After a few years working with vineyards in the UK we have drawn out some of the most valuable data you can collect in your vineyard. Tracking these 10 metrics will help you better understand how to manage your vines and optimise your grape quality and yield – directly benefiting your bottom line.
Producing great wine is both a science and an art, we help take care of the science so you can focus on the art.
Some of these metrics are measured at the level of individual vines, whilst others are measured on a block by block basis. Most vineyards don’t monitor every vine, but take a representative sample from each block of vines. Head to our website for advice on how to choose which vines to sample and more.
The vineyards we work with use our app, Sectormentor For Vines, to record all of the metrics featured here and then use the graphs on our site to build up a picture of how to best manage their vineyard.
Special thanks to Will Davenport for his very helpful advice on these metrics.
(Bride Valley Vineyard on a frosty morning)
1. Date of bud burst / flowering / picking
Everything in farming is weather dependent, however, by recording the date of bud burst, flowering and harvest, after a year or two you are better equipped to predict your harvest date which is very helpful when planning tank space amongst other things. If the flowering date is early then you are likely to have an early harvest, and you can get everything in place. Read more here
2. Date of frosts and severity
Frost is one thing that can seriously affect bud burst, flowering and harvest patterns, so it’s good to record the date and severity of any frosts. At the very least it provides context when looking back on data as it will affect everything. Read more here
(Grapes ready for harvest at Davenport Vineyards)
3. Counting flowers per vine
Recording the flowers per vine in late Spring/early Summer allows you to do an early prediction of your total yield. It’s only an approximation as a heavy hale storm during flowering, or rain all Summer long can really affect the yield. However it’s good to do these estimates so you can start planning at least for maximum predicted yield quite a few months before harvest. You need to have numbers for average bunch weight and percentage fruit set to calculate the yield.
Our Sectormentor For Vines app makes it very easy to count flowers per vine as you put an RFID tag at a each of your sample sites. When doing a flower count, scan the tag and then enter the number of flowers you count on each vine for the next 10-20 vines (depends on your sampling system). Sync when back in the office and you will see the average flower count per block straight away. Read more here
4. Counting bunches per vine
About a month before harvest many vintners count bunches per vine, this more or less lets you know how much you will yield if you know number of vines and can approximate a bunch weight based on historical bunch weight averages. Many people also measure bunch weight over the years to get an approximate bunch weight (see below). Read more here
5. Bunch weight (kg/vine)
Bunch weight at harvest is a key part of any yield prediction program. One important goal of recording bunch weight at harvest is not to predict the yield that year, but to provide an average bunch weight to help with yield prediction in subsequent years. Careful collection and maintenance of bunch weight records from year to year is pivotal to improve yield estimation. Proper record keeping will also give the you a better sense of the annual variation related to adverse climatic conditions. Read more here
6. Measuring grape sugar
Almost all winemakers use a refractometer to help them determine when to harvest. There is a direct correlation between the amount of sugar present and the ability to make wine. You can either use a refractometer that gives you an Oeschle reading or a Brix reading. Both scales indicate the sugar levels in the grape.
A graph of grape sugar over time is hugely useful as ripening is not linear. Of course weather affects ripening, but you can still see trends like that some varieties ripen faster and then there is only limited benefit from leaving them on the vines for longer. Read more here, including information about Sugar:Acid ratio
7. Measuring titratable acid (TA)
Acid has an arguable optimum level of 6-9 g/L for reds/whites and 11-13 g/L for sparkling. It’s time to harvest when the acid comes closest to these optimums at the same time that sugar comes closest to optimum level of around 22 Brix. In many cases optimums are not be reached, so there are other rules of thumb for judging readiness of harvest (use Brix:TA Ratio). As Will Davenport told us “Many UK vineyards pick sparkling wine grapes at higher levels than this in years when grapes struggle to ripen.” Read more here
(Harvest time at Davenport Vineyards)
8. Pruning weight per vine / Cane no. at pruning
Mid-winter is an important time for pruning vines in the UK. If you record the weight of material pruned off each vine and the cane number at pruning time, then you can work out the weight of each cane and understand the vigour of each vine.
Assessing the vigour allows you to determine how many buds per vine you want to prune to. For example if you have high vigour (or heavy canes) then prune for lots of buds to try and manage leaf growth to be less. Some vineyards choose to record no. buds per vine as a clear record (and good check) of what actions were taken in the vineyard.
The pruning weight measurement is also used as a guide to whether the vineyard needs more nitrogen applied (compost/manure in organic systems) and is often a better indicator than soil analysis. Read more here
9. Kgs picked
Everyone wants to know their yield. Whether everything you do is to optimise yield, or not, it’s still important to know the total kgs picked as that can inform pruning techniques, and how you care for the vines going forward. If you can keep collection trays from different blocks separate when harvesting, and count them separately, then you can better understand how an individual block is doing and adopt management techniques accordingly. Read more here
10. Actual number of vines per acre: record dead/missing vines
At the end of each season it’s important to record the number of dead or missing vines in each block. This allows you to calculate the actual number of vines per acre in a block, rather than the number that were originally planted – just 5% missing vines can skew all other predictions. This number is key for yield predictions. Read more here
Will Davenport sums it up nicely,
“A vineyard manager / owner can never have too much data, both current year data and historical data, to assist in making decisions and predicting the next 6 months. The normal problem is that collecting and maintaining data can be very time consuming, and that is where Sectormentor helps – it makes it much faster, tidies everything up and allows me to look up things that the vineyard manager has measured.”
If you would like to find out more about using Sectormentor for Vines for your vineyard then please get in touch here