Cartridge and Crossflow Filtration: Cleaning with Enzymes
Last updated: 6/2021
Applies to: Fruit-based beverage producers using crossflow filters or cartridge filters. This guide details the importance of cleaning with enzymes for general maintenance and troubleshooting difficult filtrations.
PECTIN AND MEMBRANE FILTERS
All wine and fruit-based beverages have protein, pectin, and pectin-related structures that can present issues in the filtration process. During filtration, these structures collect in filter media. This is especially problematic in membrane filter systems as membranes are not replaced with the frequency of other filtration medias and are instead cleaned and re-used extensively.
This problem may present in an obvious fashion, causing a nightmare filtration day; or it may present over time as these structures slowly accumulate on the membrane matrix. Even if the filter is diligently cleaned after each use, some of these compounds can’t be removed by standard chemical cleaners. Sanitization can make even things worse, as hot water can bake these compounds into the membrane matrix such that no future cleaning efforts can remove them.
THE ROLE OF ENZYMES
To combat both these immediate and long-term effects, we’ve developed a two-pronged strategy to maintain membrane efficiency and minimize wine loss.
- The first step involves finishing wine with broad-spectrum enzymes to help break down these structures prior to filtration (SCOTTZYME® KS or SCOTTZYME® SPECTRUM).
- The second step involves regular membrane cleanings with SCOTTZYME SPECTRUM. As membranes see multiple wines in a day, week, and bottling season, there are a wide range of structures that need to be removed. SPECTRUM is a proprietary, high-concentration, broad-spectrum enzyme that can target a large portion of these structures in one treatment.
*Please note: SPECTRUM does not contain glucanase. If you suspect glucans are present, consider using LALLZYME MMX in the wine at least 2 months prior to membrane filtration. Glucans are often present because of mold pressure, but go unnoticed until causing issues during filtration. Obvious Botrytis is the commonly promoted warning sign for glucan presence; However, even slight mold pressure or frost taint (split berries, increased mold pressure), can lead to glucan-related filtration issues.
Enzyme Cleaning Protocol
When can I clean my membranes with SCOTTZYME® SPECTRUM?
Following filtration: Following a difficult filtration, rinse your membranes in cool water but do not yet clean with caustic or do a hot sanitization. Proceed with the enzyme protocol.
During filtration: Should you need to clean your membranes during filtration due to premature pressure building, simply empty the filter and rinse with cool water before continuing with the enzyme protocol.
Why shouldn't I do a sanitation before this protocol?
When you heat up membranes by way of steam or hot water (>160°F), protein and other colloidal material gets baked into the membrane matrix such that the enzyme cannot remove them. Thus, you want to do this protocol before a steam or hot water treatment.
- Ensure you have first rinsed your membranes with cool water only.
- Start by preparing water at 105 - 120 °F. Do not exceed 130°F as the enzyme will be less effective. Prepare enough water to cycle through your filter.
- Acidify the solution to pH 4.0-4.5. Typically, a 0.2%-0.3% by weight addition of citric acid should suffice, depending on your starting pH.
- Add SCOTTZYME® SPECTRUM to this solution at the dosage of 0.75 – 1 mL/L.
- Run the solution through the system in a closed loop in either rinsing or cleaning mode. The speed will increase as the build-up is released. Watch the temperature as this procedure can increase it.
- At 125 degrees, shut the system off and allow it to sit for 30 minutes.
- Rinse and continue filtration or complete a sanitization as needed.
- Complete steps 1-4 of the crossflow protocol above.
- Run the enzyme solution through the pre-filter and membrane housing with the cartridges intact. Watch for the differential pressure to decrease.
- Once full, let the system sit for 30 minutes.
- Complete a forward flush with tepid water, drain, and continue filtration or complete a sanitization as needed.
*ENSURE you do not exceed the maximum differential pressure as indicated by your cartridge manufacturer, especially at the higher temperatures of this protocol.
Download a printable copy of this protocol by clicking below.Download