Abstract
Does continuing alpha amylase actity after the mash has been converted increase the wort fermentability? The literature suggests that alpha amylase has only little affinity towards shorter chained dextrines which should result in only a small affect on the fermentability of the produced wort. This experiment tries to answer this question.
Equipment
- 1/2 Gal beverage cooler as mash tun
- Weyermann Pilsner malt (0.5 kg)
- thermometer
- ladle
- pot for boiling the mash
- strainer and paper towles for latuering the mash
- bottles for fermenting the samples
- lager yeast (Wyeast 2206 from a home brew batch)
- sanitized syringe for measuring the yeast
- oxygenation stone and oxygen bottle
Procedure
- Mash in the pilsner malt to reach 70 *C
- adjust mash pH to about 5.3 if necessary
- once the mash is converted pull al cup of well mixed mash and lauter through a strainer and paper towel into a pot
- mix the grains with another cup of 70 - 80 *C water and lauter again
- the wort is brought to a boil for 15 min. This results in sanitiziation of the wort and stopping of any enymatic activity.
- fill the hot wort into a bottle that has been kept in boiling water. This will prevent cracking of the bottle.
- the hot bottle is capped with tin foil and placed outside where it will cool off faster
- This is repeated every 20 - 30 min for 5 samples
- Once all samples have been cooled to room temperature a sample is taken from each bottle to measure the starting extract.
- Then they are oxygenated for 10 s each and pitched with 5 ml yeast slurry. The yeast slurry is resuspended everytime a sample is taken to ensure that all wort samples get the same amount of yeast
- fermentation will happen at room temperature with repeated resuspension of the yeast via shaking
- Once all fermentation activity has stopped the apparent extract is measured and the limit of attenuation for each sample is calculated
