By Robbie Proctor
Many home brewers are more familiar with the idea of invert sugar than they realize, through the brewing of Belgian beers. Belgian Candi Syrup is in fact an invert sugar, in this case typically refined beet sugar, that is used to increase fermentability, and indeed ABV, without increased body. Color can also be manipulated with these syrups.
There is however another brewing culture, near and dear to my home brew heart, that has employed invert sugars throughout the centuries as an adjunct, and that is British Beer.
So ‘what’s the difference between Belgian and British brewers' use of invert sugars?’ I hear you cry! And indeed, why not just use regular sugar?
Let me start with the latter.
Most of us have probably poured a pound of sugar into an American IPA, or maybe a Belgian Triple, to great effect. This sugar (sucrose) is a disaccharide. The process of inversion splits the sucrose into fructose and glucose (also known as dextrose). These new monosaccharides give the brewer a more fermentable adjunct - basically it’s even easier for your yeasties to eat!
This sounds great, but if that’s the only reason then why bother with another thing to do during a brew?
Well, increased fermentability is not the primary reason to use invert sugar, particularly in more malt forward beers, such as British Ales. And that brings us to the former question!
The English tradition of invert sugar does not use a refined product as its starting point, but rather raw cane sugar, which by its very nature contains impurities. And it’s in amongst these impurities that the magic happens.
By heating up these sugars for sustained periods of time, many small, simultaneous chemical reactions occur, producing new flavors, aromas, and colors. These are known as Maillard Reactions, and the end result is a layer of complexity in your malt forward English Beers that will have your Ordinary Bitter taste anything but!
So let’s take a look at how to make your very own Invert Sugar.
Before you start, you will need a bowl, measuring jug and a candy thermometer. After making a few batches, I upgraded from the regular $8 type to a fancy digital thermometer with a temperature probe and heat alarms!
Invert Sugar Recipe:
Sugar in the Raw (or other demerara cane sugar)
1lb sugar to 1 pint of water
1 tsp (5ml) liquid Lactic Acid @ 88% per 2.5lbs of sugar
1/2 cup (4 fl oz) light corn sugar per 2.5lbs. (Helps prevent crystals forming if you plan to store for a while)
Heat your water to boiling, then remove from heat and add sugar SLOWLY, whilst stirring.
Add your Lactic Acid, put heat on medium-high, and set a candy thermometer alarm for 230F. (Reduce the heat if you are heating more than 3F/minute)
Stir occasionally until simmering starts.
Once you hit 230F, set alarm for 240F, and slowly reduce heat to keep temp stable.
(It’s easier to slowly ramp the temp up to 240F. There is so much thermal mass, that once you go over it’s tough to get the temp back down - low & slow will also prevent any burning and associated flavors that are undesirable)
As alarm goes off @ 240F, reduce heat to keep 240F. It is ok to hit 245F, but keep it under 250F.
When am I done?
No1: 12-16 SRM (Minimum 20min @ 240F to allow for inversion, but not much longer as you don’t want color to darken)
No2: 30-35 SRM (Total of 90-120 min @ 240F)
No3: 60-70 SRM (Total of 150-210 min @ 240F)
Times are approximate. Take periodic color samples @ 10min intervals, place samples on white porcelain, and compare to an SRM chart if you want to be precise. Stop 2-3 SRM low, as it will darken a bit as it cools!
To package, I prefer a cleaned and sanitized mason jar. As the invert sugar cools in the jar, the lid will form an air tight seal. I usually make a batch a day or 2 before brew day, but it will keep longer in a cool, dark place if you package using sanitary canning procedures.
When it comes to brew day, once I have my boil on I like to put the mason jar of homemade invert sugar in a warm water bath to make it runny enough to pour. Add your invert sugar at flame out and be sure to stir well so it fully integrates with the wort. Whirlpooling helps in this process!
I have used the above method to make invert sugar for Milds, Bitters and Barleywines with great success. It really does add a little extra depth to those malt flavors, and think of the bragging rights you’ll have the next time you talk home brew with a friend. Cheers!