Editorial: Blending, Mixing, Pitching & Dosing

In Brewing, Food and Beverage, there is often a need to blend, mix, pitch and dose products such as powders, pastes, creams, algaes, yeasts, and chemicals into bulk liquids. These are common requirements for Brewology and we have many standard solutions which normally meet most processing demands.

Dry to Wet Mixing

Brewing typically starts with a Dry Goods to Wet Mixing process, taking grist (milled malt) and hydrating it with hot water via a Steeles Masher or a simple hydrator. This mixture then goes into a mash conversion vessel where the slurry/porridge is heated in steps and mixed to convert starch to various types of sugars. We also mix powders and pastes via a high shear mixer to produce a ready for use product called isinglass finings. This is dosed into beer as a clarifying agent, and is normally ratio blended to a recipe via a Brewology Peristaltic Pump, directly into a metered beer stream. We also have simple dosing pots which allow powders or liquids to be directly injected into a pumped product stream.

A powder / pellet dosing pot

Liquid to Liquid Blends

A typical traditional cask ale filler would normally blend in finings and other concentrated flavourings and essences via recipe controlled blending systems using various combinations of metering pumps and flow meter controlled peristaltic pumps. We are often asked to blend products such as beers and ciders to produce a blended product. This can be done as a simple batch blend, 50% of product A, followed by 50% of product B. It’s controlled by a single meter and mixed in the vessel.

Ratio Blends

The alternative is a ratio blend where we use two product streams controlled by sensors, metering pumps or flow meters. This is very common practice in modern beverage production and is used to dose a chemical such as PAA into the final rinse water in a CIP Set. Sensor blending control is commonly used to blend a liquid to a critical temperature set point from a hot and cold liquid supply. This type of blending was traditionally controlled by a modulating valve acting on one of the liquids, however today Brewology has developed pumped controlled blending where the set point is achieved by variable pump flow. This type of solution is much more reliable, accurate and cost effective compared to modulating valve technology.

A Flash Pasteuriser with Product Water Ratio Blending

Vessel Rousing & Mixing

It’s common place in food and beverage to have a uniform and well-mixed product in a vessel, whether this is simply to ensure the liquid is at the same temperature, or the product is not separated out into layers of various density. Vessel rousing and mixing can be achieved by various standard methods such as a vessel mounted rouser to physically stir the contents. Rather than just turning on a rouser, it’s often more cost effective to control the speed and frequency of stirring to recude costs and over-mixing.

Often it’s preferable to literally turn over a tanks contents by an external pump, which can transfer product from the bottom to the top of a vessel, especially when there are solids which may separate out and need to remain well mixed in. There may also be times when solids need to be left to separate out in the base of a vessel, yet the contents above still need to be recirculated. This is common to modern brewing where yeast is allowed to separate out, yet the beer above needs to be uniform and recirculated when racking or being subjected to dry hopping. In this case, the contents of a pressurised vessel is recirculated through a hop strainer to impart flavour without adding actual hop leaves and seeds.


This is a common process in both brewing and distilling when yeast is added to a wort or juice prior to fermentation. It’s often done very simply or via a blending injection process. This can be injected as the vessel is filled or added after filling. If added after, it’s often necessary to re-circulate the vessel’s product and inject the yeast / seeding into the recirculated line.

Sterile Seeding

On a recent algae growth project, it was essential to inject a seeding algae into a vessel’s sterile contents and ensure it’s also well mixed in. This was challenging but solved by standard Brewology process systems.


There are many needs through food and beverage to dose in products and chemicals into vessels and product streams. These are generally separated into very simply timed dosing when a pump or pressure pot delivers a dose via a pump or valve. This operation can be via an intelligent pump or via a standard Brewology function block. It’s often very critical for the dose to be reliable and if the dosed product can not be easily detected by a confirmation sensor, then it’s essential to link the dosing system into the main process to hold, alarm and get any issue resolved such as an empty drum of dose liquid.

When a dosed liquid can be sensed such as a caustic-based detergent injected into a dilute detergent stream/vessel by a conductivity probe, this can be used to automate detergent dosing to match a recipe set point. This is a common Brewology function on a washer or CIP Set.

The above description gives a guide to the many ways in which Brewology can deliver a process solution. We utilise modern technology, instrumentation and tried and tested software function blocks to provide cost effective standard solution assembled as integrated kits, delivered under the heading of “Fit, Plug & Play”.

We have standard modules to suit most applications and can combine modules to meet the needs of most processing plants. Rather than commission a bespoke solution, why not investigate the option to link together well-developed standard solutions, saving valuable time and expense.