Thursday, April 19, 2007

Kiwifruit Lesson.

How's that kiwifruit crop looking? Good actually....but how far away from picking is it? Well a few weeks at least. One of the jobs I do at this time of the year is keep tabs on how the crop is maturing. It is all looking good but what is going on inside the fruit? The sugar levels are building and so is the dry matter....that means it is starting to mature or ripen. How can I tell this? Well firstly it is the time of year for it to ripen; but also cause I'm Brix Testing some sample fruit using a refractometer.
This is how I do it.
-Go and select some fruit from different blocks of the orchard.( 10 this time )
-Bring them back to the kitchen bench and cut a thin slightly curved slice off each end.
-Squeeze a drip of juice from each of the fruit slices ( 2 drips total per fruit ) onto the prism of the refractometer. (2nd photo )
-Close the upper plate down to spread the juice right across the prism. Hold the prism up to my eye and toward a light source. It's not easy to see but there is a scale printed on the lens which tells the level of soluble solids ( sugars ) in the sample.( the same method is used for grapes in the wine industry )
- read the result for that fruit and record it.
- wipe the prism clean after each fruit sample.
- Add up the 10 readings and divide by 10 to get the average. ( and that the current brix level for our fruit ) ( Ours is progressing towards being ready but is probably about 2 weeks away. Cold nights ( chilling ) will make the levels rise fast. Rain will slow it down and dilute it. Frost will cause a scare cause the crop can get we want colder nights but not too cold!
( What I have described is simplified a bit as there are lots of rules about where to pick the sample from; time of day; number of fruit in the sample, but you get the general idea )
At one time many years ago ( 30) the 1st May was when kiwifruit picking started on some orchards but as more was learnt about maturity and taste the industry has used better methods to decide when fruit should be picked. When our crop is ready it will get " officially" tested for Brix levels and for dry matter ( different test using microwave drying ). Then after that we will wait our turn to pick. The packhouse has to allow only as much fruit as they can handle to be picked at any time so it is all organised by the packhouse facility...... often that means a lot of waiting. The waiting is hard as frost or wind could strike and ruin a good crop, so things sometimes get a bit tense. This is our 25 export crop! ( we have lived here 29 years now )
We have been eating some lovely fruit which I picked 2-3 weeks ago that were mower damaged or extra big or flat shape ( I just couldn't throw them on the ground to be mown up ....glad I kept them cause they are ripening up nice and sweet. )
Right now we get to catch up on other jobs like garden and firewood and nut collection and Autumn things...soon there will be leaves everywhere...the colours are great on Viburnums Dogwoods and Hydrangeas; the Oaks are just starting. Lovely still, calm, days. Mellow..... Long may it last. No storms please!


Sheila said...

Gosh..who sounds so complex. Like all farmers you are at the mercy of the weather.
Next time I buy a basket of kiwi fruit I'll think of you..!!

Shirley Goodwin said...

So THAT"S how you know they're ripe!

Sooziii said...

I love it when you give us all the inside dirt on how to grow your lovely fruit. We go to the store and pick out what looks OK and take it home and eat and never think about what the grower has done and gone through to get into our mouth.
As well as being a farmer it sounds like you are a scientist as well - add that to your many other talents - now that a real woman!

meggie said...

Thanks for all the info Ali, it was very interesting. Though I grew up in the heart of Kiwi fruit, I left the town before it became the 'Capital', & before the crops became prevalent.
We didnt have any growing, but an Aunt did, & we loved the fruit when they were still "Chinese Gooseberries".

Deb H said...

I looks a lot like the instrument we use to read specific gravities on urine samples in rhe hospital.
Interesting stuff.
Your post also congers up cozy images of autumn (my favorite time of year), & here we're slowly moving into spring. It just doesn't seem possible, such a miracle, this internet that allows us to communicate at opposite ends of the earth!