Bulk Grain Handling - when to switch to whole grain brewing malt and what to consider

Crisp Malt Lorry | Crisp Malt Distributors
carl.heron
Posted by
Carl Heron
on 04/05/21

Carl began his brewing career in 1987 as a lab technician at Websters Brewery in Halifax, after a short spell at Tetleys Brewery, he went back to Websters as a bottling line manager in 1990.

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As your brewery grows you’ll get to a stage where the number of bags of crushed malt you’re handling becomes strenuous and inconvenient. 

This post will explain the steps towards moving from crushed bags to whole grain brewing malt delivered in one tonne bags or in bulk into a silo. It’s a big decision with lots of factors to consider but once you’ve made the switch it will simplify your brewing malt ordering and be so much easier than humping bags of malt around the brewery.

Why switch to bulk brewing malt?

 

Pre-crushed brewing malt is only available in 25kg sacks due to the fact that the particle fractions separate during transportation. As your requirement for brewing malt increases, this means a lot of manual handling and frequent orders for malt which all takes time.

Pre-crushed malt is crushed by the maltster to work in all craft breweries and is not optimised for your brewery. The yield from the malt may be improved if milled at the brewery to suit the specific conditions there.

Whole grain brewing malt is £20 a tonne cheaper than crushed malt and if delivered in large loads could be cheaper still as it costs less for transportation.

There will be a capital outlay for the equipment but this will be paid back from the lower raw material costs and improved yields (2 to 15%).

A ballpark cost for a big bag handling system is £45k installed, for a silo system it’s around £75k.

 

When should you switch to bulk?

Product Packaging Brewing Malt Sacks
 

Bulk handling can be done in two ways. For breweries using 50 tonnes a year or more, whole grain brewing malt can be delivered in 1 tonne bags. For breweries using 150 tonnes a year or more, whole grain brewing malt can be delivered in 20 or 27 tonne loads in a trailer which is then elevated or blown into a silo.

The big bags arrive on a pallet and delivery costs around £40 per tonne, the same as a pallet of 25kg sacks. The bbags are suspended from a cradle and hoist which feeds the mill through conveyors and elevators, the crushed malt is then conveyed and elevated to a grist case ready for use in the mash tun or mash conversion vessel.

An articulated lorry with a tipping trailer is used to deliver 20 or 27 tonne loads and costs around £650 per delivery. The more malt there is in the trailer, the lower the cost per tonne of malt, so around £32.50 for 20 tonnes and £24 for 27 tonnes. The amount of whole grain brewing malt that can be delivered will be governed by the size of the silo(s) to be installed.

Silos are big, and each will need a concrete base of 4m x 4m and a depth appropriate for the amount of malt they will store. A fundamental question then is, do you have room for the silo(s)? Another consideration is the height of the silo(s), the larger the capacity, the higher they are (a 31 tonne silo is around 9metres). Most local authority planning departments will allow an outside silo height no taller than the apex of the building that the brewery occupies. If the silo(s) can be installed inside the building this is less of a planning issue but there will obviously still be height restrictions and installation will probably be more complicated unless the silo(s) are fabricated inside the building. Bespoke silo(s) are available but tend to be more expensive. Installing silo(s) outside in urban areas may not be permitted by the local authority.

To summarise ask yourself the following questions before considering moving to bulk handling;

  • Will you use between 50 and 150 tonnes a year?
    Get a big bag handling system if you have space inside the brewery
  • Will you use more than 150 tonnes a year?
    Consider installing silo(s):
    – do you have room inside the brewery for pre-fabricated silos?
    – if not, do you have room outside the brewery for silos?
    – are you likely to get planning permission to have a silo outside that is big enough for your requirements?
    – if the answer is no to all the questions above you’ll have to go for a big bag system, if you have space.
  • What budget are you working with?
    The amount you have to spend will affect your available choices:
    – the cheapest option is a big bag handling system but you won’t get the benefit of reduced delivery costs
    – the nearer the malt storage and mill are to the brewhouse the cheaper the conveying and elevating costs will be
    – buying one big silo is cheaper than buying 2 smaller ones, the choice will be governed by 2 factors;
    – can you brew the majority of your beers with one base malt?
    – will you get planning permission for one big silo?
    – the mill is one of the more expensive items in the installation, there are low, medium and high cost options. The higher the cost, the better you can control the grist fractions and the faster the mill will crush
 

What considerations need to be made when moving to bulk?

 

The most important thing to think about is space;

  • Will an articulated lorry and trailer be able to access the tipping point for the silo?
  • Is there enough space for the silo(s), big bag cradles, conveyors, elevators (height), mill (preferably in a separate room) and grist case?

The next thing is complexity, think about the brews you make and may make in the future;

  • Can you make the majority with one type of base malt? If not you might need more than one silo or big bag cradle.
  • Do you use a lot of oats, wheat, rye, flaked cereals or rice hulls? If you want to crush these through the mill, the gap will need to be reduced for grains and increased for flaked products and rice hulls. Probably best to buy wheat/oats/rye crushed and add them and the flaked stuff to a bag tip post mill, pre grist case

Once the above has been considered you should have an idea what you need for your bulk handling system and you can have a chat with your local authority planning officer about vehicle access and silo placement if necessary.

Armed with the knowledge that you know you have the necessary space and permission to install bulk handling you can start to think about the detail of what the installation might look like.

 

What equipment is involved?

 

The basic components of a bulk handling system are as follows;

  • A tip hopper and elevator to get the malt from lorry to the silo if you choose not to have it blown in (more malt per delivery plus less potential damage to the grains)
  • A malt storage device (silo or big bag with cradle) with control and shut off slides
  • Conveyors and elevators to get the malt from the silo/big bag to the mill hopper with a bag tip for whole speciality barley malts
  • A two roll malt mill as a minimum (not a barley bruiser or other agricultural mill)
  • Conveyors and elevators to get grist from the mill to the grist case with a bag tip for crushed oats, wheat, rye, flaked cereals and rice hulls
  • A grist case big enough to accommodate the largest charge of malt your mash tun or MCV can handle with control and shut off slides
  • Conveyors and elevators to get grist from the grist case to the grist hydrator with a slide to prevent water and steam ingress above the hydrator
  • A grist hydrator above the mash tun or mash conversion vessel  

The system will need an electrical control panel to house the starters for the conveyor, elevator and mill motors and any necessary air manifolds and solenoids. The latter would be used for automated slide valves on the silo(s), grist case and grist conveyor outlet. 

The conveyors and elevators have to be started and stopped in sequence to ensure that the system isn’t left with malt or grist in it. The control of this can be done manually with switches but is normally controlled with a PLC in the panel. The PLC will also be able to read load cell outputs so that you can add the correct amount of malt to the grist case.

The load cells can be on the malt storage device or the grist case, the grist case is the best option as there is less cabling. 

 

What options are available?

Crisp Brewing Malt in bags situated in the warehouse
 

We’ve covered some of the options already but let’s recap;

  • Big bag or silo system (big bag more flexible and lower in capital cost but malt is around £26 per tonne more expensive due to transport costs)
  • Big bag/Silo number, size and position to suit your specific needs with regard to space and brewing complexity
  • Silo filling – the malt can be blown in or conveyed and elevated (the latter will add around £7-10k to the project but you’ll get 29 tonnes per load not 27 tonnes)
  • Number and length/height of conveyors and elevators, the nearer to the brewhouse the bulk handling equipment is, the less the installation will cost.
  • Speed of conveyors and elevators to deliver malt to the mill and grist to the hydrator (the biggest grist should be delivered to the hydrator in 20 to 30 minutes)
  • The mill, starting prices of around £5k going up to £20k. Speed of milling should be calculated to be able to mill the biggest brew in an hour. A more accurately controllable mill should be chosen for separate MCV and lauter tun systems
 

How to get your bulk handling system

 

Hopefully by now you will have an idea of whether the possibility of bulk handling is feasible and the basics of what you would expect the facility to look like.

The next step is to talk to the experts. If you’re building a new brewery with a contractor ask them to sub-contract the bulk handling to either a bulk handling contractor or people who can supply the different components;

  • Danagri for conveyors and elevators
  • BSPS for mills, conveyors and elevators

Your new brewery contractor will also need to source load cells, slide valves, grist cases, electrical panels and PLC software specialists all of which they should be familiar with.

The last 3 companies on the list can also do turnkey installations either for your brewery contractor or for you directly if you’re adding the bulk grain handling facility to your existing brewery.

Ensure that they understand where you want the equipment and how quickly it needs to mill malt and convey grist.

Clearly explain what elements you want them to be responsible for (including any integration with the brewhouse in terms of mash thickness and PLC control)

 

What to consider during installation and commissioning

 

Once you’ve got proposals back from the people you asked to tender for the job, go through them carefully and consider everything, including the smallprint.

Cheapest isn’t always best, check what you’re getting for the money;

  • Equipment
  • Layout
  • Cabling
  • Cable containment
  • Control panel and all necessary elements inside it
  • PLC and software
  • Displays and integration into existing systems 
  • Commissioning time allowed for
  • Aftersales support, spares and servicing

Once the contractor is approved be prepared to pay an initial deposit to get them to start fabrication, if you’ve agreed some delivery timeframes (advisable) insist on them giving you regular progress updates.

Don’t forget to lay the pad for the silo(s), it’s unlikely that the contractor will do this.

As the time approaches for equipment to start arriving make sure that the areas where the elements are to be sited are clean, tidy and clear of obstructions.

Build in some brewing downtime on your production plan for final tie-ins with the brewhouse and commissioning.

Here’s what needs to happen on commissioning day 1;

  • Zero and calibrate the load cells with certified weights across a range of loads
  • Ensure that the PLC reads the same as the load cells and displays the correct amount
  • Test each of the elevators and conveyors separately ensuring they’re running in the right direction
  • Test any air operated slide valves and their limit switches
  • Set the mill to nominal gaps initially, start the conveyors manually in reverse order from the grist case to the silo or big bag cradle
  • Check that the grist case is reading zero and put a malt weight in the PLC if you have that parameter
  • Open the silo or big bag control slide and main slide
  • Go to the mill and see that the feed is sufficient but not backing up too much at the mill feedgate
  • Adjust the slide on the silo or big bag cradle until you’re happy with the flow
  • With stopwatch in hand, close the silo or big bag main slide, ask someone to make a note of the weight in the grist case at the same time
  • Go to the mill and watch for the malt running out at the feedgate, when it does, stop the timer and note down the time taken for the system to empty
  • Make a note of the inflight quantity by deducting the grist case weight at the start of the timer to when all the grist has gone through
  • The two pieces of information above will be used to calculate when to stop the flow of  malt from the silo or big bag cradle to deliver the correct amount of grist to the grist case (one thing to remember when calculating a grist case weight if the load cells are in that location is the weight of the specialty malts and adjuncts, these will have to be in 10 minutes before the milling is due to finish)
  • Once the flow of malt through the system is set a grist sample should be collected from the mill. The sample should be graded through a standard set of sieves (the mill manufacturer should have a set), a starting point of 50% coarse, 40% medium and 10% fine should be aimed for by adjusting the mill gap appropriately.

The following day it’s time to mash the grist;

  • Make a note of the time and grist weight.
  • Use a stopwatch to check the flow of grist using the load cells on the grist case if that’s possible
  • If the flow of grist can be established and the flow of mashing liquor is known, adjust either the grist or the liquor flow to achieve the desired ratio
  • Make sure that the grist isn’t backing up in the hydrator, there will be a point where it does begin to do so and this is a rate limiting step
  • Check the time when the mash is completed and if it’s a little out adjust the control slide on the grist case accordingly taking into account the point above

 

 

Final Words

 

Going to bulk whole grain brewing malt is a big decision for a brewery. It makes perfect sense when malt usage gets to the point where manual handling is a concern and malt ordering becomes onerous.

I hope that this post has gone some way to explaining how the systems work and how to take the steps to getting one installed.

Here at Crisp Malt we have supported many of our customers with bulk handling installations. There is no one size fits all for a bulk handling system, every brewery is different, so get in contact with us so we can help.

Just give the sales team a shout: 01328 829391 or email hello@crispmalt.com

 
carl.heron
Posted by
Carl Heron
on 04/05/21

Carl began his brewing career in 1987 as a lab technician at Websters Brewery in Halifax, after a short spell at Tetleys Brewery, he went back to Websters as a bottling line manager in 1990.

Read More
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