I bought a SodaStream and soon started wondering whether I could make my own syrup. I quickly discovered that I was not alone and that there were several very good books out there to help me get going.
This is actually a review of three books about making your own soda. I got all three books out of the trusty Baltimore County Public Library and had a wonderful time experimenting.
The Artisan Soda Workshop: 75 Homemade Recipes by Andrea Lynn
This is the best book for those looking for recipes for syrups to put into their SodaStream bottles for two reasons: the syrups are pretty good and the concentration is right. They recipes are typically 1.5 to 2 tablespoons per 8-10oz glass, so you will need ½ cup of syrup at the very most to work with the SodaStream 1 liter bottle - which is just perfect. Neither of the other books create syrups that have the right concentration. Indeed, this book is design for SodaStream and the author lists SodaStream as one of the essentials. The author is not affiliated with SodaStream. The book covers all the basic syrups and uses a variety of different sweeteners, picking the one that she most feels complements the recipes. As others have noted, this book is small, but that is just fine. When you only have a few ingredients on a page combined with some pretty basic instructions, you don't need to kill the trees. Two minor issues with the book: no index and no resources section. This book does not contain any information on fermentation for those interested in self-fizzing sodas.
Homemade Sodas: 200 Recipes by Andrew Schloss
This the best general book on making sodas, but not the best in any particular category, although it is the only one with a recipe section for using sodas in regular cooking. You can make syrups and learn about using fermentation, and there are recipes, including the famous seltzer matzo balls. Nice index and helpful section on resources. There is also a comprehensive introduction to soda making and good information on sweeteners. For those using a SodaStream, the concentration will not work with your SodaStream bottle, but, of course, you can just put syrup into a glass and add seltzer. Unfortunately, there are some clunker recipes, and I still have nightmares about the Date + Balsamic Vinegar experience.
If you are only looking for SodaStream, go for the Artisan Soda Workshop; if you are only interested in fermentation, you might want to look at True Brews: How to Craft Fermented Cider, Beer, Wine, Sake, Soda, Mead, Kefir, and Kombucha at Home by Emma Christensen; if you are looking for the best soda syrups available, then head for the next book, by Anton Nocito.
Make Your Own Soda by Anton Nocito
This book is in a different league to the others. This chap is the soda-maker royal to Martha Stewart! This is the put ice in a tall glass, add 3 tablespoons of syrup (plus a tablespoon of lemon juice or a dash of this or that - depending on the recipe), add seltzer, kick off the shoes and relax book. Wonderful index and resources. Here is an example of why this book is in a different league: The cream soda in the Lynn and Schloss books consists of just vanilla beans, water, and sugar. In the Nocito book, that basic recipe is called vanilla soda. Nocito's cream soda includes boiling sugar in lemon water to caramelization before adding more lemon water, the vanilla beans, and a dash of salt.Wow! What a difference! I am still on the fence as to whether or not to buy this book because I really just need syrups for SodaStream. (I bought the Artisan Soda book). I suspect that the lure of such great sodas will be too much for me and I will eventually give in an buy this book.
Just a quick warning before you run off to try to make your own syrups: Cola is very, very complex, and you will not be able to reproduce Coke. Root beers are also very complex, with lots of ingredients. With such complex syrups, the effort may be more than it is worth. If you are going for cream/vanilla soda or ginger ale (basically, sliced ginger, water, sugar, plus some ground ginger for extra oomph), then you will be fine - just remember to get the best ingredients.
Enjoy your soda experience!