A question I get asked a lot is “what information is needed when contract brewing”. When helping people connect with a host brewery to make beer at their facility.
Note: For a PDF copy of this article, please click this link and download the guide from my Google Drive.
I’d like to share what I’ve learned over the years. So, you can be more prepared when you go through the same process.
Granted I’m generally helping people looking to brew in China and making 10,000-liter batches or larger. However, whatever size of the batch the principles are similar.
The first place to start is the beer recipe and processes…so, this is where we’ll begin.
Please note: We can’t cover every possible aspect, when it comes to contract brewing. What we’ll do is explain the main parameters host breweries expect. Plus, what you need to provide. In the hope it’ll help you at the start of your contract brewing journey.
Beer Recipe and Matrix
The host brewery will need to tell you their brewhouse efficiency, what levels of isomerization they expect from their brewhouse. Plus, their water profile, if not using RO water.
This will allow you to put a recipe together, knowing the amount of ingredients you’ll need to hit you target metrics. Such as:
IBU target – How bitter you want the final beer going in to the fermentation vessel (FV)
Original gravity (OG) – The initial Plato/specific gravity of wort going into FV
Final Gravity (FG) – Ideal target gravity (Plato/Specific gravity)
Color – Ideal color, you’re hoping from the brew using something like the SRM beer color scale.
CO2 volumes of the packaged product – Maybe different depending on pack type (keg/bottle/can).
Target % ABV – A calculation based on the OG and FG
Water treatment – What’s needed and the chloride to sulfate ratio
These are some of the main parameters you’ll need to share when giving a recipe to a host brewery. So, from the outset they’ve targets to hit, based on the recipe and brewing process given.
If you’re looking for some tips on how to put a beer recipe together, please read our in-depth guide here.
Raw Materials – What Information Is Needed When Contract Brewing?
When putting a beer together, the guest brewer will need to list out all the raw materials they need for the brew.
This is everything from water treatment through to brewing aids. Which should be put into the beer, just before packaging. For example, “Hop Haze”.
When doing a first brew at a host brewery, it’s always good to check with them. If they think the recipe and processes are correct. Thus, allowing the target metrics to be reached by the host brewery staff.
The guest brewer will be buying the ingredients and coordinating with the host brewery to have these materials sent direct to the facility.
It’s worth asking if you can buy water treatment and other ingredients like Irish moss from the brewery. As the quantities maybe small, most host breweries will able to accommodate this.
However, main items like malt, hops and yeast will be bought by the guest brewer. Some host breweries allow you to buy brewing ingredients from them.
However, it’ll often work out more expensive. Still, it’s worth looking into this option, just in case. Easier logistics, but likely more expensive.
If doing larger batches, then speak with the host brewery, as they often will provide yeast propagation services for a lower fee than, having to buy a direct pitch.
This however, has to be agreed upon in advance. So, the yeast can be prepared in time for the planned brew day.
When mashing-in, a brewer needs to provide all the metrics such as:
Volume of water to add and initial target mash temperature – This will factor in the liquor-to-grist ratio. Worth checking with host brewery if the target metric is good for their system and the beer being brewed.
Water treatment – What brewing salts and acids are to be added
Mash pH – Ideal target mash pH, conferring with the host brewery, how much acid may need adding. Plus, which acid you’d prefer to use. Lactic, phosphoric or maybe even citric.
Again, this acid could possibly be purchased off the host brewery. As the quantity maybe small. With the brewery likely carrying the acid you need.
Step-mashing – Is there’s a step mash routine, if so at what temperatures and for how long.
Vorlaufing – How long you’d like to vorlauf to ensure the wort is clean (without malt leak) before sending to the brew kettle.
Mash off temperature – If the host brewery has the ability to heat the mash. Then a guest brewer may want to raise the temperature of the mash to 76°C, before starting the vorlauf.
Lautering Process – What Information Is Needed When Contract Brewing?
The process flow of a brew day, obviously depends on the brewhouse. The brew day will be different on a two-vessel system as compared to a four-vessel system.
Still the wort will be need to be “vorlaufed”, till it’s clear and the guest brewer happy to begin sending wort to the brew kettle.
Boil Off Rate, and Pre-Boil Target Volume and Gravity
Hitting final gravity target is based on typical boil off rate, and how long the boil is planned for. So, before the brew day, check with the host brewery if the pre-boil gravity is fine for their system.
As well as the target pre-boil volume estimate, to hit original gravity after boil. I like to always state what sparge water temperature I’d want. Some breweries have slightly different ideas on this.
What you don’t want is for the sparge water to be too hot, and lead to astringency in the final beer. So, stating desired sparge water temperature yourself, will stop any confusion.
It’s okay to state you want a slower and gentler lauter too, within reason. I always state, I’d like lautering to be at least 90-minutes long. Of course, this depends on the system and beer style too, somewhat.
Please note: If using a lot of adjuncts for example, over 50% of the grain bill is wheat. Check whether you need to add rice hulls or another enzyme to help with the lautering.
Tracking the pH and Gravity of the – What Information Is Needed When Contract Brewing?
When it comes to wort pre-boil volumes, most brewers like to keep track of the pH too. Ensuring the pre-boil pH is within a specified range. Dependent on the beer style being brewed.
Furthermore, it’s always good to have gravity and pH of the running’s to the kettle checked and recorded on the brew sheet. Done at regular intervals throughout the lauter. So, if there are any issues later, where the problem may have arisen can be tracked.
Towards the end of the lauter it’s good to check the pH and gravity of the wort, again. Especially with lower abv beers. As you don’t want to pH to be too high (above 5.9 pH) or the for the gravity to becomes too low, below 2.0 °Plato (1.008).
As this may again lead to unpleasant astringency in the final beer. Each brewer will have their own parameters and the ones I list are only a guidance. Based on what I and many of brewing friends prefer.
Extra Note – Lowering Mash pH
What I’ve been studying recently for smaller abv beers (3.5% and below). Is to lower the mash pH to around 5.1, as a good target to reach for.
It seems low to some, but research suggests you can go as low as 1°Plato (final running’s), without pulling any astringency. Plus, of course the running pH will be lower naturally, too.
Sparge Water – What Information Is Needed When Contract Brewing?
Before the first contract brew you need to check what type of sparging the brewery has. It can be continuous (fly) sparging, which is more common in the UK.
The other option is “batch sparging”, when a volume of water is added during the lauter. For example, 100-liters of sparge water added at a kettle volume of 400-liters is reached.
Whichever option the brewery uses; sparge water amounts and timings need to be agreed with the host brewery. Check with the host brewery and seek their guidance on best practices for their system.
Water treatment note: Some brewers like to add additional salts needed during sparge, direct to the kettle. If the guest brewer wants to add additional salts after the mash. This needs to be communicated to the host brewery.
The boil parameters to be set out and agreed are generally as follows:
Pre- and post-boil volumes and pH – The ideal of each based on the brew being done (see also boil length)
Total IBU’s – Target bitterness of the beer; check with the host brewery for accuracy. Plus, agree on amounts of each hop variety to add and when.
Boil length and boil-off rates – So, the target original gravity can be reached. Boil-off rate should be a minimum of 5% at least. Average boil off rate for a 60-minute boil is between 6 and 8%.
Addition of yeast nutrients, kettle finings and any other adjuncts – What to add, how much and when.
Another point to consider is to check the gravity in the last 5-minutes before the end of the boil and the aroma hops are added. To see if the target post boil gravity will be reached.
If it looks low, then you may need to boil for longer (which may impact IBU’s, depending on the hop additions previously).
If the gravity is looking high, then water may need adding. Which again can affect IBU’s. It’s a call every brewer needs to make, but for me hitting target gravity and pH is paramount.
A brewery needs good venting so the steam can escape the kettle. You don’t want the steam condensing and dropping back in the wort.
As it’ll lead to DMS in the final beer. You don’t want your beer to taste like sweetcorn!
The most basic way is to keep the brew kettle door open, if using a very basic set-up. Otherwise, the kettle should have a flue to the outside, or some form of condensing unit.
Dip hopping note: If you want to DIP hop, then again discuss this with the host brewery.
The Whirlpool – What Information Is Needed When Contract Brewing?
Speak with the host brewery about ideal process and how many minutes they recommend whirlpooling for. It may mean adjusting a recipe slightly.
A brewer wants to ensure there’s nice tight hop/trub cone in the whirlpool. So, clean wort is being sent to the FV. Also, worth checking the brewery has a hop strainer before their heat exchager too.
When it comes to the addition of whirlpool (WP) hops, check if the brewhouse has the ability to cool the wort, before adding WP additions.
Ideally these days with most modern brewers, they want to add their WP hops at 70 to 85°C (158 to 185°F). Depending on the beer and personal preference.
If the brewery doesn’t have this cooling ability, then the recipe will need to be adjusted accordingly. Whatever the case, this all needs to communicated and agreed upon before brew day.
So, length of whirlpool, hop additions and whirlpool temperatures are the key points here. Ensuring a tight cone is achieved too.
Wort Collection to Fermentation Vessel
When it comes to collecting the fermentation vessel the main parameters are:
Wort aeration – Do you want it? In most cases yes, but when I’m brewing a wheat with fresh dry yeast. I don’t like to aerate the wort, it’s personal preference.
Furthermore, what level of wort aeration do you want? I typically target 12 to 17ppm when it comes to wort aeration.
Wort collection temperature – Based on temperature the yeast used, likes to ferment at. I like to collect 1°C lower than the temperature I’ll set my FV to.
Yeast pitching – Many breweries pitch the yeast during the wort collection. It’s best to wait for the wort temperature to have stabilized, before adding the yeast.
Once the collection has finished, then make sure, if possible, the fermentation is closed from the elements.
It can be as simple as the CO2 outlet going into a bucket of water with some form of sanitizer in it. As seen in the picture above. Each brewery will have their own way of doing things.
Fermentation Profile – What Information Is Needed When Contract Brewing?
Fermentation instructions and overall cellaring, is as, if not more important than the brew day, for me.
Furthermore, the day after brew day, I like to dump some trub from the bottom of the FV. Which may have accumulated and settled, but ensuring no yeast is dumped.
As we move further in to fermentation, I think it’s be best to break-up the topic into smaller sub-categories.
I’ve put these in no particular order. Plus, I can’t cover all possible instructions needed to give a host brewery, but will certainly cover the main areas needed.
Temperate Throughout Fermentation
When brewing some beers styles, modern lagers in particular. The fermentation temperature will need changing, at certain points during attenuation.
For instance, when using a lager yeast strain like Fermentis W-34/70, at about 55% attenuation, I’ll increase the fermentation set temperature.
For example, if I’ve been fermenting at 12.5°C initially. I’ll let the fermentation go to around 18°C, once 55% attenuation has been reached, to help clean up the diacetyl.
Some brewers will heat up in stages. So, take the wort up to 15°C first, and then onto 18°C later, it’s really up to personal preference. Noted the heat is provided by the exothermic reaction of fermentation alone.
Spunding – What Information Is Needed When Contract Brewing?
The most popular and read article on my site is on spunding beer, so get the complete guide to here. I’ll keep this brief, as you can read all about spunding on the main article. Spunding helps save on CO2, as it allows brewers to capture CO2 produced by fermentation.
You’re “naturally carbonating the beer”, which I believe it leads to smoother carbonation and better head retention. If you plan to dry-hop; then you can’t spund until dry-hopping is completed.
Otherwise, you can end up with a dry-hop volcano, or lose head retention due to CO2 breakout. Plus, it dangerous too!
When to spund, and at what pressure to set the valve at, is personal preference of every brewer, from their experiences. If a guest brewer is unsure, they can always ask the host brewery for guidance.
Again, it depends on the process the host brewery uses, be it using a hop cannon, other dynamic dry-hopping methods, or employing static dry-hopping processes instead.
A guest brewer will have their personal preference. So, guest and host brewer need to agree on a method which works for the client, and to be carried out in the host brewery.
So, the host brewery understands and agrees to the process. It’s not something you want to argue about once the wort is in fermenter.
Hop amounts, process and at what point during cellaring dry-hopping takes place, needs to be stated, agreed plus, written down. So, everyone is on the same page.
Same as with dry-hopping…process, amounts and timing need to be agreed upon. Do you want the puree added to be fermented out for instance? If not, then the beer should be pasteurized to ensure a stable product is sent to market.
Puree (with its sugars) added post fermentation could ferment in the packaging. Leading to exploding cans and drinkers being injured as a result.
VDK Rest – What Information Is Needed When Contract Brewing?
Diacetyl which presents as butter flavor in final beer, if the levels are too high. It’s a big no-no, for most styles. It’s acceptable at low-levels in some beers, like Czech pilsner.
So, before a beer goes on chill, VDK numbers need to checked. As a general rule of thumb, I like to have the majority of my beers below 0.6 mg/L, before putting it on chill.
One Step or Multi-Step Cooling
Some brewers believe, especially when using dry ale yeasts, beers will flocculate (clear) better naturally, when stepped cooled.
So, after the VDK check is good, set the beer to 10°C for 48-hours, then to 5°C for 48-hours before taking to the final cellar maturation temperature. Usually between 0 and 2°C.
Other brewers will simply take the brew down to desired terminal temperature straight away. Again, it’s personal preference. Whatever a guest brewery favors, it should be communicated to the brewery.
A lot of what I write here will be the same as during fermentation. Lagers generally needs to mature longer than ales.
During maturation you want to get close to your desired CO2 level. If you’ve not achieved CO2 target during spunding.
I’ve got a guide to carbonation levels for different beer styles here, on my site.
Yes, inline carbonation exists, but in my experience most OEM/host breweries don’t have this option.
Beers can be regularly topped up with CO2 to the cellar tank head space. So, the beer naturally picks-up carbonation over time. The other option is to use a carbonation stone, which allows a brewer to carbonate a beer in a matter of hours.
For our full article on fermentation for a deeper understanding, our in-depth article is here.
Unitanks – What Information Is Needed When Contract Brewing?
In modern brewing, breweries use unitanks, where the beer is fermented and matured in the same vessel. Often the beer is also packaged direct from the same tank too.
Most host breweries want to “turn” beer as quickly as possible. Meaning they want the guest brewer’s beer, to be packaged as quickly as possible.
Generally, host breweries will have a time limit on how long beer can be in tank. For example, 25-days is allowed, as part of the agreed contract.
If the beer needs longer, then there’s a daily fee for every subsequent day the brew is in tank. Some unitanks, have carbonation stones. If the beer is needed quickly, then the stone can be used to get the beer to the correct CO2 level.
If you have some time then, slowly topping the pressure to the desired carbonation level is reached, can be an option.
It’s something both the guest and host brewery can discuss and agree on. With slower method it does mean more CO2 testing, which the host brewery may not be happy with.
Filtration, Separation and Finning
Depending on the options at the brewery, and guest brewer preference. An agreement has to be reached, on how to clear the beer, or reach a target turbidity.
Target turbidity could be centrifuging a NEIPA (New England IPA) to agreed EBC, then dosing with hop haze to have a consistent “haze” throughout the shelf life of the beer.
If a beer needs to be cleared, then a process has to be agreed upon, before the beer is brewed. For example; if a beer is to be ran through a centrifuge (and possibly downline filters) or through a DE filter
Then the guest beer will be charged an extra fee accordingly. Plus, another vessel will be used for the now cleared beer to be stored, ready for packaging.
After the beer is cleared, then the onus is generally to package the beer as quickly as possible, as long as the carbonation level is within agreed parameters.
Adjuncts, Fruits and Other Cold Side Additions
If a beer needs additions in the unitank or post separation, this again needs to be settled upon before brewing.
The most common cold-side addition in brewing is dry-hopping. When during fermentation the hops are added to the unitank, to add more aroma to the final beer.
The guest brewer needs to be clear; what varieties are being added, how much and at what point of attenuation the hops are to be added.
If more than one addition is required. For example, if you see “DDH”, it means double dry-hopped. Meaning hops were added into the fermenter two different times. You can triple or even quadruple dry hops.
However, many additions are to be added, this all needs to be clear before brew day with the host brewery. Furthermore, if there are any extra steps needed when dry-hopping, make sure this is all clear as well.
For example, if a guest brewer wants to dry-hop at a lower temp, after a yeast dump and then rouse the hops daily during dry hop, this all needs to written down a made clear.
Also, how long the guest brewer wants the hops in the beer; before being dumped. Generally, 3 to 4-days. So, the hops don’t start to impart a “vegetal” note.
Other Additions – What Information Is Needed When Contract Brewing?
Pretty much anything is added to beer these days. Obviously, fruit is a popular one, but if the ingredient is more unusual then the Milk the Funk (MTF) Wiki is a good source of information about process and dosing rates.
Likewise, the MTF Facebook group is a great place to discuss different ingredients, if you want some extra advice, or seek out other people’s experiences.
Whatever ingredient, adjunct or brewing aids a brewer intends to use cold side, the process needs to be clearly set out.
For example, I used to be production manager at a brewery in Armenia, called Dargett. Armenia is a famous in the region for its apricots.
Adding Fruit Puree to Beer
We made a wheat-based beer, to which we added apricot puree too. Our process was written out and the brewing staff and I followed the SOPs religiously. The instructions used, I’ve simplified and shared below:
1. At 1.5° Plato before target terminal gravity add 440Kg (2-drums) of Apricot to the double batch brew. Using a self-priming centrifuge pump.
2. Recirculate to mix the beer and puree for 30-minutes.
3. Allow the beer and added puree to ferment out.
4. Normal cellar practices of crashing once all parameters are in target and dumping of yeast.
5. Push the beer from FV to BBT. As we found if we packaged direct from the FV, we’d get some stratification. So, some bottles when packaged, had more puree in than others.
6. Check the beer is carbonated correctly and ideally package within 24-hours of the beer transferred to BBT.
Obviously, the instructions we had internally were more detailed than this. As would similar directions from a guest brewer to a host brewer. However, it shows the general idea of communicating cellaring instructions to a host brewery.
Packaging – What Information Is Needed When Contract Brewing?
So now the beer is ready for packaging. All targets are within parameters, including carbonation. If the beer is partly kegged, with the rest going to either bottles or cans.
Then the kegged beer may be at a lower carbonation point than for cans/bottles. If this is the case, then it makes sense to hit you kegged CO2 volumes, and package into kegs first. Then increase the carbonation level, to package the rest of the beer.
Before brewing; how the beer is to be packaged; should have already been agreed. So, all packaging materials should be in the brewery ready to go. Or kegs cleaned, purged and ready-to-fill.
With packaged beer, the main concerns are the DO and TPO numbers. To get true results, the beer needs to measured as soon as possible after the beer has been filled.
For many, the Anton Parr CboxQ is the go to instrument for measuring DO and TPO. Please see the box below for what’s considered the industry standard oxygen levels throughout the brewery.
Packaging and Warehousing Costs
When it comes to packaging costs, the guest brewery pays for all the packaging materials. It’s the same as with brewing raw materials.
They need to be sent to the facility in time for the packaging run. All packaging has to be in accordance to local regulations. So, the beer leaving the brewery is fully legal.
Costs of physically packaging the beer will either be one complete charge for the brewing, cellaring and then packaging (kegs, can or bottles). Otherwise, the brewing and packaging is counted as two separate services, with their own fees.
Furthermore, if a guest brewery needs to store their beer for some time in the host brewery, after packaging. There’ll likely be a warehousing fee too.
The costs of brewing, cellaring and packaging in a host brewery, are generally standard and a price list already existing.
It’s only if the guest brewer needs extra steps/processes, where fees need to be negotiated. For example, of if the bottle needs a wax dipping.
As shown in the picture here, courtesy of Crafthead a lovely Chinese brewery/cidery who make absolutely beautiful brews.
Delivering and Secondary Warehousing
After warehousing all costs are on the guest brewer. If beer needs to be delivered to a guest brewers’ warehouse, then they need to organize and pay for it. A host brewery can perhaps help find reliable transportation if needed.
Likewise, if beer is going directly to client, then the guest brewery needs to organize shipment and cover costs. Once the beer leaves the brewery, it’s the sole responsibility of the guest brewery.
Unless there’s an issue with shelf life, an infection or other issue. Then discussions need to take place with host brewery.
Liability issues due to bad product should be covered somewhere in the contract already agreed between both parties however. …and there we have it, “What Information Is Needed When Contract Brewing?” done.
What Information Is Needed When Contract Brewing? Conclusions
This turned into a beast of an article. I’ll level with you; I started this 6-weeks ago! I thought I might never finish it, and at times made me crazy.
However, I hope finally getting to the end and publishing this, allows some readers to get helpful insights, valuable to them when contract brewing themselves.
I think there’s also decent general brewing advice in here too. As I’ve shared a lot of brewing knowledge, I’ve learned over my 25+ year brewing career.
If anyone has feedback to add, feel free to comment below. If you have some more in-depth questions, then feel free to email me. My contact details are below.
Note: For a PDF copy of this article, please click the link, it’s a Dropbox link.
Need Help with Contract Brewing? Then Get in Touch
I’m now using this experience to help breweries (domestic and overseas) brew in mainland China with contract breweries here.
China is a huge beer market, and foreign breweries look to brew their brand and sell locally. I can help companies find the right local brewery to fit their needs.
Also, people are brewing their beer in China (where I’m based) and selling overseas. For example, I’m in discussions with one company looking to brew in China, and sell to a European country.
I’ve found them a brewery with competitive rates. Plus, has train tracks right outside the brewery, which are connected to Europe through the Belt and Road policy.
Looking for advice on contract brewing either in China or elsewhere. I’m also discussing a project in India currently too.
Then please feel free to get in touch. I’m always happy to have a chat and talk about your project.
My email address is:
Or you can scan the relevant QR code to add me to your preferred network, and message me there directly.