effects of water/grain ratio in mash

[wbc_leelee]

  Hi
Does anybody have any ideas on the effects of water/grain ratio in mash in relation to the amount of fermentables produced. Is a thin mash better for sugar conversion and extraction or is a thick mash better. I currently use 2.2lt per kilo.
regards
Andrew

[BeerSmith]

   The recommended water to grist ratio for the main conversion step (the part that takes place around 68 C or 154 F) in an infusion mash is usually in the 1.25 qt/lb to 1.5 qt/lb range, though you can easily go slightly higher or lower in a multi-step infusion.

 That converts to 2.6-3.4 l/kg if I did my math right.

 I know that lower temperature steps (i.e. protein rest) actually do better at slightly lower water to grist ratios.

 Also decoctions are generally done at much higher water to grist ratios to aid in the boiling of the mash.

Brad

[cj_in_j]

I generally start out with 2.5 l/kg. After 20 min or so, I add another 0.5 l/kg (I have a poorly insultated mash tun), and hold for 40 min. The brewpub I worked in always mashed at 3 l/kg, and the brewer claimed that that was best especially for British malts. It works well for me.

Now, the question about whether or not a thicker mash ends up with a more fermentable wort, I always get confused about that, but I think that thicker = more fermentable. But, temperature and time are just as important (or even more important). If you want more fermentable wort, mash at 149-151F for 1 hour or more. While most of the starches will be converted to sugars in a much shorter time, the sugars will continue breaking down from unfermentable to fermentable the more time you give it. (Rumor has it that the major breweries mash for 3-4 hours with their lite beers to help make them more fermentable.)