13,703
edits
Changes
added section "Misuse of Traditional Meaning"
The barrel can be refilled with either fermented beer or wort. Choosing to refill with wort could eventually lead to a lot of trub build up, however, there might not be any negative flavor effects from doing so. Wort will ferment in the barrel and might cause a blow off unless there is adequate headspace (in which case the brewer should top up the barrel after the wort ferments). Choosing to refill with beer that is first fermented with brewers yeast or with a mixed culture might be more practical for avoiding blow off issues and for group barrel projects for homebrewers because individual brewers can brew the refill beer at any time, and then meet to refill the barrel. See [[Solera#Yeast_Autolysis|Yeast Autolysis]] below.
==Misuse of Traditional Meaning==
The term "solera" has deep roots in the history of Sherry production dating back as far as the late 1800's. As such, the term has a fairly strict and traditional meaning in the Sherry and wine industry. See [https://www.sherrynotes.com/2013/background/sherry-solera-system/ this article by Ruben Luyten] for an in-depth definition of the solera system as it is known in the Sherry industry. As a part of the traditional solera system, multiple tiers of casks are used in the system. There appears to be no known use of the term "solera" in the wine industry to apply to a single tier blending system (this is referred to as "perpetual blending" in the wine industry). As such, some brewers argue that unless a solera consists of multiple tiers, such as the system at [https://www.youtube.com/watch?v=bjMB0E_KeYI Cambridge Brewing Co. for Cerise Cassée], which is the oldest known beer solera since 2004, that it is not a true solera. The alternative term "perpetual blending", which has been applied in wine world to refer to single vessel blending systems <ref>[http://www.champagneguide.net/information/glossary Peter Liem. Champagne Guide. "Glossary of Terms". 2009. Retrieved 03/06/2018.]</ref>, has been offered as an alternative and more accurate word to use for single-vessel blending systems.
There are arguments defending the use of the term "solera" in the brewing industry and in homebrewing to refer to single-vessel blending systems. These include:
* Terms are borrowed and changed all the time, and that the nature of language is to evolve.
* The term has been used since at least 2006 by homebrewers to describe a single-vessel blending system <ref>[https://aabg.org/new-member-info/bourbon-barrel-barley-wine Ann Arbor Brewers Guild. Walloon Solera Ale in Sweden. 2006. Retrieved 03/06/2018.]</ref>.
* Reversing the precedence of calling single-vessel blending systems something other than "solera" will be impractical now.
* The brewing of the fresh beer in a steel fermenter could be viewed as the "first stage of a solera", so as long as fresh wort is not added, it is still a solera (this argument is countered by the term "secondary" being used in brewing to rack liquid from one fermenting vessel to another).
* The term "perpetual blending" is less marketable than the term "solera".
A full debate of these points and counterpoints can be found on [https://www.facebook.com/groups/MilkTheFunk/permalink/2012252492136288/ this MTF thread], with comments by Will Meyers of Cambridge Brewing Company.
See also:
<youtube height="200" width="300">bjMB0E_KeYI</youtube>
<youtube height="200" width="300">lfyGPHs7dOY</youtube>
==Yeast Autolysis==
Yeast autolysis is the rupturing of dead yeast cells and produces meaty or rubbery off flavors <ref>[http://byo.com/kegging/item/182-beat-yeast-bite Freccia, Nico. Beat Yeast Bite. Brew Your Own Magazine. April 1997. Retrieved 2/20/2015.]</ref>. When it comes to sour beers, Lambic producers often let their beers age in barrels on the trub for up to four years without effects of off flavors from yeast autolysis. The hypothesis is that the ''[[Brettanomyces]]'' will metabolize the off-flavor compounds produced by the bursting ''[[Saccharomyces]]'' cells, and use them as nutrients <ref>[http://www.themadfermentationist.com/2013/05/second-pull-wine-barrel-solera.html Tonsmeire, Michael. Second Pull Wine Barrel Solera. The Mad Fermentationist Blog. Retrieved 2/20/2015.]</ref>. Therefore, many people have reported that they have successfully avoided yeast autolysis in solera projects, as well as just allowing sour beer to remain in the primary fermenter for the entirety of its aging. However, as the solera ages, trub buildup can potentially become be a problem for logistic reasons (such as clogging ports). Will Meyers of Cambridge Brewing Company reported an eventual autolysis issue with his solera <ref>[http://www.themadfermentationist.com/2013/05/second-pull-wine-barrel-solera.html Tonsmeire, Michael. Second Pull Wine Barrel Solera. The Mad Fermentationist Blog. Comments section, July 30, 2014 at 9:39 PM. Retrieved 2/20/2015.]</ref>. Lauren Limbach of New Belgian Brewing reported tasting "goaty", "dog food", "caprilic and capryc" flavors in barrels that had not been cleaned out after a few years, and upon rinsing the barrels out with de-aerated water the resulting beers were "bright and beautiful" (the barrels were filled with clean beer and not inoculated; assumably the microbes surviving in the wood were enough to produce good results) <ref>[https://soundcloud.com/craftbeerbrew/podcast-episode-21-new-belgiums-wood-cellar-director-blender-lauren-limbach Lauren Limbach. Craft Beer and Brewing Magazine Podcast. Episode 21. 02/16/2018.]</ref> (~37 minutes in).
Whether or not the brewer elects to refill the solera with wort or fresh beer can also potentially play a role in yeast autolysis issues eventually creeping up in a solera. If flavor issues from yeast autolysis are going to occur, adding wort will create a thicker trub, which could lead to autolysis issues faster. In either case, theoretically, these issues can be avoided. One method for avoiding off flavors from yeast autolysis is to rack some of the trub out of the solera when the seasonal pulls are taken. Another method is to rack the solera to another vessel once a year or every other year. Once removed from the trub, the ''Brettanomyces'' should be able to clean up the off flavors over time. See also [[Mixed_Fermentation#Reusing_a_Sour_Yeast_Cake|Reusing a sour yeast cake]].
See also:
* [https://www.facebook.com/groups/MilkTheFunk/permalink/1966542510040620/ Will Meyers of Cambridge Brewing Co. shares his experience with autolysis and running the oldest commercial solera program for sour beer in the US.]
==Articles on Solera==
In addition, see the [[Blogs]] Wiki page for blogs that may contain more articles on solera.
==See Also==