Big Batch Brewing Techniques

If you find yourself in need of more homebrew it is time to start brewing bigger batches. If you’re ready to “go Big,” Here is how to go beyond the basic homebrew batch size.

Brewing big batches of beer is a lot of fun and can be a great way to expand your homebrewing horizons. But it is also a BIG topic to cover. As I thought about how to approach this topic and what exactly “big batch” meant and why “going big” was the thing to do, I realized that this is all relative. Big isn’t a specific cutoff point of 10, 20 or 100 gallons (38, 76 or 378 L). Going big is really about homebrewing bigger batches than your normal batch size. Brewing big batches also isn’t a slam against brewing small. Both approaches have their rightful place in homebrewing, depending on what your goals and needs are at the time. I’ve brewed 5/10/20-gallon and 1-bbl batches throughout the years and have never thought of locking myself into a certain size. In this article I’ll walk you through reasons why big batch homebrewing is a great possibility to consider and what you’ll need to get there.

Why Brew Big?

There are quite a few reasons for brewing more beer at a time, or at least brewing more beer on occasion. Here are some of the most common reasons homebrewers scale up their batches.

Sharing beer with friends: I think every homebrewer quickly realizes that they have WAY more friends than they ever realized once word gets out that they make beer — and that they will let people drink it for free. This is especially problematic if the beer is good. I have always considered this the best part of being a homebrewer — sharing the beer and sharing the hobby. But what about when a 5-gallon (19-L) batch of beer is gone in a week? That is a little depressing.

Brewing with friends: The social aspect of homebrewing is something I never really thought about when I got started in the hobby, but it quickly materialized as a great way to meet people I normally would not have known, mostly through homebrew clubs and social events. I’ve made a plethora of new relationships through this hobby. I really enjoy sharing my knowledge with new homebrewers and I’m always appreciative of those that continue to share their knowledge with me. And when things get social in the homebrewery, you’ll need more beer. Sending a new homebrewer home with a six pack of beer samples, or better yet, their first carboy of wort, is a really great way to get them to embrace the hobby.

Limited time to brew: As my children have grown up and become more active, my work more hectic, and my home in need of more remodeling, I seem to feel compelled to drink more beer. But all of this is, of course, inversely proportional to the time I have available to brew said increase of beer. So peeling away time to brew frequently is a challenge. Could I ask my wife, “Dear, will you clean the kitchen and run the kids to soccer and get groceries while I work hard and brew beer all morning?” There is no good way to put a positive spin on that question. But brewing a double batch of my favorite beer takes little more time than brewing a single batch. I also find that if I run out of my wife’s favorite IPA (Bell’s Two Hearted clone) she gets a little less tolerant of my quirks and unending hobbies. Let’s just leave it at that.

Experimenting with different yeasts and ingredients: Now that there is a tremendous variety of homebrewing ingredients, techniques and knowledge than there ever have been, experimenting is a very alluring prospect. Brewing a single beer wort with a variety of hops, yeast or special ingredients is a great way to grow your knowledge and sensory perception of what these ingredients do, and how you can dial them in to create your special brew. Brewing a big batch of wort and splitting it into several carboys for yeast and special ingredient experimentation is perfect. If you’re experimenting with boil techniques, you can split the mash into two or more kettles. The list of experimentation is virtually endless, and a big batch of beer can be divided many ways. The advantage of starting with a large base wort is that you eliminate one variable (the base wort), which lets just the experimental variable (yeast, hop, technique, etc.) shine through. This is especially great if you brew with a buddy or a homebrew club — brew one big batch and everybody gets a few gallons or liters (read on).

Parties and events: This is yet another aspect of big batch brewing I hadn’t anticipated — masses of thirsty people. My family has an annual New Year’s party and it is a great way to share my passion for home-crafted beer and wine with all my friends and co-workers. It’s that time of the year that I brew double-size batches so I have enough beer for the event, but also have some left over to enjoy later. I’ve also learned that one can garner a LOT of charitable donations through homebrewing. Doug Granlund, my good friend and VP of Operations at Blichmann Engineering, and I brew for regular events, including raffling off “Brew with John & Doug” for a day, to auctions where we’ll put on a tasting and design and brew a beer for a group of winners. We also do beer-tasting events at local pubs where we pour samples of our homebrew for attendees. Let’s not forget club events and beer fests — club night at the National Homebrewers Conference, anyone? All of these gatherings benefit from big batch brewing.

Club brewing and equipment sharing: When I started brewing I really hadn’t thought much about the benefits of brew clubs, but they were something I quickly learned about and grew to really appreciate. Hands down, this industry would not be where it is today without the homebrew clubs and retail stores that support the hobby. Currently my meddling kids and their non-stop activities foil my attendance at most Tippecanoe Homebrewers Circle club meetings here in Lafayette, Indiana. But I am looking forward to getting back into meeting regularly and doing some of the fun things I’ve seen other clubs do — which includes helping to start “Big Batch Day” where we get the club together and brew a giant batch of beer together, splitting the batch for members to bring home and ferment. Not only is big brew a great social event and super way to attract new members, it’s an awesome way to pool resources on equipment, brew more economically, and most importantly share knowledge about brewing.

Thinking of going pro: Big batch brewing is also a great way to dabble in the art of commercial brewing. There is a big difference between brewing for a hobby and brewing to make money. Brewing for money is hard work, and brewing big batches is a great way to experiment with whether or not you want to go pro. You’ll get a hands-on glimpse of working with big equipment, as well as handling things like yeast propagation and quality control.

Batch Size and Equipment

I’ve talked a lot about brewing multiple size batches in my travels for Blichmann Engineering, and I am frequently asked about batch size and what equipment makes sense. The key to leveraging your equipment is flex-ibility and adapting to some compromises. If you aren’t sure what size batches you will brew most often but you know you want to brew big, the best thing when you are buying equipment is to go larger than smaller. You can under fill a pot, but not the converse. If you want to do an occasional smaller batch on your big equipment, you can switch out your biggest kettle and make it your hot liquor tank (HLT). For your mash you will want to pick the pot that gives you an adequate grain bed depth (at least 6 inches/15 cm) and use a thinner mash to make sure you reach your thermometer for temperature monitoring. This is the most critical vessel. Having a low level in the boil kettle isn’t that big of a deal, but you will get a different boil off rate and larger losses than a smaller kettle. A little more water and a couple pounds of grain solves that handily.

Equipment to Brew Bigger

Once you’ve committed to go big it’s time to put it down on paper. Create an equipment list and start a brewery layout drawing. Here is the stuff you will need:

Pumps: There are a nice selection of affordable pumps on the market today. And any batch of homebrew over 5 gallons (19 L), in my opinion, requires a pump. Yeah, you may be able to man-handle a 90-pound (~40 kg) pot of boiling wort, but the risk of burns or a back injury aren’t worth it. If you’re homebrewing more than 10 gallons (38 L), you’ll unravel some important organs in your body trying to move it. Get a quality pump and it’ll last for years. There used to be a lot of concern about sanitation with pumps, but time has shown that it was worry, not a reality. Be mindful of sanitation and you’ll be fine.

Heat source: You’ll definitely need a properly sized burner or electric heating element to get things heated quickly and have enough power to generate a solid boil to drive off dimethyl sulfide (DMS) and isomerize those delicious alpha acids. See the chart on page 59 for recommended power levels to get the job done properly. But note that gas and propane burner efficiency ranges are all over the place, and manufacturers ratings are not usually very accurate. In general, you’ll want a higher end homebrew burner for 10 and 20 gallon (38 and 76-L) batches. For one-barrel (31 gallons/117 L) batches, a commercial stockpot range is ideal for extra power and also to safely support the weight of the pot. Hand-built frames with jet burners are also a good choice.

Kegs: Kegging is a must for big batch brewing in my opinion. Bottling a couple of cases for a 5-gallon (19-L) batch of beer isn’t a major deal, but bottling 100–200+ is extremely time-consuming and takes up a lot of storage space. If you want to share some homebrew in bottles you can easily transfer some sediment-free beer into bottles or growlers as needed. Kegging systems have really dropped in price and are one of your better investments, or you can always make your own kegerator.

Fermenters: While carboys will still get the job of fermenting done with a large batch of homebrew, managing two, four or more carboys at a time can be a lot of cleaning and racking. This is the time to consider the value of a conical fermenter. Not only can you get the job done in one vessel, you can also have the ability to easily harvest yeast, which can save money and time (no more yeast starters) if you use that yeast frequently. Taking samples is also a breeze. There are a number of other bulk tanks available, but in my opinion you should be very cautious about plastic tanks to make sure they are food grade, oxygen impermeable, and that the fittings and valves can be fully disassembled for cleaning. Cooling your larger batches while fermenting needs to be carefully considered but does not need to be elaborate. If you’re brewing ales and have a room with moderate temperatures (65 °F/18 °C or less) you’ll be able to ferment up to 30-gallon (114-L) batches without external cooling using a stainless tank. Expect about 5 to 10 °F (3 to 5 °C) rise over ambient temperature in a fermenter in the 20- to 30-gallon (76 to 114-L) size. A wet blanket placed over the fermenter will take the temperature edge off of an aggressive fermentation. For lagers, and the ultimate in temperature control, consider investing in a large upright freezer (about $600 new). Adding a temperature controller will let you dial in the exact temperatures and it makes a great place to store finished beer. We cover the conversion details for that project on the web page. Or, if your wallet allows, a thermo-electric cooling system is pretty awesome too. Many small commercial breweries I’ve seen have simply made a “cool room” using a window AC unit. Be a little creative and you can get the job done for a reasonable price.

Chillers: Cooling a big batch of wort is obviously not as easy as cooling a small batch. However, there are great products such as plate chillers that get the job done quickly. Your simple immersion chiller will work for 5- and 10-gallon (19- and 38-L) batches reasonably well, but a 20+ gallon (75+ L) batch really benefits by using a counterflow chiller (tube in tube, or plate type) and a pump. You’ll save a lot of water and get your wort cooled quickly. Choose a product that will chill your full batch to pitching in about 30 minutes or less.

Before You Go Big . . .

There are, of course, some drawbacks to brewing big, and one of them is equipment cost. If you are patient then you can scour used restaurant supply stores for used commercial cooking gear, but be prepared to do some modifications to the equipment yourself. The other drawback is space. Bigger equipment takes up more space, however it does not take up double the space. I brew up to a barrel (31 gallons/ 117 L) in my indoor 9-foot X 15-foot homebrewery. The key is mobility of the equipment and organization of your brew space.

While there are a lot of advantages to big batch brewing there is also a risk: One mistake can wipe out a lot of beer. But with the knowledge, equipment and ingredients out there today that risk is certainly manageable. In the dark days of homebrewing, nasty homebrew (AKA “dumpinbrau”), was somewhat common but not anymore. So don’t let that risk sway your decision. The reality is you’ll focus even more intently on sanitation and your process, and you’ll likely end up with even better beer than your small batches.

Go Forth and Grow

Big batches definitely offer a lot of advantages, but don’t get hung up on always having to brew the same size batch every brew day. Be creative, learn to adapt your equipment, and you’ll always have plenty of fresh home-crafted beer on tap for friends and family to enjoy.

Scaling Up

If you want to start brewing larger batches of homebrew, it’s tempting to simply double (or triple) the ingredients in a recipe to achieve the large-batch results. It’s not quite that simple, however. Scaling up is not complicated but to do it right requires a little mathematic manipulation. This is because the efficiencies of small and large brewing setups are usually different, and small differences in ingredients can make a big difference when scaled up. Differently shaped brew kettles and heat sources can also affect the beer when you try brew it on a larger system.

The most important information to know before scaling up is the efficiency of your brewing setup. There are a few different ways to find out that information, but Brew Your Own’s Mr. Wizard, Ashton Lewis, recommends figuring this out by simply comparing how much extract you produce during wort production to the weight of malt you use. His advice is as follows:

“For example, let’s assume that I produce 20 liters of 12 °Plato wort and used 3.4 kg of malt in the process. My extract yield is equal to (liters wort)*(decimal equivalent of °Plato)*(equivalent specific gravity to Plato). You can convert Plato to specific gravity using the following formula:

Specific gravity = {Plato/(258.6-([Plato/258.2]*227.1)}+1

Once you determine that 12 °Plato is equivalent to 1.048 SG, the rest of the calculation is easy. I have included units below to show how the units cancel, resulting in kg of extract:

(20 liter)*(0.12 kg extract/kg wort)*(1.048 kg wort/liter) = 2.52 kg extract

The 2.52 kg of extract represents what was extracted from the 3.4 kg of malt during wort production. When 2.52 kg is compared to 3.4 kg the result shows that 74% of the malt added to the mash ended up as extract in the wort.”

So, if you run the numbers and find that your brewhouse efficiency is, say, 65%, you can adjust the malt bill of the recipe using the efficiency of the original recipe. Let’s say the efficiency of the system for the original recipe was 75%. In this case you would multiply the malt bill by 1.15 (the number 1.15 is the two efficiencies divided: 75 ÷ 65). Brew Your Own, by the way, standardizes all of the recipes that appear in the magazine to a 65% extract efficiency.

As for hops, scaling up for homebrewers is more of a guessing game as there is no easy way for us to calculate the iso-alpha-acids in finished homebrews. When you scale up a homebrew recipe, simply scale up the amount of hops with simple multiplication and use your sensory perception to tweak the recipes when you go big.

Of course, if you don’t want to do the math you can use any of the various brewing software platforms available to homebrewers (BeerSmith, BeerTools, iBrewMaster, etc.). A good brewing calculator or spreadsheet is your best friend in the homebrewery.
~ Betsy Parks



Issue: October 2014