch. Dried rootstock of kava consists of about 43% starch depending on the age and cultivar of the plant [1]. This component plays a major role in the thickness or body of the prepared kava drink. Kavas higher in starch amounts will tend to make a smoother, creamier, and thicker beverage. Starch amount rarely plays into issues with making kava, as starch is not water soluble under normal, not heated, conditions. Starch has a temperature range, however, where it begins to absorb water and dissolve in the presence of heat. Consequently, this temperature falls in the 140°F (60°C) – 203°F (95°C) range [2]. This is known as “Starch gelatinization”, and when this happens starch breaks down and begins to act as a binding agent in water. The native starch solubility was negligible (~4 %) in cold water at 77°F (25°C); however, it increased significantly (~23 %) when starch suspension was prepared at 95°F (35°C) [3]. When raw starch is heated in water, the semicrystalline nature of their structure is reduced or eliminated and the starch granules break down, forming a viscous solution [4]. When making kava, to prevent this “gelatinization”, be sure to use room temp or tepid water, and stay under 140°F (60°C).

Very interesting. The only time I have ever been sick after consuming kava was when I tried the heat and eat method. Not only was it far less palatable than usual, my body rejected it. Just seeing that jar of goo in the photo triggered me. Never again.

At least now I know how it became so thick and nauseating. Also interesting from a carb perspective. If starch isn't water soluble at cool temperatures, wouldn't it follow that most of the starch remains in the makas of kava prepared in the traditional way?

 

[kastom_lif]

There's a balance I like to achieve. If I heat it enough so that it's slightly thicker, I swear the effects and maybe even the taste are better. But anything slightly over that goldilocks zone becomes a mush that tastes like ashes.

If you like your grog thicker, try smashing up another plant along with your kava root when you do a traditional prep. Hibiscus bark is what's traditionally used on Pohnpei. Any fresh green nontoxic Malvaceae, like rose mallow, okra, or temperate hibiscus works fine too. Fresh roots of common mullein (verbascum thrapsus) or even fresh liquorice root will also provide plenty of mucilage (which is simply soluble fiber).

Another trick is to dissolve a little bit of kitchen starch (corn starch, arrowroot, potato starch etc) in warm water, then add the starchy water to your mixing bowl.

Sometimes when your makas seems washed, adding extra starch to subsequent washes helps get more kavalactones out.