Our recent post on the optimal number of “washes” explored the question of how much kava/kavalactones you can extract each time you re-use the same room with fresh water when preparing kava the traditional way. Many readers have sent us follow up questions about that research. One of the most common questions was whether or not the amount of time one spends on kneading the kava can impact the strength of the kava. It’s actually one of the most frequently asked questions about kava preparation: how long does one need to knead the bag of kava to get the best return on their efforts? Our our experience suggests that the optimal time is around 5-7 minutes depending on the strength of the kneader, the amount of powder in the bag etc. This amount of time seems to be sufficient to produce a strong and creamy liquid. We’ve always thought that kneading it for longer offered a poor return on the invested time and effort, but had no solid data to back up our subjective view. Now our friends at Root & Pestle have decided to put this question to test and run a series of experiments to determine the kavalactone concentration in kava prepared at different squeeze durations. Some of their results surprised us!

Read their guest post below to find out more:

Maximum extraction per squeeze

57.89% was the maximum kavalactone extraction efficiency we were able to achieve in a single squeeze/wash, regardless of how long we massaged our strainer bag. Chemotypes of the beverages were largely unaffected by squeeze times.

Our lyophilised samples made it abundantly clear that more material had been extracted as squeeze duration increased, but despite the progressively larger amounts of sedimentation, the amount of kavalactones extracted did not continue to increase beyond a certain point.

How long is long enough?

Within just 80 seconds of squeezing (followed by strong handwringing of the strainer bag), we had already extracted an average of over 45% of the available kavalactone content, with extraction efficiencies increasing steadily up until about the 4-and-a-half-minute mark and plateauing shortly thereafter. No squeeze longer than 404 seconds (6.73 minutes) resulted in higher kavalactone concentrations in the resulting beverage, even if we massaged the strainer bag for an hour straight.

Short squeezes lasting only a few minutes gave us potent kava that was very light and easy to drink, even seeming a bit too “watered down” to our seasoned taste testers (who have become accustomed to the rich and creamy kava as served locally in Vanuatu). Longer squeezes made the mixture thicker, becoming more like nakamal style kava around the 7-minute mark and beyond, and giving us the initial subjective perception that we were drinking “seriously strong” kava, but it wasn’t typically any more abundant in kavalactones than squeezes that lasted only 5 minutes.

Experimental Conditions:

These results were based on squeezing 62.5 g of traditional kava powder in an R&P strainer bag in 1 L of 28 °C water, using our automated squeeze system for consistent results. The details of our squeeze and analysis conditions were largely unchanged from those in our multiple wash experiments [as documented in our previous blog post]

30 unique analyses were performed for these squeeze-time trials. While this sample size is relatively small, we feel it was sufficient to identify general trends. Our experiments and analyses are ongoing.

We hope our findings offer valuable insights into your kava preparation. By sharing this data, we aim to support the kava community with reliable, research-based information to enhance everyone's kava experience, but keep in mind that individual tastes vary, and maximising kavalactone extraction efficiency doesn't necessarily mean a method is best for you. Experiment to find your optimal squeeze!

Additional comment from us:

We were surprised to learn it takes so little time to achieve such a high degree of kavalactone extraction (at least one one uses the kind of kava powder we offer through our shop) At the same time, we are quite convinced there’s more to the potency of the kava experience than mere kavalactone concentration. We could be wrong, but believe the other compounds in kava may work in synergy with the kavalactones to enhance the experience, hence still feel that squeezing the kava for a bit longer than 2 minutes may produce better results. In any case it seems that squeezing for longer than 7 minutes is almost certainly not worth it, so our original recommendation, born out of years of experience, to squeeze kava for 5-7 minutes still seems quite reasonable. For those who find the process too time-consuming though we might suggest a slightly shorter squeeze time from now on, knowing that even 2-3 minutes of squeezing should produce a potent drink.