Storing hops in hot weather so they keep their aroma
Hops are fragile. Heat, light and air turn bright aroma into cheese and hay. Here is how to keep them fresh when the weather is against you.
What goes wrong in storage
Hop resins and oils oxidise. Alpha acids, which give bitterness, drop over time and the aroma oils turn flat or unpleasant. Stale hops can smell of cheese, damp hay or old socks. Heat speeds all of these changes. Light adds to it. A pack left in a hot cupboard for a summer is not the same ingredient you bought.
The rules: cold, dark, no air
Freeze your hops. A domestic freezer, at around minus 18 °C, slows ageing greatly. If you only have a fridge, it is better than a cupboard but will not preserve aroma for long, so use hops within a couple of months. Keep them in their original oxygen-barrier foil pack, or reseal in a vacuum bag or a small jar with an oxygen absorber. Opened bags in a loosely closed container are the worst case.
Pellets, not whole cones
Pellet hops (T90 pellets) store much better than whole cones, because the lupulin is compacted and less exposed to air. If you have a choice, buy pellets in small vacuum-sealed packs. Whole cones are lovely fresh, but they need very cold storage and a tight seal to keep.
Buy small, buy often, buy fresh
Buy only what you will use in a few months. A 100 g pack that you use over three batches is better than 500 g you use over a year. Check the harvest year on the label and choose the latest. When you buy by post, ask the supplier how they ship in hot weather and see our guide on buying ingredients when there is no shop nearby.
For commercial-scale supply chains and the chemistry of ageing, see hop freshness across long supply chains.
Pack for the freezer and the journey
Split a large pack into portions sized for one brew: 30 g, 50 g or whatever your recipes use. Reseal each in a small vacuum bag or zip bag with the air pressed out. Label with the variety, alpha acid percentage and date. Take a portion out only when brewing and return the rest straight to the freezer. Repeated warming and cooling creates condensation inside the pack, which spoils hops.
Hops that travel face the same risk as hops in a hot cupboard. If you carry a pack home from a shop, put it in a cool bag with a frozen gel pack and move it to the freezer the same day. A parcel that sat in a hot depot for a week is worth a sniff test. If the smell is cheesy, ask the supplier about a replacement and tell them where it was delayed. Good suppliers want to know.
Use the hops at their best
Use hops you suspect have aged for bittering, where aroma matters less. Save fresh hops for late additions and dry hopping. Alpha acid readings on the label will be a little high after months of storage, so add 10 to 15 per cent more for bittering when you use old hops. Avoid dry hopping with hops that smell cheesy: sniff before you use.
A pale ale made with fresh hops and a clean fermentation is a lesson in itself. For the kind of local grains that can carry flavour when hops are scarce, see brewing with local adjuncts.
A simple hop log
Keep a small notebook or a spreadsheet beside the freezer: variety, harvest year, alpha acid percentage on the label, date opened and the amount left. When you plan a brew, check the log before you order more. It stops you from buying duplicates and from forgetting a half pack that is now two years old.
When you taste a finished beer, note how the hops came through. Over a few batches you will learn how much age your own palate can tolerate, which no table can tell you.
Power cuts and freezers
If your power cuts out, a closed freezer stays cold for many hours. A full one lasts longer than a half-empty one, so fill the space with bottles of water. If your freezer thaws, do not refreeze hops that have sat warm for a day. Use them soon, in a bittering role.
Common questions
Can I store hops at room temperature?
For a few weeks, in a sealed foil pack, in the coolest part of the house. Longer than that and aroma fades quickly in heat.
Do hops need to be frozen?
Freezing is the best way to keep them. A fridge is better than a cupboard if you have no freezer space.
How can I tell if my hops are stale?
Fresh hops smell fruity, citrusy, resinous or floral. Stale ones smell of cheese, hay or damp cardboard.
Pellets or whole cones for hot climates?
Pellets, in oxygen-barrier packs. They keep better than whole cones.
