Beer colour affected by water chemistry and/or yeast?

[Martin Bridges]

I've just re-brewed a best bitter that I brewed a couple of months ago. The malt bill was virtually identical (just the addition of 100g of home-toasted Victory this time). However, the yeast is different this time (Wyeast 1275 Thames Valley as opposed to 1469 West Yorkshire) and I tweaked my water chemistry .

The beer this time is much paler. Last time was a chestnut sort of colour, this time it's a mid-amber. Could either the yeast or the water chemistry have had such a big impact on the colour?

[James P]

Did you compare your home-toasted to the commercial variety for colour?

[Martin Bridges]

There was none in the first recipe - it was a pure addition to the second recipe.

[James P]

That's weird, as long as the base malts had not changed (between batches etc)? That is their colour has minor changes between batches.

[Mike Neilson]

What did you add to the water?

[Reviled]

You did add a heap of salts and minerals, surely that has to affect the colour some how? I wouldnt suspect that its the yeast...

[Soren]

I think water chemistry can affect the color, but what the mechanism is I am not sure.

I would think mash temperature and especially sparge temp could have an impact as well, I would assume higher temps would extract more color.

Aerating above 20C can make the wort darker as well.

But to make such a dramatic difference sounds weird!

[MrC]

Was the boil less vigorous this time? Could be less kettle caramelisation.

[denimglen]

Both will change colour.

I believe it's the level of calcium, more calcium = less melanoidin colouring reactions.

Yeast will also affect it as well, like a less flocculant yeast will appear slightly paler because of the pale coloured cells in suspension, IIRC they may also affect colour in some other more 'chemical' type ways.