Bits and Blobs and UFOs A HAZY PROBLEM IN NEED OF A CLEARER SOLUTION W R ITTEN A ND PHOTOS PROVI DED BY G A RY SPEDDI NG, PH.D.
Over time many alcoholic beverages are likely to form a haze, show a light precipitate, or even exhibit a potential for significant turbidity which can be caused by colloidally dissolved organic substances or inorganic metal or mineral deposition. Significantly, sediments and hazes are on the rise in craftdistilled spirits. Such issues cause alarm for distillers unaware as to their origins or how to prevent or alleviate their formation. We will thus discuss the origins of these unsightly issues and discuss colloidal stability of beverages. To do this we need to dip into the Scotch whisky literature and reach back to the 1960’s for some cogent discussions, and even much earlier. Even then we will see that there are still unknowns out there with room for speculations about Unidentified Floating Objects (UFOs) in different kinds of distilled spirits. Let’s try to clear the muddy waters or the “greying” spirits — read on. 92
ver the past two decades we have been presented with an ever-increasing number of spirit samples with hauntingly eerie-looking sediments, precipitates, gels, and globs of unidentified (and sometimes unidentifiable) matter. The situation is getting worse as more craft products enter into the marketplace and, furthermore, the extent of matter appearing in solution is increasing to the point that sometimes the entire bottle appears like a snow-globe ornament, much like the beer colloidal mess shown in the figure below. A lesser cluttered example of a floc in a bottle of a white spirit is also shown. The urgent calls received are requests for us to indicate to the distiller (as for the brewer) how to resolve the issue. There are two problems to this, one being the time and expense needed to try and pinpoint the compositional nature of said UFOs (Unidentified floating objects), unless it is one of two key causes (see below). New causes of hazes are being discovered with our application of newer technologies. The second problem is that when we tell the distiller how to possibly resolve it they categorically state that the suggested solution is a nonstarter (again for reasons as will be explained
Beer Colloidal Haze
later); in essence, you can be a puritan or live with these messes! But your customer might not forgive you. The topic of precipitations and hazes (aka. turbidity) in distilled spirits is quite complex and has not been discussed much in the literature since a seminal series of papers published in 1960 and 1963 (Warwicker, 1960; 1963 a, b). Primarily the topic has not received much attention in the public domain (journal publications), probably because most distilleries privately cured this issue with use of completely pure dilution water, free of mineral ions, or via chill proofing and filtration with clearly defined specifications as to mineral content in the filter media, these being key processes for long(er)-term clarity/stability. However, hazes/turbidity include those formed by organic and inorganic types of matter. We recently uncovered some unique components leading to precipitates/suspended solids, possibly based on plasticizers or glass production chemistries (glass-mold release components or oils or coatings, etc., used in plastic tubing/containers). Near infrared microscopy is becoming a useful, though expensive, technique in uncovering the culprits involved in these more unusual cases and may become the tool of choice in advancing our understanding in this area. Though, at
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