Place all ingredients together in a large bowl and mix very well. You can add ice and drink the switchel immediately at this point if you like.

Optional step: If you prefer a more carbonated beverage, then take this additional step: slowly pour mixture into large glass bottles with wire and ball stoppers (I like these) and fasten the lids. Alternatively, you can mix up the switchel with cold, sparkling mineral water (I prefer this brand) and get the bubbly right away without bottling.

If you are fermenting in bottles instead of drinking immediately, leave the sealed bottles on the counter for at least 2-3 days (up to a week or two is fine also if your kitchen is very cool) to add carbonation and then refrigerate. Open in the sink slowly and only when the beverage is very cold to prevent explosions or the switchel foaming out of the bottle and making a mess.

If you used fresh ginger, sieve the switchel as you pour it from the bottle into your glass.

Sip and enjoy either alone or with ice. Refrigerate unused portions in glass containers only.