Brewing with Lactose


By Ryan Bailey

Once upon a time, it was commonly accepted that beer consisted of four major ingredients: barley, hops, water, and yeast.  As a matter of fact, the Germans, for a variety of reasons, enacted the now-famous “purity laws” based on the use of only these ingredients.   Now, there are plenty of historical arguments to be made that before this point, a variety of other ingredients were used in beer, including various herbs and spices, wheat, etc.  But in general, we all tend to still hold the “big 4”, barley, hops, water, and yeast, as the main building blocks of beer.
But as humans are prone to do, we can never leave “well enough” alone, which has led brewers to add all sorts of adjuncts to our beer:  the aforementioned wheat, rice, corn, various types of sugars, spices, fruit, chocolate, coffee, the list goes on and on…  But lately, with the increase in popularity of beers like pastry stouts, milkshake IPAs, and smoothie sours, one particular adjunct seems to be everywhere… I’m talking about lactose.
Lactose is a milk sugar that is found in cow’s milk.  It typically makes up around 2-8% of cow’s milk.  As far as brewing is concerned, lactose is particularly interesting and unique because it is not able to be converted into alcohol by beer yeast, which leads to it having usefulness for several different purposes:

To Add Sweetness:

If you’ve ever tried adding sugar, such as sucrose, dextrose, or Belgian candi sugar to your beer to add sweetness, you will have realized it doesn’t really work.  In fact, it generally has basically the opposite effect!  These types of sugars are often actually added to higher gravity beers to dry the beer out and cut the amount of residual sweetness imparted by the larger malt bills of these beers.  Some darker sugars, like brown sugar or molasses can be known to add some flavor to the beer, but not much in the way of sweetness.
Lactose is unique in that it cannot be fermented by beer yeast, so it can be much more effective than these other sugars if your goal is to add sweetness to your beer.  Think certain types of stouts, like chocolate or coffee stouts, to balance some of the bitterness of the roasted grains, or in fruited beers where you may want to add back in some of the sweetness that we tend to associate with fruits because most of the fruit sugars will be fermented out.

To Add Body or Mouthfeel:

Personally, I’ve primarily used lactose in stouts, which I’ve done to add sweetness, as mentioned, but also to boost the mouthfeel of the beer by raising the finishing gravity.  I love a good imperial stout as much as the next guy, but as somone in his 40s who is trying his best to be relatively healthy, I can’t always justify the high ABV and elevated calorie count of a beer that may creep into the 8-12% range.  By experimenting with lactose, I’ve made some stouts that I’ve managed to keep in the 5-6% ABV range, while still approximating some of the fuller mouthfeel of some of those heavier beers, thanks to the residual sugars and higher FG. 

To Add a Texture or Creaminess:

This is similar to mouthfeel, but I find it more related to the style or flavor of the beer than to the ABV.  I’ve personally used it with great results in coffee stouts and a Mexican Hot Chocolate stout, to impart some of that creaminess one might associate with coffee with cream, a latte, or a cup of hot chocolate.  But it’s also a very common use for lactose in beer like smoothie sours and milkshake IPAs. 

How Much to Use and When?

As with most things in brewing, there really are no set rules, other than making sure you have enough fermentables to actually make beer, but I’ve found success using lactose as about 10% of my grist, which tends to work out to about a pound of lactose for a 5 gallon batch, adding it to the boil with about 10 minutes left.  You could probably get away with adding it directly to the fermenter, but I prefer to limit any potential for contamination, so I prefer to add it to the boil for sterilization.  But experiment with timing and amounts to find out what works for you.  Lactose is less perceptibly sweet than table sugar, so unless you really go nuts, you’re probably unlikely to end up with a beer that’s cloyingly sweet.

A Note About Lactose Intolerance:

Some people lack the enzyme that allows the body to break down lactose, which can lead to a host of gastrointestinal issues that we won’t go into here (you’re welcome!).  Other people have milk allergies or lactose sensitivities due to IBS or some other issue, so if you brew with lactose, keep this in mind and be sure to let anyone you serve it to know that the beer contains lactose.  That being said, the levels of lactose in beer are usually much lower than those in milk or dairy products, so just because someone has a lactose sensitivity doesn’t necessarily mean they won’t be able to drink the beer.  For example, if I drink a milkshake, I’ll be sick for a couple of days afterward, but I have not had any problems drinking beers made with lactose, home brewed or commercial.  But be sure to give your guests the proper information and let them make that decision for themselves.
So grab yourself some lactose, open up your brewing software of choice, and have fun!

Related Products

All contents copyright 2024 by MoreFlavor Inc. All rights reserved. No part of this document or the related files may be reproduced or transmitted in any form, by any means (electronic, photocopying, recording, or otherwise) without the prior written permission of the publisher.