OnTap Magazine

Hops contain a multitude of flavour compounds, with some estimates putting these at around 500 different flavour-producing elements. No wonder beer is such a complex beverage. These flavour compounds can be collected into three broad categories: hydrocarbons, oxygenated hydrocarbons and sulphur- containing compounds. Of these categories, hydrocarbons (also known as 'terpines') represent the lion's share of hop flavour that brewers crave. Unfortunately, these are also the most volatile of the three, which means that any form of heating will degrade them, hence the increasing popularity of late and dry hopping techniques. Flavours associated with these oils tend to be grassy, herbaceous and dank. Other compounds are very resistant to heat, and so tend to remain in the beer no matter what. These flavours, which can range from citrusy to floral, are likely to be present in beers where first-wort hopping has been applied. Now that we knowa bit about howhops operate, let's turn to the practicalities of improving your use of hops. HOP CHEMISTRY 101 TIPS FOR FIRST-WORT HOPPING TIPS FOR USING LATE HOPS IN THE KETTLE Flying utterly in the face of received brewingwisdom, the technique of first-wort hopping is the (somewhat) controversial practice of allocating some of your hop bill to add to the post-mash, pre-boil wort. This type of hopping regime is meant to inject a more elegant, softer, and better- integrated hop flavour to your beer than can be attained through just kettle or fermenter additions. Bitterness levels may increase somewhat, but because the actual time the hops spend boiling stays the same, you shouldn’t have to adjust your recipe too much. To convert an existing recipe into one that includes first-wort hopping, you will need to add a proportion (anywhere from 25-50%) of the hops you would have used early in the boil (i.e. bittering hops) to the wort as it runs off from the mash. Depending on the brewing approach you use, you will have to add your first-wort hops as follows: • All-grain (e.g. using a converted cooler as a mash tun): Add the hops to your collection vessel as you extract the first wort from the grain bed. • Extract with specialty grains: Heat your water to steeping temperatures (60- 75°C), dissolve your malt extract, then add the hops to the wort before you start steeping your specialty grains. • BIAB: Add your hops to the kettle as soon as you've lifted the bag and it has started to drain. Whichever approach you adopt, it is important to have the first-wort hops heat slowly in the wort (around 30-45 minutes) as it comes to the boil. So, if you usually collect wort more rapidly, you'll have to slow down, or if you're an extract brewer, bring the wort to boil more gently. It is this prolonged contact time with hot, but not boiling water that seems to account for a more rounded, softer hop flavour. Then, once you have the wort boiling, add the remaining bittering hops as usual, following the standard recipe. Generally, studies of first-wort hopping show better results when brewing lagers, pilsners, and light ales (e.g. Kölsch, blonde ales). Using the technique for hop-forward styles like IPAs might not make that much sense: you are, after all, chasing a more pronounced, brighter hop character in such brews. For an enhanced hop flavour and aroma without too much bitterness, you should consider late hopping – that is, adding hops post-boil, but before the wort cools down to pitching temperature. Now just because the boil is over, that doesn’t mean you won’t extract any bitterness from late hopping. Adding hops immediately after flame-out, or while forming the whirlpool, will still extract a fair amount of bitterness, so account for that in your recipe formulation. For maximum flavour and minimum bitterness, however, wait for the wort temperature to dip below 80°C before adding your late hops. In a typical 19-litre batch, you can easily add 30-60g of hops as a late hop addition for solid results. Alternatively, convert an existing recipe by pushing all of your late addition hops post-boil. You can even experiment by brewing a beer without any bittering additions at all and only using late hopping. Several contemporary approaches to sessionable IPAs use this method (for instance, Soul Barrel's Tropical Parade, featured in the summer 2021 edition of On Tap). 1 2 4 5 3 ontapmag.co.za | Autumn 2022 | 51