Overview
Yeast harvested from primary fermentation is available for new fermentations. This SOP covers aseptic yeast handling, yeast brink preparation, and required documentation. Half-BBL kegs modified with a 4 inch diameter TC fitting are used to store yeast, on water with tetra-hydro-isohumulone, for periods of time up to 7-14 days. Water is responsible for slowing down declining viability and vitality. Tetra-hydro-isohumulone is responsible for anti-bacterial action during storage, and is potentiated during acid washing just prior to pitching. Acid washing is carried out with 25% food grade phosphoric acid prior to fermentation, to adjust the brink to a pH around 2.5, with a minimum contact time of one hour but not more than two hours. Our yeast brinks have fins protruding internally to help with agitation when mixing to take samples for counting, and during acid washing. Filled yeast brinks are capped with a 4” TC cap with a ¾” TC port for a ¾” TC diaphragm valve and an airlock. The valve can be closed during mixing, but is left open during storage to avoid a buildup of pressure in the brinks. An airlock is fitted into the ¾ TC diaphragm valve to keep the brinks protected from particulate being able to make its way in.
MATERIALS AND APPARATUS
1. Your own 5 gal bucket ½-¾ full with sanitizer/water ( I use red for sanitizer)
2. Cleaned empty sanitized yeast brinks ( 180F water from HL tank)
3. For each brink the following cleaned parts
-One 4” TC cap with ¾” TC port.
-Two ¾” TC gaskets
-One 4” TC gasket
-One ¾” TC diaphragm valve
-One 4” TC clamp
-One ¾” TC clamp
-One airlock modified to fit into the ¾” TC diaphragm valve
4. Your own bucket (I use green colored) for heat sanitizing parts
5. A hose with 1-1/2” TC fitting, a gasket, and a clamp
6. A 1-1/2” to 2” TC reducer if your PFV has a 2” valve
7. Patco(non-silicone) anti-foam
8. Tetra-hydro-iso-humulone and 32mL measuring cup(graduated cylinder marked at 32ml)
9. Your own sanitizer spray bottle
10. A bucket for excess yeast drippings and removing the cake slug in the outlet
11. Optional: A flashlight and bucket to sit on
Procedure
Step 1:
Take your clean brink parts and pre-assemble them. Inspect each part, gasket, clamp for residue and debris at this time.
Take your 4” TC cap with the ¾” TC port and hold the 4” TC gasket in place with the 4” TC clamp
Take your ¾” TC gasket and put it in the ¾” TC port on the 4” cap
Put the ¾” TC diaphragm valve on the ¾” TC port with the gasket and clamp it on with the ¾” TC clamp
Repeat this for each empty brink you need to fill
Now you have a pre-assembled brink top ready to be used
Step 2:
go over to the hot water supply on the wall, brink your red(sanitizer) and green(hot sanitize) bucket, put your reducer in the red(sanitizer) bucket if you need it for later. Put the brewery hose sprayer in the red(sanitizer) bucket to keep it clean, Have your anti-foam and tetra-hydro close by and ready
Step 3:
Attach your 1-1/2” TC hose to the hot water supply on the wall, make sure the HLT is 170+F and that caustic or sanitizer is not running thru the wall supply.
Take your pre-assembled brink top(s) and fit them nicely into your green bucket(you may need two buckets etc..)
Fill the bucket covering the brink tops with water 170F or hotter. Leave them soaking in the hot water until step 4
Fill the empty brinks to the brim with 170F or hotter water.
Step 4:
Let the brink tops and brinks soak in the scalding hot water for at least 5 minutes. Usually by the time you finish filling the last brink the first one is ready to be emptied(step 5)
Take your green bucket at this time and empty it put the caps into the red(sanitizer) bucket(s)
Step 5:
Take one brink at a time and tip it over and empty out all of the scalding hot water.
Be extra careful of introducing any contamination back into the brink at this point, the floor is dirty so find an appropriate place with plenty of space to work with.
and take the brewery hose out of the red(sanitizer) bucket and fill the brink up with 15-20 seconds of water at full pressure, or about half way up the bottom most mixing fin
<pic>
Step 6:
immediately after step 4 take your tetra-hydro-isohumulone and put 32mL into the brink and put 1fl.oz of anti-foam(~30mL)
Step 7:
Take a pre-assembled cap out of the red(sanitizer) bucket and fix it to the top of the brink, Since you had the 4” gasket held captive with the 4” clamp you can do this in one swift movement.
Step 8:
make sure the diaphragm valve is open and spray the outside of the brink with the hose to cool it down, after it’s cooled make sure to close the diaphragm valve again.
Put the hose back into the red(sanitizer) bucket if you have more brinks to prepare
go back to step 5 and repeat for each additional brink
Step 9:
Take your prepared brinks and sanitizer bucket over to the PFV you will be harvesting from.
Remove the hose from the wall and put it into your red(sanitizer) bucket
Pull the blue airlock bucket out and check the PFV’s temperature
Grab the fermentor tracking sheet for your PFV and note the time and temperature before you harvest in the crash data section, grabbing the documentation first will help mitigate mistakes happening.
Step 10:
Take the cap off the bottom outlet of the PFV, spray everything liberally with sanitizer.
With a clean yellow bucket open the valve and expel the slug BEFORE attaching the hose for harvesting(it will just get clogged immediately)
If you are working on a 2” tank fix the reducer to the valve and then fix the hose to the tank. Empty and clean the yellow bucket out and then put the end of the hose into the yellow bucket.
Step 11:
Take your sanitizer spray and spray around the top of the brink and then remove the cap, place the cap into your red(sanitizer) bucket.
Spray the end of the harvesting hose liberally with sanitizer and then slowly fill the brink, it should take about 3-5 minutes to fill it if you’re going at an appropriate speed.
Harvesting too fast will splash yeast everywhere, and you run the risk of cavitation in the yeast cone which siphons beer into the slurry.
Fill the brinks past the 40L mark as the slurry is foamy and will settle.
Half way up the top most mixing fin is a good average area to shoot for. Once the brink gets mixed and settles out the slurry will settle out to about 40L once it de-foams itself.
Step 12:
liberally spray the opening on the brink with sanitizer and then remove the cap assembly from the red bucket and fix it to the brink. Make sure again at this time that the diaphragm valve is closed.
Repeat step 11 and 12 for each additional brink
Step 13:
once all the brinks are filled or the yeast slurry has gotten thin mark the total harvest amount on the fermentor track sheet in the crash data area.
Grab a yeast brink tag and fill it out completely for each brink that was harvested noting the Date harvested, Beer harvested from + batch #, PFV#, generation, amount of tetra and anti foam, and the brink #.
Step 14:
once the paperwork is taken care of mix each brink and then move them into the cellar cooler. Open the diaphragm valves on each brink slowly, spray liberally with sanitizer to remove any yeast residue that ejects.
Soak the airlocks in sanitizer then affix the airlocks into the diaphragm valve(s) and fill them with sanitizer.
Step 15:
make sure to remove the hose from the fermentor and then clean all extra parts and put them away, check the racking arm for yeast, and clear it out using the yellow bucket, re-cap the fermentor outlets, spray down any yeast mess, clean out the yellow bucket and put it away, remove the airlock tube and put a cap on the gas arm.
Additional Information about harvesting
Adding a small amount of water to the brinks before harvesting is done to help evenly disperse the tetra-hydro and anti-foam while filling. More importantly it dilutes any beer left in the yeast slurry and slows down metabolism. Even at 38F in the cellar during storage the yeast are active, albeit very slowly. The added water slows down the yeast using up their energy storage and extends the time that harvested brinks can be stored and remain vital enough for use in a new fermentation.
Adding a small amount of tetra-iso extract to the brinks is used to combat beer spoiling microorganisms
tetra-hydro-isohumulone in 20Kg at 10% strength.
10% strength is 100,000 parts per million
we uses 80PPM tetra-hydro to inhibit beer spoiling bacteria.
40L = 40,000mL
32mL @ 100,000PPM is diluted into 40,000mL of yeast slurry which gives us 80PPM tetra-iso in the brink
at 80PPM tetra exhibits antibacterial properties. It acts as an ionophore inhibitor in bacteria. That is, it prevents bacteria from moving ions through their cell walls resulting in their death.
Acid wash brinks before pitching to a pH of about 2.5(see acid washing SOP). At this low pH the anti-bacterial activity of the 80PPM tetra is greatly increased and kills up to 99.99999%(yes 5 9’s after the decimal) of the bacteria in the brink.
Storage with an airlock is not only to prevent pressure in the brink from building up to dangerous levels. Pressure in the brink is also stressful to the yeast. The airlock allows the brinks to remain aseptic but also at atmospheric pressure as to not harm the yeast during storage.
Yeast harvested from primary fermentation is available for new fermentations. This SOP covers aseptic yeast handling, yeast brink preparation, and required documentation. Half-BBL kegs modified with a 4 inch diameter TC fitting are used to store yeast, on water with tetra-hydro-isohumulone, for periods of time up to 7-14 days. Water is responsible for slowing down declining viability and vitality. Tetra-hydro-isohumulone is responsible for anti-bacterial action during storage, and is potentiated during acid washing just prior to pitching. Acid washing is carried out with 25% food grade phosphoric acid prior to fermentation, to adjust the brink to a pH around 2.5, with a minimum contact time of one hour but not more than two hours. Our yeast brinks have fins protruding internally to help with agitation when mixing to take samples for counting, and during acid washing. Filled yeast brinks are capped with a 4” TC cap with a ¾” TC port for a ¾” TC diaphragm valve and an airlock. The valve can be closed during mixing, but is left open during storage to avoid a buildup of pressure in the brinks. An airlock is fitted into the ¾ TC diaphragm valve to keep the brinks protected from particulate being able to make its way in.
MATERIALS AND APPARATUS
1. Your own 5 gal bucket ½-¾ full with sanitizer/water ( I use red for sanitizer)
2. Cleaned empty sanitized yeast brinks ( 180F water from HL tank)
3. For each brink the following cleaned parts
-One 4” TC cap with ¾” TC port.
-Two ¾” TC gaskets
-One 4” TC gasket
-One ¾” TC diaphragm valve
-One 4” TC clamp
-One ¾” TC clamp
-One airlock modified to fit into the ¾” TC diaphragm valve
4. Your own bucket (I use green colored) for heat sanitizing parts
5. A hose with 1-1/2” TC fitting, a gasket, and a clamp
6. A 1-1/2” to 2” TC reducer if your PFV has a 2” valve
7. Patco(non-silicone) anti-foam
8. Tetra-hydro-iso-humulone and 32mL measuring cup(graduated cylinder marked at 32ml)
9. Your own sanitizer spray bottle
10. A bucket for excess yeast drippings and removing the cake slug in the outlet
11. Optional: A flashlight and bucket to sit on
Procedure
Step 1:
Take your clean brink parts and pre-assemble them. Inspect each part, gasket, clamp for residue and debris at this time.
Take your 4” TC cap with the ¾” TC port and hold the 4” TC gasket in place with the 4” TC clamp
Take your ¾” TC gasket and put it in the ¾” TC port on the 4” cap
Put the ¾” TC diaphragm valve on the ¾” TC port with the gasket and clamp it on with the ¾” TC clamp
Repeat this for each empty brink you need to fill
Now you have a pre-assembled brink top ready to be used
Step 2:
go over to the hot water supply on the wall, brink your red(sanitizer) and green(hot sanitize) bucket, put your reducer in the red(sanitizer) bucket if you need it for later. Put the brewery hose sprayer in the red(sanitizer) bucket to keep it clean, Have your anti-foam and tetra-hydro close by and ready
Step 3:
Attach your 1-1/2” TC hose to the hot water supply on the wall, make sure the HLT is 170+F and that caustic or sanitizer is not running thru the wall supply.
Take your pre-assembled brink top(s) and fit them nicely into your green bucket(you may need two buckets etc..)
Fill the bucket covering the brink tops with water 170F or hotter. Leave them soaking in the hot water until step 4
Fill the empty brinks to the brim with 170F or hotter water.
Step 4:
Let the brink tops and brinks soak in the scalding hot water for at least 5 minutes. Usually by the time you finish filling the last brink the first one is ready to be emptied(step 5)
Take your green bucket at this time and empty it put the caps into the red(sanitizer) bucket(s)
Step 5:
Take one brink at a time and tip it over and empty out all of the scalding hot water.
Be extra careful of introducing any contamination back into the brink at this point, the floor is dirty so find an appropriate place with plenty of space to work with.
and take the brewery hose out of the red(sanitizer) bucket and fill the brink up with 15-20 seconds of water at full pressure, or about half way up the bottom most mixing fin
<pic>
Step 6:
immediately after step 4 take your tetra-hydro-isohumulone and put 32mL into the brink and put 1fl.oz of anti-foam(~30mL)
Step 7:
Take a pre-assembled cap out of the red(sanitizer) bucket and fix it to the top of the brink, Since you had the 4” gasket held captive with the 4” clamp you can do this in one swift movement.
Step 8:
make sure the diaphragm valve is open and spray the outside of the brink with the hose to cool it down, after it’s cooled make sure to close the diaphragm valve again.
Put the hose back into the red(sanitizer) bucket if you have more brinks to prepare
go back to step 5 and repeat for each additional brink
Step 9:
Take your prepared brinks and sanitizer bucket over to the PFV you will be harvesting from.
Remove the hose from the wall and put it into your red(sanitizer) bucket
Pull the blue airlock bucket out and check the PFV’s temperature
Grab the fermentor tracking sheet for your PFV and note the time and temperature before you harvest in the crash data section, grabbing the documentation first will help mitigate mistakes happening.
Step 10:
Take the cap off the bottom outlet of the PFV, spray everything liberally with sanitizer.
With a clean yellow bucket open the valve and expel the slug BEFORE attaching the hose for harvesting(it will just get clogged immediately)
If you are working on a 2” tank fix the reducer to the valve and then fix the hose to the tank. Empty and clean the yellow bucket out and then put the end of the hose into the yellow bucket.
Step 11:
Take your sanitizer spray and spray around the top of the brink and then remove the cap, place the cap into your red(sanitizer) bucket.
Spray the end of the harvesting hose liberally with sanitizer and then slowly fill the brink, it should take about 3-5 minutes to fill it if you’re going at an appropriate speed.
Harvesting too fast will splash yeast everywhere, and you run the risk of cavitation in the yeast cone which siphons beer into the slurry.
Fill the brinks past the 40L mark as the slurry is foamy and will settle.
Half way up the top most mixing fin is a good average area to shoot for. Once the brink gets mixed and settles out the slurry will settle out to about 40L once it de-foams itself.
Step 12:
liberally spray the opening on the brink with sanitizer and then remove the cap assembly from the red bucket and fix it to the brink. Make sure again at this time that the diaphragm valve is closed.
Repeat step 11 and 12 for each additional brink
Step 13:
once all the brinks are filled or the yeast slurry has gotten thin mark the total harvest amount on the fermentor track sheet in the crash data area.
Grab a yeast brink tag and fill it out completely for each brink that was harvested noting the Date harvested, Beer harvested from + batch #, PFV#, generation, amount of tetra and anti foam, and the brink #.
Step 14:
once the paperwork is taken care of mix each brink and then move them into the cellar cooler. Open the diaphragm valves on each brink slowly, spray liberally with sanitizer to remove any yeast residue that ejects.
Soak the airlocks in sanitizer then affix the airlocks into the diaphragm valve(s) and fill them with sanitizer.
Step 15:
make sure to remove the hose from the fermentor and then clean all extra parts and put them away, check the racking arm for yeast, and clear it out using the yellow bucket, re-cap the fermentor outlets, spray down any yeast mess, clean out the yellow bucket and put it away, remove the airlock tube and put a cap on the gas arm.
Additional Information about harvesting
Adding a small amount of water to the brinks before harvesting is done to help evenly disperse the tetra-hydro and anti-foam while filling. More importantly it dilutes any beer left in the yeast slurry and slows down metabolism. Even at 38F in the cellar during storage the yeast are active, albeit very slowly. The added water slows down the yeast using up their energy storage and extends the time that harvested brinks can be stored and remain vital enough for use in a new fermentation.
Adding a small amount of tetra-iso extract to the brinks is used to combat beer spoiling microorganisms
tetra-hydro-isohumulone in 20Kg at 10% strength.
10% strength is 100,000 parts per million
we uses 80PPM tetra-hydro to inhibit beer spoiling bacteria.
40L = 40,000mL
32mL @ 100,000PPM is diluted into 40,000mL of yeast slurry which gives us 80PPM tetra-iso in the brink
at 80PPM tetra exhibits antibacterial properties. It acts as an ionophore inhibitor in bacteria. That is, it prevents bacteria from moving ions through their cell walls resulting in their death.
Acid wash brinks before pitching to a pH of about 2.5(see acid washing SOP). At this low pH the anti-bacterial activity of the 80PPM tetra is greatly increased and kills up to 99.99999%(yes 5 9’s after the decimal) of the bacteria in the brink.
Storage with an airlock is not only to prevent pressure in the brink from building up to dangerous levels. Pressure in the brink is also stressful to the yeast. The airlock allows the brinks to remain aseptic but also at atmospheric pressure as to not harm the yeast during storage.
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