Sunday, 7 December 2008

Sugar 1920 - 1939 (part two)

More on sugar, courtesy of "Brewing Science & Practice" H. Lloyd Hind, published in 1943. It's a wonderful source on many aspects of brewing, but especially on materials. I'm sure I'm going to have to do some editing of my brewing materials section of the 1920-1939 chapter. Way too long, I fear. But at least writing it has helped my education.

Today it's the turn of the less fashionable and not so easily defined sugars. And caramel. A laugh a minute, it is. If you find hydrolosis amusing.

Starch sugars
These were made by the hydrolytic action of acids, such as dilute sulphuric or hydrochloric acid, on starch. The source of the starch was usually maize, but sometimes sago, tapioca or potato were used. The starch was first converted to maltose and then to glucose. (Source: "Brewing Science & Practice" H. Lloyd Hind, 1943, page 303.) If the conversion process was stopped as soon as all the starch had disappeared it produced a sugar called dextrin-maltose which only fermented partially and slowly.

The flavour of glucose was much more neutral than cane or invert sugar. It was most useful in drier beers, particularly lagers.

It was sold either as glucose syrup or glucose crystals. The extract was between 73 and 78 brewer's pounds per 224 pounds, depending on the water content.

Corn syrup, glucose syrup and dextrin-maltose were were types of starch sugars where hydrolosis was incomplete. Consequently, they contained varying proportions of maltose and dextrin. As they were less easily fermentable than other sugars, they were particularly suitable for primings that were intended to condition beer in the cask slowly.

Mixed sugars
Various combinations of cane sugar, glucose, invert sugar and corn syrup were sold as proprietary brands, sometimes with caramel added for colour. They were designed to have specific flavour characteristics and fermentability, depending on their intended use. Often they were used as sources of partially fermentable extract. They could be added either in the copper or as primings.

The colour varied from pale to extremely dark, according the degree of carmelisation. Extract wwas between 65 and 75 brewer's pounds per 224 pounds.

At the front and back of The Brewers' Almanack there were several pages of advertisements for these types of proprietary sugars. You can see one such to your left. Dopey git that I am, I've only just noticed that it's for Hay, one of the names that turns up in brewing logs. Whose was it, Whitbread or Barclay Perkins? Whitbread, I think.

Caramel is made by heating sugar to around 220º C. Three slightly different compounds, with different degrees of solubility are present in caramel: caramelan, caramelen and caramelin. Either glucose or cane sugar were used to produce caramel. Depending on how the caramel was made it had varying degrees of colour and fermentability. In general, the darker the colour, the lower the fermentability.

The main use of caramel was for colouring, though it was also important for adding flavour. Caramel was often added to make colour adjustments to even pale beers to get the colour range specified for a beer. Barclay Perkins sometimes added caramel to all their beers for this purpose. They also used caramel to produce dark versions of their Milds, which were a deep amber colour as brewed. At the front of some of their brewing logs it's specified how much caramel needs to be added to raise the colour of a certain volume of beer by 1º Lovibond.

The colour of caramel was based on a 0.1% solution measured in a 1 inch cell and given in degrees Lovibond. "Caramel should not produce a precipitate in the course of 24 hours in bright beer coloured to resemble stout, neither should there be any loss of colour under these conditions in a week. Wort coloured in the same manner should show no loss during fermentation."

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