Bottle Priming with Dextrose Syrup
The easier, cleaner, accurate way of priming beer bottles.
You will need:
· Syringe(s) of appropriate size for your bottles (5, 10 and/or 20 ml)
· Pyrex or similar microwaveable measuring jug
· Dextrose powder, typically around 200 grams per 25-litre batch
· Scales accurate to the nearest 5 grams at most
Open the included Excel spreadsheet and follow the web link at the top. Select the style of beer you are bottling or enter the desired CO2 volume (2.1 is common for stouts; 2.4 works for most other styles). Enter the temperature and volume of beer; these are in imperial units, so there is a converter near the top of the Excel spreadsheet to help out. The online calculator will give you a weight of dextrose, in grams.
Take the figure obtained in Step 1 and enter it into the orange box in the Excel sheet. Enter the size of your batch into the green box. Write down the following output figures from the calculator:
1. Total incl. buffer (g):
2. Add water to total volume (mL):
3. Liquid per Bottle (mL): Record the figure for each bottle size that you’re using.
Place your measuring jug on the scales and zero them. Add dextrose equal to Figure #1 from Step 2 (this will be more than what the online calculator said). Add boiling water to the dextrose until the jug reads the volume produced by Figure #2 from Step 2. This may require some stirring until the dextrose is mostly dissolved and the final liquid level reached.
Place the jug in the microwave and heat until boiling and all dextrose is dissolved. Leave in the microwave to cool until you’re ready to use it.
Clean and sterilise your syringes along with all your other bottles and gear. Into each bottle, syringe the amount of syrup indicated by Figure #3 from Step 2. Your bottles are now primed correctly for your particular beer style and temperature! Hint: try to match the syringe size to the bottle size if possible (for example, it’s hard to measure 3.8 ml accurately on a 20 ml syringe).
Note: you should have about 25% of the original dextrose syrup remaining. The Excel calculator builds in a 25% buffer so you don’t have to syringe up every last drop, only to realise that you still don’t have enough. It’s much easier this way and you don’t end up wasting much.
The syrup method can also be used with Dry Malt Extract instead of dextrose, but getting the DME to dissolve in boiling water is a challenge!