Summer Harvest of 2022: Culinary Uses and Nutritional Benefits of Hawaii's Grapes
When you have time check out our two latest short Summer grape videos on our youtube channel. "Picking Summer Grapes" and "Under the Tamiami." at https://www.youtube.com/channel/UC6-o3FGhEOpMSYf4NVlXRIw?app=desktop
This summer was the first year that our grape vines set a good quantity of fruit so that we could taste them and experiment with making juices and raisins, eating out of hand, freezing and making jelly. Before sharing our culinary adventures it is important to reemphasize a few important steps to good production.
After you set out your vine it will take at least three years to see any production. Remember grapes grow very vigorously in the subtropics, and will need to be pruned yearly for good grape production. After experimenting with various amounts of pruning, Gerry found that pruning back 98% of the vine yearly allowed the plant to put more energy into flowering and grape production instead of vine and leaf growth. In the first few years you may need to go under the vine and clip off flower clusters that are misplaced, small, or have other defects. Sometimes he would remove 40-50% of the flower clusters. This seems to increase and improve production, quality, size and taste.
Because we had a small amount of grapes to process this summer, (282 clusters) we used processing equipment that we had in our kitchen for making juice, raisins, jelly, and frozen. This year, did not try making any wine or vinegar but could have. The information below is a short summary of our first attempts at processing various varieties and hopefully will be a beginning guideline for you to do your own experimenting.
Fruit Juice: We had enough fruit to make juice from Tamiami, Nesbitt, 8-52, Seminole, Isabella and Everglades. Grapes need to be fully ripe, crushed, and then squeezed to extract the juice. Grapes were first washed and picked off the stem into a bowl. For crushing we tried the potato masher, but the best tool was the electric ice crusher. (see above) We also tried the Green Star Juicer which could not handle the amount of pulp. Then the crushed grapes were squeezed using two different techniques. The crush grapes were squeezed in a “grape press” but we also used a clean paint strainer bag squeezing and twisting it until all available juice was extracted.
We toyed with the idea of crushing them with clean feet in some kind of a vat, but decided we would hold off on that technique in the first year. Juice seems to hold well in the fridge, and we discovered that pouring the freshly pressed juice into ice cube trays, freezing, and then putting into zip lock bags, would keep the juice for later in the year. However, frozen juice does not taste exactly the same as freshly pressed.
Raisins: We made raisins in our home dehydrator from four different varieties, but discovered that the smaller grapes like the Tamiami and the B-52 made a better raisin than the larger varieties.
We tried various temperatures from 90-125 degrees on the dehydrator and found that the 125 degree worked very well. Raisins were spread out in a single layer with multiple trays and would be dry in a single day if started in the morning. It’s best to continue tasting the raisin along the way to make sure it is not “overdone.”
These are all seeded varieties and we discovered that the seed inside would also shrink and become lightly crispy making it easy to eat. Our Tamiami raisins are now safely kept in a sealed Ball Jar in our pantry for later use.
Jelly: I like to make jams and jellies without using sugar.
I experimented with making a refrigerator jelly. I took the squeezed leftovers from making juice, that included skins and pulp and gently pulsed them in the Vitamix, then simmered them gently in a pot with a lid for a few hours. I then strained out the juice, returned to the stove and added some pectin
that is specifically for use with low or no sugar, simmered that until thick, let it cool and then added a bit of honey tasting it before putting in a jar to be kept in the fridge. I could have added a squeeze of lemon juice that sometimes improves taste.
Frozen Grapes: With most varieties, all you need to do is wash the clusters, remove the berries from the stems, make sure the skins are dry, and then pack the fruit in air-tight freezer containers and seal them. Thawed, or partly thawed grapes can be used on cereal, in cooking, or in a bowl by themselves. You can also try blending them in the Vitamix or blender with yogurt or bananas to make smoothies.
Dolmas: I also made Dolmas (stuffed grape leaves) and everything was delicious but I had picked the wrong grape variety for the outside leaf. Next year I'll make sure that the variety I use has no white felting on the back. Even tho you can't see this on the back of the young leaves, it still produced a tougher leaf, even when cooked. Chewy is not the mouth feel you want with the Dolmas! I'll try again in the Spring.
Lastly, a word about Grape Seeds and New Grape Research: In our markets today, there are only a few varieties of grapes available for purchase, and they are all seedless varieties. They have a mild taste and varieties that are not labeled “organic” are highly sprayed with chemicals. Many but not all seedless varieties are vinifera grapes grown mostly in Europe or California and are for wine making. We have been experimenting with subtropical varieties that all have seeds. So let’s look at the seed itself from a nutritional perspective.
Research shows, grape seeds are full of important nutrients and have many health benefits. Grape seeds are edible and safe for eating everyday. Grape seeds are rich in vitamin E, linoleic acid, and powerful antioxidants. So let the little crunch be a nutritional addition to your daily food.
Over the past 10 years, there have been many grape studies looking at the health affects of eating grapes. Here are just two.
From Critical Reviews in Food Science and Nutrition Volume 53 Issue 11
And from the Journal "Foods": DOI: 10.3390/foods11131984
We would once again like to Mahalo Western SARE for their amazing support for this Research and Education Project (please meet Stacie Clary from SARE) who recently visited our Project with our PI Ken Love from the Hawaii Tropical fruit Growers Association, and of course Claw Claw our kitty in the background. Photo Below.
Also, if you had some good photos from your Summer Harvest please make a post with #grapesforhawaii so that we can all see grapes growing across the State. Mahalo!
Until next time, a hui hou,
Gerry Herbert and Nancy Redfeather
Kawanui Farm, Kona, Hawai'i