If you're playing the newest version, you require happiness and food equivalent to your population (though you should aim to have those numbers be equal to your population CAP so that you don't have issues once you grow).

Without upgrades, a brewery provides a bonus to each house next to it, providing one happiness to each house. Simplified, it provides one happiness to your total happiness per house next to it. As it does this, it consumes 5 wheat per season. When you upgrade the brewery, it produces 2 happiness per house adjacent and uses 10 wheat.

This means that you will be even on happiness to maximum population if you surround all 6 tiles around a brewery with level 1 houses. If you upgrade the brewery, then the houses can be upgraded to level 2 without any problems.

The other mechanic that causes unrest is food consumption. If your food output is less than your current population, then unrest will begin to accrue. One bakery consumes 5 wheat and produces 5 food per season, and consumes 10 wheat and produces 10 food once upgraded.

You will need:

• 3 level 1 bakeries to feed 15 level 1 houses (15 food to 15 max pop)
• 3 level 2 bakeries to feed 15 level 2 houses (30 food to 30 max pop)
• 3 level 2 bakeries to feed 10 level 3 houses (30 food to 30 max pop)

Of course, you also need to make sure you have enough wheat being produced to keep your breweries and bakeries running as well.

A farm produces 5 wheat per season at level 1, 10 at level 2 (copper tools), and 15 at level 3 (bronze tools). It will produce an additional 2 food if adjacent to a level 1 windmill, 4 food if next to a level 2 windmill, and an additional +2 if built on fertile soil.

6 level 1 farms around a level 1 windmill produce a total of 42 food. This can support two level 2 bakeries and breweries, which can support up to 20 population (8 level 2 homes and 4 level 1 homes) without producing any unrest. 11 of that population will be producing food, bread and beer for everyone else.

Another thing of note, if you have grapes that you can access, a winery produces 2 happiness per adjacent home at level 1, and 3 per adjacent home at level 2... and it doesn't eat into your wheat which means more bakeries as well. A level 2 winery can be surrounded by 6 fully upgraded homes without building unrest (but would require 2 upgraded bakeries to feed).

This is all going into the basics as well. You can also stack the effects of breweries/wineries on a house as well. Its possible to arrange 4 breweries and 5 bakeries in a way that provides enough happiness and food for 16 level 3 houses.

TL;DR -- Riots aren't broken and don't need to be fixed. What needs to be fixed is clarification of how the unrest and happiness mechanics work.