pasteurization & shelf stability

Hey guys,

New to the forum. I've been reading posts for the last couple weeks trying to get myself up speed on soda carbonating and bottling.

I have a couple shrubs I've made that I mix with sparkling water from a soda stream unit, and I'd like to do a small run for resale at some stores in my area.

I'm trying to keep things as clean tasting as possible, so I'm doing the extractions using a cold process (either with sugar or vinegar, depending on the fruit/herb/aromatic). This is causing the yeasts in the vinegar to kick into gear and I get the development of a mother of vinegar in the process, and obviously a change in flavour profile as time passes.

I'd like to bottle with a decent shelf life at room temp, so that the product is shelf stable (like any other soda).

My general plans and understanding would be as follows (I'd love to hear any differing opinions or thoughts)

1. I'm going to need to pasteurize my syrup/shrub. I didn't want to do this, but I don't see any way around it if I want shelf stability.

2. I'm going to then bottle with carbonated water and add the right amount of syrup, and cap the bottle. Given the PH of the shrub, my hope is I don't need a natural preservative like citric acid - it should already be fairly acidic (it's tart to drink).

Is there a need to pasteurize the water before carbonating it, or would commercial producers just use filtered water?

Am I better low and slow on the pasteurization process, or hot and fast? The reason I've been using a cold extraction is to preserve the freshness of the ingredients, so my goal is to stay away from the cooked fruit flavour notes that come with heat.

Can I get away with no preservative? I'd like decent flavour retention for 6-12 months and safe consumption indefinitely.

Happy New Year to all.

A

I don't think commercial sodas have a 12 month shelf life.
Also I believe there is a flash pasturization process which some bottling plants use (some low cal soda uses it when I read up on it).

I would also look at shelf preservatives. Citric, ascorbic, and phosphoric acids. As well as probably sterilizing (not sanitizing ) the bottles before hand (you can bake them to do this. I do 400 for 2 hours. Start in a cold over and let cool on the counter ).
Hope this helps.

One of the key elements to pasteurization is heating it while sealed and then not exposing it to air. So pasteurizing your syrup and water separately and then bottling will do nothing for you unless you're able to bottle in an aseptic environment (unlikely).

If you absolutely don't want to have any preservatives, you'll want to pasteurize after bottling. Also, if this is something that you want to sell to the public, you'll want to verify your process and keep detailed batch records. Get a dishwasher thermometer that will record a max temp that you can stick in a dummy bottle with every batch you pasteurize to be sure that it reaches the correct temperature. I believe you'll want to hit 190°F

Your question about hot and fast versus low and slow is a difficult one to answer. It has to do with the fact that the effectiveness of pasteurization is logarithmic, so without knowing other factors, it's hard to compare one method to the other or give specifics about what time/temperature combination is the best for you. Hitting 190° is a ballpark figure, but should probably be effective for what you want to do and would fit with your capability for validation (max temp dishwasher thermometer, which won't really tell you how long it's been at that temp, just that it hit it).

And if you're looking for "natural preservatives" any acids will only work to a certain point. The environment inside your beverage is already very acidic and yet you're still fermenting a bit, so any effective amount of acidification will be so intense that you mess up the flavor. The preservative function of acids is a different mechanism than those such as sodium benzoate and potassium sorbate, and are much less effective in comparison. On their own they will not entirely prevent the microbial growth that would be the "spoilage organisms" in this case.