UV versus Ozone sterilization/best practices/QC instead of Tunnel Past.

[eoconnor101]

First off sorry if this is in the wrong section, didn't really know to put it in QC or here. We are going to be doing some packaging for a distillery that back blends sugar (or juice) back into the finished product, since we won't be fermenting anything we won't be sterilizing by boiling. The idea is to just pass filtered water through an exchanger against glycol and then mix. We have looked at tunnel pasteurizers and for now the footprint/cost is probably going to prevent it. I was going to possibly install a UV sterilizer inline with the water in supply, as well as tee off that same system to the can rinser pre fill, and then plate and run PCR on pre and post package. Obviously this won't be the same QC guarantee as a tunnel, but I'm hoping we can do enough that everyone rests easy. Should I be considering Ozone in addition or instead of UV? Does anyone have any suggestions about what company to contact regarding either UV or Ozone sterilization of water? My hope was to avoid RO water as well as using HLT water through an exchanger as it would interfere with brewing operations too much. Any advice is greatly appreciated. Our hope is if their business grows we would be able to add a tunnel down the line but they look like space/water/energy hogs.

[gitchegumee]

If water is all that you are trying to sanitize, then that is relatively easy. UV is usual, but if it is a critical process, then you should have a way to ensure it's working. At the least you would want an indicator or interlock with the lamp to assure that it's working. I've seen UV units with green light showing all ok only to see the lamp is burnt. I'd use belt & suspenders and use ultrafiltration as well. More worrisome to me is the packaged product. Even if the water is sterile and the spirit to which it's blended is sterile, if it is back sweetened into low alcohol/low acid product, then I'd be concerned about post-packaged product. Best way to ensure a shelf-stable product is with tunnel pasteurizer. Lacking the major utility, space, and cost considerations, then batch pasteurization in a small tub of some kind may work. I've seen it done many ways, including using an old hot tub.

[dick murton]

A couple of thoughts, but not in the same order as the questions asked.
Re RO water – this is likely to depend on the mineral quality of your water. If it is high in mineral salts, then it might affect the flavour or quality of the blended product. I suggest you do trials using your own water as proposed, and compare to some liquid blended with RO water. As you are blending for someone else, it is essential you get their approval for whichever water you use. For what it is worth, I would use RO treated water. Depending on you production volumes, you may not need a large RO plant, but may need a holding tank large enough for at least one complete batch. Again, if you do opt for RO, I would carry out trials ideally with a rented RO system you propose to use, and get the suppliers approval for the quality of the product before finally purchasing said system.

If you are blending anything slightly coloured or turbid such as fruit juice, then UV is simply not going to work – the transmission will be too low, and the risk of fouling so further reducing the transmission increased.

Which leaves you with chemical sterilisation, filtration or pasteurisation.
If you are required to ensure that the final blended product is sterile, then simply sterilising the water by any method is not adequate as you don’t know the quality of the other blending materials.

If you may have fruit juice or anything similar with particulates in it, then sterile filtration is not going to work. You could investigate chemicals used by the fruit juice packaging industry, to treat the final blended product, assuming this is allowed where you are based.

Which leaves you with pasteurisation. You have a choice then – flash pasteurisation and sterile filling, or post filling tunnel pasteurisation. As you will be adding sugar and or juice, then there is a fairly high microbiological risk (obviously to some extent at least dependent on the alcohol content of the final product). So my preference is for tunnel pasteurisation unless your filler hygiene is exemplary. To improve filler system hygiene consider hypochlorous acid rinses and or UV lamps on the filler and associated conveyors.

[eoconnor101]

Thanks guys. We already have an RO unit but it is piped to the HLT/CLT and we probably cannot handle the additional load, my thought was to buy an additional unit, but the idea is that since this is for contract, some will want RO, some a blend, so not 100% there, a UV lamp to treat the water regardless seems like a no brainer. The issue with a tunnel or batch is that we don't really have the cash or BTU capacity in our boiler right now, and batch won't work for 100 cpm filler we just ordered. As for QC we will be running PCR and plating as well, we have not yet picked up anything nasty from our current filler in our beer or the backsweetened tea we produce. I will highly suggest ppl are open to citric acid pH adjustment to 3.5 and ABV above 5%, and sorbate addition at least (benzoate probably better but the name scares people, sorbate sounds like dessert). I added sorbate to a smoothie sour I did 3 months ago and the cans have yet to puff up at room temp. Flash pasteurization would be done between 2 tanks right? The idea here is just mixing tank, no transfers, no filtration.....plus I don't think our boiler can handle it yet. I need to look into rotary pasteurization as I just heard about it and it may be an option?

[brewbot]

Interesting...I can't comment on which method is ideal for your situation. But I can comment on a Flash Pasteurizer since I've used this in a few different breweries. You don't necessarily NEED steam as long as it is designed accordingly, and use of hot water from the HLT just needs to supply the design temp and flow rate. If using steam, you can use low pressure (10psi at unit after pressure drops) again as long as its spec'd out that way. Also have a target in mind, x PU units which is the number of seconds spent above 165F (if memory serves) or is it 65C? Cooling back down should also be straightforward to use cold water from CLT or glycol from your header as long as it's designed that way. Rolec designed a custom solution for a brewery I worked in...using a single tank inline to the filler. There are many ways to achieve this however. Talk to suppliers, they are often helpful and the better ones have legit engineering groups/depts that will guide you through your application. Automation is expensive but helps in getting closer to repeatability. Manual-operated can work well as long as the operator has the attention to detail needed to dial it in. I wish somebody out there made a micro tunnel unit!!