Thursday, 1 September 2016
Was Scottish Ale fermented like Lager?
I’m sure this misapprehension is partly based on just looking at pitching temperatures rather than the actual fermentation temperature. Because they didn’t pitch at a certain temperature and hold the wort at that for the whole duration of the process. Brewers both sides of the border did something more complex.
Usually the temperature rose quickly in the first day or two, then, through use of attemperators, was held at a certain point for a while, then dropped down again to around or just below the pitching temperature. The maximum fermentation temperature was usually at least 10º F higher than the pitching temperature.
Another factor helping deceive about fermentation temperatures is the strength of many Scottish beers in the 19th century. The stronger the beer, the lower the pitching temperature, as more heat will be generated during the fermentation. Many Scottish beers were pitched at 54º - 55º F because they had OGs over 1100º.
I just realised that I had a wonderful example of how Scottish Ales weren’t fermented like Lager. Because I’ve got examples of both right next to each other in one William Younger brewing record from 1880:
This shows the fermentation record of three beers, XP, PX and XP. XP being a Pale Ale and PX a Pils. The top two rows are for one XP brew, the last two for another XP with the PX in the middle row.
The XPs were pitched at 59º F and 58.5 º F, when the gravity was 1053º. The PX was pitch at 54º F, gravity 1058º. The columns that follow are a temperature followed by the gravity. The temperature of the two XPs rises to a maximum of 70 º F and 68º F before falling again.
The process for PX is very different. The temperature falls immediately to 45º F, then to 41º F. It stays at 41-42º F for the next couple of weeks as the fermentation slowly progresses. All three beers were brewed on 11th April 1880. The two brews of XP were both racked of the 18th April, a fermentation of 8 days. The PX wasn’t racked until 3rd My, a total of 23 days.
Even though the XP and PX were pitched at quite similar temperatures, the process of the fermentation was totally different. The Pils was fermented much, much cooler and more slowly that the XP.
The answer to the question in the title: no. Not even vaguely