Getting ready for the grape harvest – Time to Test

The time is coming close now, when we will be harvesting our grapes and making wine. But how do you know when to harvest?  There are various tests, but on my simplistic level, I will be testing the level of sugars. This gives an indication of probable alcohol level, and depending on the results, plotted over time, you can estimate when to harvest.

Of course that does not take into account weather. Warm weather can speed up the ripening process, so your sugars increase quicker. And of course vice versa if it is cooler.  Then there are the grape predators – birds, wasps and a variety of other insects,… and ducks. We certainly have our share of those and so I have been hard at work putting up scare-cd’s to try and keep the birds at bay. But there is little I can do about the insects. (Even our duck, Maggie, keeps trying to steal the odd grape or three whenever an opportunity presents itself.)

As David (aka Pumpjack) was away in Mexico making wine for a winery there, I was getting my instructions from a long way away, and generally with a 24 hour delay in question and response. But as the tests progressed I started to get a sense of what to do and why.

The first test I did was with a hydrometer, which looks like a long thermometer. You collect about 10 grape bunches, enough anyway to make about 500ml of juice. Bunches are collected from the same grape variety but in various places in the vineyard, to give a better indication of how the whole crop is doing. We have 3 varieties: Chardonnay, Pinot Noir and Pinot Meunier (a classic combination for sparkling). We have so few Chardonnay grapes I was too cautious and did not collect enough to get the requisite quantity of juice to do the test. But with the others I did manage.

Once you collect the grapes, you squish them (this is were feet can come into it, but I used a fingers and a sieve). Then you pour the juice into a tall beaker and float the hydrometer in the juice. The reading is taken from the mark on the hydrometer where it meets the top of the juice.

You then repeat this test every few days, for me it was every 5 days, and record the changes in the readings. They should increase each time and it helps you plot when to anticipate your harvest.

Now because we didn’t have enough Chardonnay grapes to spare to conduct this type of test repetitively, and also it is not the most accurate way to read the sugars, we invested in a refractometer. They cost about 60€, but is money well spent in my book. It allows you to test individual grapes rather than whole bunches. You can either test each grape, making notes as you go along, or what I did was collect about 100 grapes, again of the same variety, but making sure they were from varied locations in the vineyard as well as varied locations on the actual bunches. Again, I squished them, and then I put a couple drops of the juice on the refractometer and it gave me my reading.  Much easier, much faster, a bit more accurate, and I could do it all whilst in the vineyard.

As I did each test and could clearly start to see the fairly consistent rise in the sugars, I started to panic less about David’s delayed return. In fact is has timed out beautifully. He arrived back on Monday and we are anticipating harvest for next Monday ~ assuming the birds, the bees and our duck  don’t get to everything first.  Time to make more scare CD’s.

 

 

Leave a Reply

Your email address will not be published. Required fields are marked *