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Harvest Diaries

Getting peripherally involved in making the wines this year. Just a little bit more than last year.

Dan Kirby

Oct 8, 2023

Hey Team,

I’m trying my best to get involved in the winemaking at the vineyard this year. It’s a bit tricky given the fact that I’m not really sure what the heck I’m doing in real life. I’m not the most practical person, but I understand pretty clearly the bookish version.

You can follow along with the updates on my instagram account.

Ben & Oli are the ones doing all the actual, hard work. Putting in the long hours most days, making all the important decisions, and putting all the planning into action.

So, what am I doing?1 I still have another job, so I physically can’t go ‘all in’. I’m roughly doing 3 or 4 days per week, chipping in when I’m needed. As much as I’d like to be there everyday, I get the sense that there isn’t quite enough to do that would require me to be there all the time.

Picking

I haven’t been our picking yet! It seems to me that the English vineyards have an over reliance on volunteers paid in tea and biscuits. We have a Membership Club where only members of the club get to experience, and help for the harvest and get a bit closer to the winemaking behind the scenes.

The majority of our pickers are paid. Most are current staff from the vineyard and cellar door. We’ve taken on some additional pickers too, generally wine interested people and relatively local. So a total pool of pickers around 15-20 I think.

I was down for picking one day, but it rained heavily the night before so we pushed it back. I’ll probably get involved at some point in October.

So far the sugars are a little lower than the 2022 harvest, so we’re trying to pick slightly later anyway, balanced with keeping the grapes healthy. Add that to the very high yields this year, and we wouldn’t be able to get all the fruit off quick enough if we hadn’t started already.

Grape Processing

As the grapes come in, the thing I’ve been helping with the most is processing those grapes. It’s a fairly manual process, there’s the big grape bins that hold about 400 kg of fruit. They get tipped onto the sorting table, we don’t do a lot of sorting, we try and get that done in the vineyard.

Depending on the variety, the time we’ve got, and the wine it’s going to make, we’ll decide whether to press them as whole bunches, or crush/destem them first2.

The plan is usually decided by the 3hr press cycles, and the amount of fruit we’ve got that day. The press is an inert (nitrogen) membrane press, that we can use completely inert or conventionally. With whole bunch taking around 1.5 tonnes, or if we crush and destem we can just about squeeze in 3 tonnes, give or take.

My job here is mostly lugging boxes of grapes around, getting them into the press or the crush/destemmer, then helping to clean everything. The old saying that 50% of making wine is cleaning stuff is certainly true.

The Laboratory

Knowing these three figures is helpful: Oe, pH, and TA.

Initially we do simple testing with a hydrometer to get you the Oe or sugar, so we can calculate the potential alcohol, and know where the levels are pre-ferment and as the fermentation progresses.

We also test juice on arrival for pH, a fairly straightforward process with a snazzy pH probe. Then the marginally more complex titration of checking for TA (Titratable acidity, not Total or Tartaric). Which is through adding sodium hydroxide to some diluted juice, raising the pH to 8.2 and then calculating the amount of acid you added3.

We also have a spectrophotometer4, which uses UV light at various wavelengths to do its magic. We use it for various things throughout the year, such as SO2 and I think for MLF checking.

The main thing at harvest we’re using this for is YAN, specifically Primary Amino Nitrogen (NOPA) testing.

For the geeks.

The amino nitrogen groups of free amino acids in the sample react with N-acetyl-L-cysteine (NAC) and o-phthaldialdehyde (OPA) to form isoindole derivatives.
Amino nitrogen + N-acetyl-L-cysteine + o-phthaldialdehyde

This reaction can be quantified and measured using UV light at specific wavelengths.

Broadly, this is yeast assimilable/available nitrogen, which gives us an idea of how much nitrogen derived from amino acids are in the juice prior to fermentation. This figure will give us an idea of how quickly or slowly the ferment might run, and gives us the chance to do something about it, if needed.

Big fan of being in the lab, and I think over the coming weeks I’ll be in the lab a bit more, as I can just crack on with the testing.

Ferment Checks

Once the juice is starting to ferment we keep a pretty close eye on them. The first grapes came in around two weeks ago, and we only have a few tanks beginning to ferment.

We cool and settle the white and rose wines for a few days, and then we rack them before ferment begins. This gives us clearer juice and retains some freshness.

Once we’ve selected and pitched the yeast, we keep an eye on the juice every day to see what’s going on.

Once the wines start to ferment, you can hear it, see it and taste it. There’s some fizzing, and some prickle in the juice. We’ll check the Oe and the temperature of the juice in every tank and barrel, so that we can see and plot the start and end of fermentation on a spreadsheet.

The actual testing tastes a minute at most. The time consuming part of this job is getting the juice samples, particularly if you’ve got the same wine is across a few barrels. Then also, getting the juice you’ve tested back in the tank or barrel. Plus the tidying up and cleaning, obviously.

Over the next few weeks it’s likely we’ll have 10 tanks fermenting, and probably more barrels and bins for red wine going, all of which will need daily testing. So, at least I’ll have something to keep me busy.

Now that I’m getting back into study mode, all of this is remarkable hands-on experience for really understanding things in context.

Nothing you can read in a book can really solidify concepts as quickly as doing it for real.

My Actual Job

All the while, I’m doing my actual job. The week that the first grapes came in I was still hosting vineyard tours, pouring our wines with a couple of trade customers, and putting together a pre-order on one of the wines we made last year that is being bottled in October.

So, there’s always something to do, but I’ll always try my best to clear the diary for harvest.

Dan