BREWING
Hops and hop products
one can sanely argue that adding some- thing wet to something wetter should be described as dry hopping. Methods There is an old phrase, if you ask ten brewers the same question about brewing, you’ll get ten differ- ent answers. This diversity of opinion seems to be reected in methods for dry hopping. There is a multitude of different approaches in use, some born of design and some of necessity. The technology of dry hopping is evolving from breweries cobbling together a system which does a reasonable job into the new automated systems, which have been designed to bring precision to the process. All t into two categories, static and dynamic extraction. In static methods the hops are sub- merged in the beer and left to steep. In dynamic methods, hops are added into a recirculating ow of beer or into a vessel where the beer is caused to move by agitation. With static methods the extraction is less efcient in terms of time and materials. With dynamic meth- ods, extraction is increasingly rapid and efcient with increasing movement. As well as a more complete extrac- tion of the good stuff, dynamic methods also extract more of the unwanted stuff (bitterness, polyphenols increased pH).
Prix . The chaos in the tank helps to break up the pellets and suspend the hop material. If the hatch on the top of the vessel is not secured immediately after addition, a Vesuvius of foam will ll the cellar. I’ve worked in several brewer- ies where hop murals had been left on the ceiling by such events. If the vessel is cylindroconical, any hops sedimented in the cone or oating on the top can be (re)suspended semi-effectively in the wort/beer by bub- bling CO 2 up through the bottom outlet. The CO 2 leaving the beer during addition and rousing will take with it volatiles from fermentation and dry hopping. One regional brewer in the UK used to dry hop by lling bags designed to launder lingerie with milled pellets which they tied to the top of the FV. They used to order bulk lots of the lingerie bags online. One can only wonder what theories the suppliers of the bags came up with to explain why a brewery had so much lingerie and needed to wash it so frequently. The equivalent method, using whole hops, is lling porous sacks with hops and enough weights to sink it and launching the lot into the FV. The buoyancy of whole hops is such that you almost need to add the equivalent volume of solid stainless to stop the hops bobbing around on the surface of the beer without getting wet. With the heights, loads, conned spaces and asphyxiant gas involved, dealing with the sacks before and after this method is hazardous on many levels. Extraction of aroma is also slow and modest. All the above methods will cause a big increase in beer DO 2 – so are only sensibly applicable to beer with active yeast in suspension. Tank transfer addition An alternative method is to add the hop pellets or whole hops in bags to a tank, purge the tank with CO 2 to minimise DO 2 pick up and transfer beer into the tank. This method has the advantage of the turbulence created when lling allowing the hop pellets to mix into the beer. The sacks of whole hops can be fastened to the bottom or sides of the tank to ensure they are submerged, or you ll the tank so there is no head space and the hops are forced into the beer. These whole hop methods were used for years at Belgium’s Brasserie d’Orval and Sierra Nevada Brewery. One fairly obvious downside is that it’s an extra tank to clean.
All forms of hops can be used for dry hopping. Whole hops were obviously the rst to be used, added to casks when racking. The type 100 pellet was developed to make this job less
messy. Whole hops have the greatest poten- tial for carrying a large dose of DO 2 with them and provide a comparatively low yield due to
the lower contact area between hop material and beer. Pellet hops provide
a greater surface area and hence greater extraction of
Braukon HopGun Pro
avour compounds. They are easy to dose and homogenise for slurry dosing but do still carry with them the potential for DO 2 pick up. The main issue with pellets is their capacity to swell when wetted, sometimes to 1000% of their original volume. With increased swelling comes the potential for increased beer losses. Enriched (more lupulin gland – less bract) pellets (T60, T45 and T33) have lower proportions of bract particles and hence potential for swelling. Hop powders have similar dry hop- ping properties to pellets but are harder to dose and tend to oat on the surface of the tank especially with enriched powders. Again, with greater enrichment comes less swelling and smaller losses. I should mention that emulsied hop oils provide
1. Static methods Direct addition
The simplest static method for dry hopping is to climb up to the top of an FV and tip the contents of a bag of pellets (or sometimes a slurry of pellets in water) into the tank. It is made slightly dynamic if the beer has a high level of CO 2 and is relatively warm. As the pellets break up, they provide nucleation for CO 2 bubble formation and the tank zzes up like a bottle of Champagne after a Grand
the greatest yield and lowest losses. They do not like being in beer, so a static mixer is required
after dosing. I won’t discuss them any further because no
Also from Braukon, this time in collaboration with a leading hop supplier is the Braukon Hopsteiner. It was launched last year so is the newest technology and also judging by the picture the one most likely to have been designed after reading some Jules Verne
42 ● BREWER AND DISTILLER INTERNATIONAL I october 2019
i bd.org.uk
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