American pale ale brewing

 First trial

Malt grain 500g

Boil water, 4 Litres 

Grains in cloth bag

Boiling around 100 deg c

Wort boiling

Cold water bath

Using metal filter ( is it really necessary to filter at all?)

Carboy

水封 排氣閥 One way valve 

Malting enzymes:

Beta Amylase and Alpha amylase has major role  for maltose conversion.

Why 68 °c?

Beta-amylase has an optimal range pH 5.2 to 5.6

Reference 

Control mash temperature 

4L of water used

3L of wort made

2L(2.5L?) to carboy 

pH value changes from Hanna instruments 

From john palmer:

Beerandbrewing water and wort pH:

You might recall from high school chemistry class that pure distilled water has a pH of 7.0, but most municipal water sources have a higher (slightly alkaline) pH above 7.0, due to minerals they pick up from ground and surface sources.

Grains, in contrast, are acidic, meaning they will lower the pH of the water/grain mixture. Dark roast malts are very acidic and will have the largest effect, while pale malts are only slightly acidic.

So when we mix our slightly alkaline water with our acidic grains, we get a pH that is often in the range of 5.0–7.0. That will depend on how alkaline the water was to start with, how much acid the water itself can absorb (which is measured by the water’s residual alkalinity), and how much dark vs. light malt we use.

Since we want to get the mash pH down to 5.2–5.6, we often need to use additional acid to drive it down further. 

When to measure pH?

10 minutes after starting to boil at 67 deg C, ie saccharification rest.

Hops are added for bitterness and aroma, and utilization of the bittering substances [α-acids] takes place at the elevated temperature of the boil.  Heat and wort pH will affect the isomerization of the α-acids to iso- α-acids with a slight advantage of higher utilization at higher wort pH [5.8]

Checking the pH of yeast before repitching it into the wort is recommended.  A tired yeast slurry will have a higher than normal pH [>4.5] due to cytoplasm released by autolysed yeast.  Healthy yeast will respond positively to clean, cold, oxygenated wort with adequate nutrients and no competition. 

5.2 pH stabilizer:

The 5.2 stabilizer is a blend of two salts. They are neutralized versions of phosphoric acid. They are monosodium phosphate (Na H2 PO4) and disodium phosphate (Na2HPO4). TBC. As this type of buffet can only be at pH 5.8 to 7.4  from electricbrewery

Datasheet 

Include

E513 sulphuric acid

E507 hydrochloric acid

35ml of AMS per hL (100L)of water reduces the alkalinity by 64 mg/litre (ppm) and increases chloride levels by 22.5 mg/litre (ppm) and sulphate levels by 31 mg/litre (ppm).

Brewersfriend watercalc said AMS/CRS  is 6.3% HCL and 8.6% H2S04