If winter is the quiet season for your barrel, summer is the busy one. As the weather warms, everything inside the oak speeds up. That’s good for building character, but it also means small issues, a low level or a tired SO2 reading, show up faster than they do in the cooler months.
A few checks now will keep your barrel in good shape through the hottest part of the year.
What happens inside your barrel in summer
Heat changes how your barrel behaves in four ways.
Evaporation speeds up. Warm, dry air pulls more wine through the staves, so your level drops faster than it did in winter. This is the angel’s share at its busiest, and our guide to why your barrel is losing wine has the numbers by barrel size.
More oxygen gets in. The oak opens up as it warms, so the slow oxygen exchange that builds complexity picks up pace. A little more oxygen is part of how fortified wine ages, but it also means your wine is working harder to stay fresh.
The wine ages faster and concentrates. Warmth speeds up ageing, and as water leaves the barrel the wine becomes slightly more concentrated. It’s one reason barrels from Rutherglen sheds develop the way they do.
SO2 gets used up faster. More on that next, because it’s the one most barrel owners miss.
If you want the other side of this story, our post on what winter does to your oak explains why the same barrel behaves so differently in the cold.
Why SO2 drops faster in summer
SO2 protects your wine by binding with oxygen. In summer there is more oxygen coming in and heat speeds up the chemistry, so your SO2 gets used up more quickly. A level that was fine in July can be too low by January.
The signs are the usual ones: wine that tastes flat, dull or tired, aromas that seem muted, or a faint nail polish edge. If you’ve noticed any of those, our guides on why barrel wine tastes flat and nail polish smells in barrel wine explain what’s going on.
The best time to deal with it is before the heat arrives. If your last SO2 addition was more than 12 months ago, now is the time to check your levels. Barrel Club members can send a sample for free analysis and we’ll tell you exactly how much to add. If you’d rather not guess, send the sample first rather than adding a dose and hoping.
When you have your dose, drop the sulphur tablet through the bung hole. It will fizz, a bit like a Berocca tablet. Pop the bung back in and leave it for around 30 minutes, then give it 24 hours before you taste. Our full guide to SO2 and your home barrel covers it step by step.
How often to top up your barrel in summer
Check your level with a dipstick more often than you do in winter. As a general guide, a 5 litre barrel in a warm shed needs checking every four to six weeks, and larger barrels every couple of months. Top up before you drop below three quarter full.
Because our bulk wine is sold in 2 and 5 litre lots, it’s worth ordering before you need it. Keeping a 2 litre top up on the shelf going into summer means you’re never waiting on delivery while your level sits low.
Choose your topping wine with the age of your barrel in mind. Our guide to choosing the right topping wine walks through every style and tier. And if it’s been a while since you last topped up, don’t panic. Here’s what to do if you haven’t topped up in months.
Where to keep your barrel in summer
Our own barrels sit in Rutherglen sheds that hit 40°C or more in summer, and they do very well. What matters is that they’re full and looked after, not that they’re cool.
What you do want to avoid is direct sun on the barrel, which heats one side far more than the other. Keep it in the shade, away from hot tin walls and roofs, on its stand with some airflow around it but out of strong draughts, which speed up evaporation.
Leaks in hot weather
Hot, dry conditions can shrink staves that aren’t being kept swollen from the inside. The simplest protection is to keep your barrel full. If you notice a weep or a damp patch, our guide on how to fix a leaking wine barrel will help you find the source, and bung putty, swelling and other leak fixes covers the remedies in detail.
Tasting your barrel in summer
Taste in the cool of the morning if you can. A warm barrel and a warm glass make fortified wine taste hotter and more spirity than it really is, which can send you chasing a problem that isn’t there. Draw your sample, chill it for 20 minutes and then taste.
Heading away over summer?
Before you leave for the holidays, top up, check your SO2 and make sure the bung is seated firmly. A barrel that goes into January full and protected will be in much better shape when you return than one left at half full for three weeks.
Your summer barrel care checklist
- Check SO2 before the heat arrives, and send a sample if it’s been more than 12 months
- Top up to the bung hole and keep a spare 2 litre on hand
- Dip your level every four to six weeks for small barrels, every couple of months for larger ones
- Keep the barrel out of direct sun and strong draughts
- Check the bung is seated and look over the staves for weeping
- Taste in the morning, with a sample that’s been chilled
- Top up and check SO2 before any extended time away
Frequently asked questions
Should I move my barrel somewhere cooler in summer?
You don’t need to go to extremes, but getting it out of direct sun is worthwhile. A stable spot in the shade is better than a cool spot that swings in temperature.
Can I draw wine off in summer?
Yes. Just top up afterwards so you don’t leave a large air gap, and check your SO2 if it’s been a while.
Should I add SO2 before summer or during it?
Before is best, so it has time to settle and protect the wine as the heat builds. If you’ve left it until mid summer, add it anyway and give it 24 hours before tasting.
Is it normal for my barrel to lose more wine in summer?
Yes. Evaporation rises with heat, particularly in smaller barrels. Keep up with your top ups and you’ll stay ahead of it.
The takeaway
Summer asks a little more of your barrel owner. Keep it full, keep the SO2 up and keep it out of the sun, and your barrel will come through the heat in great shape.
Questions about your barrel? Our team is available Monday to Friday at wine@stantonandkilleen.com.au or (02) 6032 9457.
