Search: cold break material

The hot break material (trub) and any hop particles which may be present in the wort, must first be removed. After the wort has been cooled to 2 °C, it is filtered through a glass fiber filter. The residue remaining on the filter is dried and then weighed.

Cold break material or cold trub refers to all material that settles out in the process of chilling wort after separation of the hot trub or hot break material. Cold trub can be filtered out of the wort and primarily consists of proteins (48–57 %), tannins (11–26 %) and carbohydrates (20–36 %). The amount of cold break material in wort depends on the quality and composition of the raw materials, brewhouse equipment and wort handling. In academic and professional circles, opinions regarding the significance of cold break material for downstream processes and for the quality of the finished beer are strongly divided [1, 2, 5]. Under certain circumstances, the quantity of cold break material in wort may exceed 250 mg/l, especially where accelerated fermentation is practiced. Ultimately, this can detract from the flavor of the finished beer [3]. Breweries, where removal of the cold break material has been practiced successfully, determine the quantity of cold break in their pitching wort at regular intervals, in order to evaluate the efficacy of their separation equipment.

Instead of brewhouse yield, quite often the cold wort yield is calculated. Cold wort yield is particularly recommended for wort produced using adjuncts. Extract yield is understood as the amount of extract in a batch of wort relative to the amount of extract in the raw materials used to produce the wort.

The solids are separated at approx. 85 °C by means of filtration and are determined through weighing.

DMDC (Velcorin®) is used for the cold sterilization of non-alcoholic beverages. It essentially kills yeasts, bacteria and molds, with little effect on mold spores or yeast ascospores. Certain species of Lactobacillus possess an elevated resistance to Velcorin®. 

There should be fewer than 500 microbes/cm³ at the time the dosage is added. 

According to the EU guideline EG 1129/2011 [1], up to 250 mg/l DMDC may be added to flavored non-alcoholic beverages, non-alcoholic wine and liquid tea concentrates.

Dimethyl dicarbonate (Velcorin®) quickly dissociates in aqueous solutions almost completely to carbon dioxide and methanol. In addition, small amounts of ethyl methyl carbonate are formed through the reaction of DMDC with ethanol, which can be detected through GC-MS analysis techniques [2]. The  amount of DMDC added to a beverage can be determined by measuring the content of EMC and ethanol. The Velcorin® dosage can be checked by measuring the amount of methanol quantitatively using GC analysis; however, the initial amount of methanol present in the product prior to adding Velcorin® must be determined.

H₂O + C₄H₆O₅ (DMDC) → 2CH₃OH + CO₂

250 mg Velcorin  → 119.5 mg methanol + 164.1 mg carbon dioxide

C₂H₅OH + C₄H₆O₅ (DMDC) → C₄H₈O₃ + CH₃OH+ CO₂

Since determination of the hot wort yield can be problematic and the cold wort yield as described above does not represent a measure of the total extract obtained from the grain bill, an attempt has been made to record all of the extract recovered, with the exception of that remaining in the spent grain. This value is then compared to the laboratory yield. The result is expressed as the total yield (overall brewhouse yield) (OBY_CW) in %.

After gelatinization of the starch in the adjunct, the starch is liquefied and converted through the addition of malt. Subsequently, the extract content is determined according to the procedure given in the method for malt analysis.