by Mike Retzlaff
For at least the last 20 years, I’ve been adding spices to beer wort with about 10 minutes left in the boil. I’ve done this because I probably read it in a book and never really thought about it. This technique was reinforced by being a common practice by everyone else. I recently read something which wasn’t shocking or an “aha” moment but did give me pause to think. Someone remarked that a friend of his, a professional chef (and non-brewer), commented on this practice by asking “would you throw a tea bag in a pot of water and boil it for ten minutes? Would you pour coffee grounds into a pot and boil them for the same amount of time?” Of course, nobody would (well, most wouldn’t). The volatiles you want from the tea or coffee will burn off with the steam and any bitter components are more likely to be extracted.
We all add hops to the kettle at various times to get the effects of hops on the beer. The timing of the additions is dictated by what we’re trying to achieve. We can use First Wort Hopping and/or a bittering addition usually with 60 minutes left in the boil. This gives the alpha acids in the hops a chance to isomerize which makes them useful. Another addition might be at the 10 – 20 minute mark for flavor and then a late addition at the 0 – 5 minute mark for aroma. Some brewers add these late additions to the whirlpool or hop back. Dry hopping is another time to add hops to enhance aroma.
Given this concept, an obvious answer would be to add the spices at flame out which provides the most from those additions without driving off the delicate flavors and aromatics. Most spices consist of the seeds, roots, or bark of various plants and can contribute tannins if boiled. To temper this concept with reason, the spice additions aren’t usually massive and the amount of tannins that could be rendered would be rather insignificant anyway. This entire consideration is what my old English friend would call “skinning fleas for hides and tallow.”
Comparing tea and coffee to spice additions simply does not apply.
Tea and coffee are steeped and then consumed hot, immediately after preparation. Beer, after the boil, is maintained in an environment conducive to microorganisms taking over. Beer must be kept sterile during this extended time. The brewer must do everything possible to minimize contamination. Many years ago, brewers figured out that a 10 minute boil almost always kills off any spoilage micro-organisms. However, can hot steeping be any riskier than dry hopping?
If we decide to embrace the risk of possible contamination, do we need to adjust the amount of spice added to the kettle when reducing the contact to steeping only? The answer to that is yes and no; it depends on the spice. Some spices like cinnamon and black pepper don’t give up their flavor and aroma easily and can require a minimum of 3 to 5 minutes in the boil. Other spices like anise, coriander, cumin, or chamomile flowers, should work fine with a 5 – 10 min. steep without any adjustment to the amount used. Another factor is the actual amount of oils in the spices. Like hops, it varies from year to year and from grower to grower. Even when buying spices in bulk, you don’t always have a certificate of analysis. Even if you did know the exact amount of spice oils in your inventory, I doubt that Glenn Tinseth has an online calculator in his back pocket.
Because there are major differences between the needs of commercial and home-brewers, there doesn’t really seem to be a good, comprehensive answer to this but it’s worth pondering and experimenting with future brews. In the meanwhile, the old routine of adding spices during the last 10 minutes of the boil is enough to kill even E. coli bacteria without being overly abusive to all but the most delicate spices.